Cement CLI

- Resolves Issue #490
- Resolves Issue #487

.coveragerc

@@ -0,0 +1,2 @@
+[run]
+omit = cement/cli/contrib/*

CHANGELOG.md

@@ -36,6 +36,11 @@ Features:
 - `[ext.mustache]` Add MustacheTemplateHandler
 - `[ext.handlebars]` Add HandlebarsTemplateHandler
 - `[ext.jinja2]` Add Jinja2TemplateHandler
+- `[ext.generate]` Add Generate Extension
+    - [Issue #487](https://github.com/datafolklabs/cement/issues/487)
+- `[cli]` Add Cement CLI (includes ability to generate apps, plugins,
+    extensions, and scripts using the Generate Extension)
+    - [Issue #490](https://github.com/datafolklabs/cement/issues/490)
 
 
 Refactoring:
@@ -52,13 +57,13 @@ Incompatible:
 - `[core.handler]` Drop deprecated backend globals
 - `[core.hook]` Drop deprecated backend globals
 - `[core.controller]` Drop `CementBaseController`
-- `[ext.argcomplete]` No longer shipped with Cement.
-- `[ext.reload_config]` No longer shipped with Cement.
-- `[ext.configobj]` No longer shipped with Cement.
-- `[ext.json_configobj]` No longer shipped with Cement.
-- `[ext.yaml_configobj]` No longer shipped with Cement.
-- `[ext.genshi]` No longer shipped with Cement.
-- `[ext.argparse]` ArgparseController.Meta.default_func is not `_default`, and
+- `[ext.argcomplete]` Drop ArgComplete Extension
+- `[ext.reload_config]` Drop Reload Config Extension
+- `[ext.configobj]` Drop ConfigObj Extension
+- `[ext.json_configobj]` Drop JSON ConfigObj Extension
+- `[ext.yaml_configobj]` Drop YAML ConfigObj Extension
+- `[ext.genshi]` Drop Genshi Extension
+- `[ext.argparse]` `ArgparseController.Meta.default_func` is now `_default`, and
   will print help info and exit.  Can now set this to `None` as well to
   pass/exit.
     - [Issue #426](https://github.com/datafolklabs/cement/issues/426)

cement/__init__.py

@@ -1,7 +1,10 @@
 
 # flake8: noqa
 
-from .core.foundation import App
+from .core.foundation import App, TestApp
+from .core.exc import FrameworkError, InterfaceError, CaughtSignal
 from .ext.ext_argparse import ArgparseController as Controller
 from .ext.ext_argparse import expose as ex
-from .utils.misc import init_defaults
+from .utils.misc import init_defaults, minimal_logger
+from .utils import misc, fs, shell
+from .utils.version import get_version

cement/cli/contrib/jinja2/__init__.py

@@ -0,0 +1,83 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2
+    ~~~~~~
+
+    Jinja2 is a template engine written in pure Python.  It provides a
+    Django inspired non-XML syntax but supports inline expressions and
+    an optional sandboxed environment.
+
+    Nutshell
+    --------
+
+    Here a small example of a Jinja2 template::
+
+        {% extends 'base.html' %}
+        {% block title %}Memberlist{% endblock %}
+        {% block content %}
+          <ul>
+          {% for user in users %}
+            <li><a href="{{ user.url }}">{{ user.username }}</a></li>
+          {% endfor %}
+          </ul>
+        {% endblock %}
+
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+__docformat__ = 'restructuredtext en'
+__version__ = '2.10'
+
+# high level interface
+from jinja2.environment import Environment, Template
+
+# loaders
+from jinja2.loaders import BaseLoader, FileSystemLoader, PackageLoader, \
+     DictLoader, FunctionLoader, PrefixLoader, ChoiceLoader, \
+     ModuleLoader
+
+# bytecode caches
+from jinja2.bccache import BytecodeCache, FileSystemBytecodeCache, \
+     MemcachedBytecodeCache
+
+# undefined types
+from jinja2.runtime import Undefined, DebugUndefined, StrictUndefined, \
+     make_logging_undefined
+
+# exceptions
+from jinja2.exceptions import TemplateError, UndefinedError, \
+     TemplateNotFound, TemplatesNotFound, TemplateSyntaxError, \
+     TemplateAssertionError, TemplateRuntimeError
+
+# decorators and public utilities
+from jinja2.filters import environmentfilter, contextfilter, \
+     evalcontextfilter
+from jinja2.utils import Markup, escape, clear_caches, \
+     environmentfunction, evalcontextfunction, contextfunction, \
+     is_undefined, select_autoescape
+
+__all__ = [
+    'Environment', 'Template', 'BaseLoader', 'FileSystemLoader',
+    'PackageLoader', 'DictLoader', 'FunctionLoader', 'PrefixLoader',
+    'ChoiceLoader', 'BytecodeCache', 'FileSystemBytecodeCache',
+    'MemcachedBytecodeCache', 'Undefined', 'DebugUndefined',
+    'StrictUndefined', 'TemplateError', 'UndefinedError', 'TemplateNotFound',
+    'TemplatesNotFound', 'TemplateSyntaxError', 'TemplateAssertionError',
+    'TemplateRuntimeError',
+    'ModuleLoader', 'environmentfilter', 'contextfilter', 'Markup', 'escape',
+    'environmentfunction', 'contextfunction', 'clear_caches', 'is_undefined',
+    'evalcontextfilter', 'evalcontextfunction', 'make_logging_undefined',
+    'select_autoescape',
+]
+
+
+def _patch_async():
+    from jinja2.utils import have_async_gen
+    if have_async_gen:
+        from jinja2.asyncsupport import patch_all
+        patch_all()
+
+
+_patch_async()
+del _patch_async

cement/cli/contrib/jinja2/_compat.py

@@ -0,0 +1,99 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2._compat
+    ~~~~~~~~~~~~~~
+
+    Some py2/py3 compatibility support based on a stripped down
+    version of six so we don't have to depend on a specific version
+    of it.
+
+    :copyright: Copyright 2013 by the Jinja team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+import sys
+
+PY2 = sys.version_info[0] == 2
+PYPY = hasattr(sys, 'pypy_translation_info')
+_identity = lambda x: x
+
+
+if not PY2:
+    unichr = chr
+    range_type = range
+    text_type = str
+    string_types = (str,)
+    integer_types = (int,)
+
+    iterkeys = lambda d: iter(d.keys())
+    itervalues = lambda d: iter(d.values())
+    iteritems = lambda d: iter(d.items())
+
+    import pickle
+    from io import BytesIO, StringIO
+    NativeStringIO = StringIO
+
+    def reraise(tp, value, tb=None):
+        if value.__traceback__ is not tb:
+            raise value.with_traceback(tb)
+        raise value
+
+    ifilter = filter
+    imap = map
+    izip = zip
+    intern = sys.intern
+
+    implements_iterator = _identity
+    implements_to_string = _identity
+    encode_filename = _identity
+
+else:
+    unichr = unichr
+    text_type = unicode
+    range_type = xrange
+    string_types = (str, unicode)
+    integer_types = (int, long)
+
+    iterkeys = lambda d: d.iterkeys()
+    itervalues = lambda d: d.itervalues()
+    iteritems = lambda d: d.iteritems()
+
+    import cPickle as pickle
+    from cStringIO import StringIO as BytesIO, StringIO
+    NativeStringIO = BytesIO
+
+    exec('def reraise(tp, value, tb=None):\n raise tp, value, tb')
+
+    from itertools import imap, izip, ifilter
+    intern = intern
+
+    def implements_iterator(cls):
+        cls.next = cls.__next__
+        del cls.__next__
+        return cls
+
+    def implements_to_string(cls):
+        cls.__unicode__ = cls.__str__
+        cls.__str__ = lambda x: x.__unicode__().encode('utf-8')
+        return cls
+
+    def encode_filename(filename):
+        if isinstance(filename, unicode):
+            return filename.encode('utf-8')
+        return filename
+
+
+def with_metaclass(meta, *bases):
+    """Create a base class with a metaclass."""
+    # This requires a bit of explanation: the basic idea is to make a
+    # dummy metaclass for one level of class instantiation that replaces
+    # itself with the actual metaclass.
+    class metaclass(type):
+        def __new__(cls, name, this_bases, d):
+            return meta(name, bases, d)
+    return type.__new__(metaclass, 'temporary_class', (), {})
+
+
+try:
+    from urllib.parse import quote_from_bytes as url_quote
+except ImportError:
+    from urllib import quote as url_quote

cement/cli/contrib/jinja2/_identifier.py

@@ -0,0 +1,2 @@
+# generated by scripts/generate_identifier_pattern.py
+pattern = '·̀-ͯ·҃-֑҇-ׇֽֿׁׂׅׄؐ-ًؚ-ٰٟۖ-ۜ۟-۪ۤۧۨ-ܑۭܰ-݊ަ-ް߫-߳ࠖ-࠙ࠛ-ࠣࠥ-ࠧࠩ-࡙࠭-࡛ࣔ-ࣣ࣡-ःऺ-़ा-ॏ॑-ॗॢॣঁ-ঃ়া-ৄেৈো-্ৗৢৣਁ-ਃ਼ਾ-ੂੇੈੋ-੍ੑੰੱੵઁ-ઃ઼ા-ૅે-ૉો-્ૢૣଁ-ଃ଼ା-ୄେୈୋ-୍ୖୗୢୣஂா-ூெ-ைொ-்ௗఀ-ఃా-ౄె-ైొ-్ౕౖౢౣಁ-ಃ಼ಾ-ೄೆ-ೈೊ-್ೕೖೢೣഁ-ഃാ-ൄെ-ൈൊ-്ൗൢൣංඃ්ා-ුූෘ-ෟෲෳัิ-ฺ็-๎ັິ-ູົຼ່-ໍ༹༘༙༵༷༾༿ཱ-྄྆྇ྍ-ྗྙ-ྼ࿆ါ-ှၖ-ၙၞ-ၠၢ-ၤၧ-ၭၱ-ၴႂ-ႍႏႚ-ႝ፝-፟ᜒ-᜔ᜲ-᜴ᝒᝓᝲᝳ឴-៓៝᠋-᠍ᢅᢆᢩᤠ-ᤫᤰ-᤻ᨗ-ᨛᩕ-ᩞ᩠-᩿᩼᪰-᪽ᬀ-ᬄ᬴-᭄᭫-᭳ᮀ-ᮂᮡ-ᮭ᯦-᯳ᰤ-᰷᳐-᳔᳒-᳨᳭ᳲ-᳴᳸᳹᷀-᷵᷻-᷿‿⁀⁔⃐-⃥⃜⃡-⃰℘℮⳯-⵿⳱ⷠ-〪ⷿ-゙゚〯꙯ꙴ-꙽ꚞꚟ꛰꛱ꠂ꠆ꠋꠣ-ꠧꢀꢁꢴ-ꣅ꣠-꣱ꤦ-꤭ꥇ-꥓ꦀ-ꦃ꦳-꧀ꧥꨩ-ꨶꩃꩌꩍꩻ-ꩽꪰꪲ-ꪴꪷꪸꪾ꪿꫁ꫫ-ꫯꫵ꫶ꯣ-ꯪ꯬꯭ﬞ︀-️︠-︯︳︴﹍-﹏＿𐇽𐋠𐍶-𐍺𐨁-𐨃𐨅𐨆𐨌-𐨏𐨸-𐨿𐨺𐫦𐫥𑀀-𑀂𑀸-𑁆𑁿-𑂂𑂰-𑂺𑄀-𑄂𑄧-𑅳𑄴𑆀-𑆂𑆳-𑇊𑇀-𑇌𑈬-𑈷𑈾𑋟-𑋪𑌀-𑌃𑌼𑌾-𑍄𑍇𑍈𑍋-𑍍𑍗𑍢𑍣𑍦-𑍬𑍰-𑍴𑐵-𑑆𑒰-𑓃𑖯-𑖵𑖸-𑗀𑗜𑗝𑘰-𑙀𑚫-𑚷𑜝-𑜫𑰯-𑰶𑰸-𑰿𑲒-𑲧𑲩-𑲶𖫰-𖫴𖬰-𖬶𖽑-𖽾𖾏-𖾒𛲝𛲞𝅥-𝅩𝅭-𝅲𝅻-𝆂𝆅-𝆋𝆪-𝆭𝉂-𝉄𝨀-𝨶𝨻-𝩬𝩵𝪄𝪛-𝪟𝪡-𝪯𞀀-𞀆𞀈-𞀘𞀛-𞀡𞀣𞀤𞀦-𞣐𞀪-𞣖𞥄-𞥊󠄀-󠇯'

cement/cli/contrib/jinja2/asyncfilters.py

@@ -0,0 +1,146 @@
+from functools import wraps
+
+from jinja2.asyncsupport import auto_aiter
+from jinja2 import filters
+
+
+async def auto_to_seq(value):
+    seq = []
+    if hasattr(value, '__aiter__'):
+        async for item in value:
+            seq.append(item)
+    else:
+        for item in value:
+            seq.append(item)
+    return seq
+
+
+async def async_select_or_reject(args, kwargs, modfunc, lookup_attr):
+    seq, func = filters.prepare_select_or_reject(
+        args, kwargs, modfunc, lookup_attr)
+    if seq:
+        async for item in auto_aiter(seq):
+            if func(item):
+                yield item
+
+
+def dualfilter(normal_filter, async_filter):
+    wrap_evalctx = False
+    if getattr(normal_filter, 'environmentfilter', False):
+        is_async = lambda args: args[0].is_async
+        wrap_evalctx = False
+    else:
+        if not getattr(normal_filter, 'evalcontextfilter', False) and \
+           not getattr(normal_filter, 'contextfilter', False):
+            wrap_evalctx = True
+        is_async = lambda args: args[0].environment.is_async
+
+    @wraps(normal_filter)
+    def wrapper(*args, **kwargs):
+        b = is_async(args)
+        if wrap_evalctx:
+            args = args[1:]
+        if b:
+            return async_filter(*args, **kwargs)
+        return normal_filter(*args, **kwargs)
+
+    if wrap_evalctx:
+        wrapper.evalcontextfilter = True
+
+    wrapper.asyncfiltervariant = True
+
+    return wrapper
+
+
+def asyncfiltervariant(original):
+    def decorator(f):
+        return dualfilter(original, f)
+    return decorator
+
+
+@asyncfiltervariant(filters.do_first)
+async def do_first(environment, seq):
+    try:
+        return await auto_aiter(seq).__anext__()
+    except StopAsyncIteration:
+        return environment.undefined('No first item, sequence was empty.')
+
+
+@asyncfiltervariant(filters.do_groupby)
+async def do_groupby(environment, value, attribute):
+    expr = filters.make_attrgetter(environment, attribute)
+    return [filters._GroupTuple(key, await auto_to_seq(values))
+            for key, values in filters.groupby(sorted(
+                await auto_to_seq(value), key=expr), expr)]
+
+
+@asyncfiltervariant(filters.do_join)
+async def do_join(eval_ctx, value, d=u'', attribute=None):
+    return filters.do_join(eval_ctx, await auto_to_seq(value), d, attribute)
+
+
+@asyncfiltervariant(filters.do_list)
+async def do_list(value):
+    return await auto_to_seq(value)
+
+
+@asyncfiltervariant(filters.do_reject)
+async def do_reject(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: not x, False)
+
+
+@asyncfiltervariant(filters.do_rejectattr)
+async def do_rejectattr(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: not x, True)
+
+
+@asyncfiltervariant(filters.do_select)
+async def do_select(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: x, False)
+
+
+@asyncfiltervariant(filters.do_selectattr)
+async def do_selectattr(*args, **kwargs):
+    return async_select_or_reject(args, kwargs, lambda x: x, True)
+
+
+@asyncfiltervariant(filters.do_map)
+async def do_map(*args, **kwargs):
+    seq, func = filters.prepare_map(args, kwargs)
+    if seq:
+        async for item in auto_aiter(seq):
+            yield func(item)
+
+
+@asyncfiltervariant(filters.do_sum)
+async def do_sum(environment, iterable, attribute=None, start=0):
+    rv = start
+    if attribute is not None:
+        func = filters.make_attrgetter(environment, attribute)
+    else:
+        func = lambda x: x
+    async for item in auto_aiter(iterable):
+        rv += func(item)
+    return rv
+
+
+@asyncfiltervariant(filters.do_slice)
+async def do_slice(value, slices, fill_with=None):
+    return filters.do_slice(await auto_to_seq(value), slices, fill_with)
+
+
+ASYNC_FILTERS = {
+    'first':        do_first,
+    'groupby':      do_groupby,
+    'join':         do_join,
+    'list':         do_list,
+    # we intentionally do not support do_last because that would be
+    # ridiculous
+    'reject':       do_reject,
+    'rejectattr':   do_rejectattr,
+    'map':          do_map,
+    'select':       do_select,
+    'selectattr':   do_selectattr,
+    'sum':          do_sum,
+    'slice':        do_slice,
+}

cement/cli/contrib/jinja2/asyncsupport.py

@@ -0,0 +1,256 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.asyncsupport
+    ~~~~~~~~~~~~~~~~~~~
+
+    Has all the code for async support which is implemented as a patch
+    for supported Python versions.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import sys
+import asyncio
+import inspect
+from functools import update_wrapper
+
+from jinja2.utils import concat, internalcode, Markup
+from jinja2.environment import TemplateModule
+from jinja2.runtime import LoopContextBase, _last_iteration
+
+
+async def concat_async(async_gen):
+    rv = []
+    async def collect():
+        async for event in async_gen:
+            rv.append(event)
+    await collect()
+    return concat(rv)
+
+
+async def generate_async(self, *args, **kwargs):
+    vars = dict(*args, **kwargs)
+    try:
+        async for event in self.root_render_func(self.new_context(vars)):
+            yield event
+    except Exception:
+        exc_info = sys.exc_info()
+    else:
+        return
+    yield self.environment.handle_exception(exc_info, True)
+
+
+def wrap_generate_func(original_generate):
+    def _convert_generator(self, loop, args, kwargs):
+        async_gen = self.generate_async(*args, **kwargs)
+        try:
+            while 1:
+                yield loop.run_until_complete(async_gen.__anext__())
+        except StopAsyncIteration:
+            pass
+    def generate(self, *args, **kwargs):
+        if not self.environment.is_async:
+            return original_generate(self, *args, **kwargs)
+        return _convert_generator(self, asyncio.get_event_loop(), args, kwargs)
+    return update_wrapper(generate, original_generate)
+
+
+async def render_async(self, *args, **kwargs):
+    if not self.environment.is_async:
+        raise RuntimeError('The environment was not created with async mode '
+                           'enabled.')
+
+    vars = dict(*args, **kwargs)
+    ctx = self.new_context(vars)
+
+    try:
+        return await concat_async(self.root_render_func(ctx))
+    except Exception:
+        exc_info = sys.exc_info()
+    return self.environment.handle_exception(exc_info, True)
+
+
+def wrap_render_func(original_render):
+    def render(self, *args, **kwargs):
+        if not self.environment.is_async:
+            return original_render(self, *args, **kwargs)
+        loop = asyncio.get_event_loop()
+        return loop.run_until_complete(self.render_async(*args, **kwargs))
+    return update_wrapper(render, original_render)
+
+
+def wrap_block_reference_call(original_call):
+    @internalcode
+    async def async_call(self):
+        rv = await concat_async(self._stack[self._depth](self._context))
+        if self._context.eval_ctx.autoescape:
+            rv = Markup(rv)
+        return rv
+
+    @internalcode
+    def __call__(self):
+        if not self._context.environment.is_async:
+            return original_call(self)
+        return async_call(self)
+
+    return update_wrapper(__call__, original_call)
+
+
+def wrap_macro_invoke(original_invoke):
+    @internalcode
+    async def async_invoke(self, arguments, autoescape):
+        rv = await self._func(*arguments)
+        if autoescape:
+            rv = Markup(rv)
+        return rv
+
+    @internalcode
+    def _invoke(self, arguments, autoescape):
+        if not self._environment.is_async:
+            return original_invoke(self, arguments, autoescape)
+        return async_invoke(self, arguments, autoescape)
+    return update_wrapper(_invoke, original_invoke)
+
+
+@internalcode
+async def get_default_module_async(self):
+    if self._module is not None:
+        return self._module
+    self._module = rv = await self.make_module_async()
+    return rv
+
+
+def wrap_default_module(original_default_module):
+    @internalcode
+    def _get_default_module(self):
+        if self.environment.is_async:
+            raise RuntimeError('Template module attribute is unavailable '
+                               'in async mode')
+        return original_default_module(self)
+    return _get_default_module
+
+
+async def make_module_async(self, vars=None, shared=False, locals=None):
+    context = self.new_context(vars, shared, locals)
+    body_stream = []
+    async for item in self.root_render_func(context):
+        body_stream.append(item)
+    return TemplateModule(self, context, body_stream)
+
+
+def patch_template():
+    from jinja2 import Template
+    Template.generate = wrap_generate_func(Template.generate)
+    Template.generate_async = update_wrapper(
+        generate_async, Template.generate_async)
+    Template.render_async = update_wrapper(
+        render_async, Template.render_async)
+    Template.render = wrap_render_func(Template.render)
+    Template._get_default_module = wrap_default_module(
+        Template._get_default_module)
+    Template._get_default_module_async = get_default_module_async
+    Template.make_module_async = update_wrapper(
+        make_module_async, Template.make_module_async)
+
+
+def patch_runtime():
+    from jinja2.runtime import BlockReference, Macro
+    BlockReference.__call__ = wrap_block_reference_call(
+        BlockReference.__call__)
+    Macro._invoke = wrap_macro_invoke(Macro._invoke)
+
+
+def patch_filters():
+    from jinja2.filters import FILTERS
+    from jinja2.asyncfilters import ASYNC_FILTERS
+    FILTERS.update(ASYNC_FILTERS)
+
+
+def patch_all():
+    patch_template()
+    patch_runtime()
+    patch_filters()
+
+
+async def auto_await(value):
+    if inspect.isawaitable(value):
+        return await value
+    return value
+
+
+async def auto_aiter(iterable):
+    if hasattr(iterable, '__aiter__'):
+        async for item in iterable:
+            yield item
+        return
+    for item in iterable:
+        yield item
+
+
+class AsyncLoopContext(LoopContextBase):
+
+    def __init__(self, async_iterator, undefined, after, length, recurse=None,
+                 depth0=0):
+        LoopContextBase.__init__(self, undefined, recurse, depth0)
+        self._async_iterator = async_iterator
+        self._after = after
+        self._length = length
+
+    @property
+    def length(self):
+        if self._length is None:
+            raise TypeError('Loop length for some iterators cannot be '
+                            'lazily calculated in async mode')
+        return self._length
+
+    def __aiter__(self):
+        return AsyncLoopContextIterator(self)
+
+
+class AsyncLoopContextIterator(object):
+    __slots__ = ('context',)
+
+    def __init__(self, context):
+        self.context = context
+
+    def __aiter__(self):
+        return self
+
+    async def __anext__(self):
+        ctx = self.context
+        ctx.index0 += 1
+        if ctx._after is _last_iteration:
+            raise StopAsyncIteration()
+        ctx._before = ctx._current
+        ctx._current = ctx._after
+        try:
+            ctx._after = await ctx._async_iterator.__anext__()
+        except StopAsyncIteration:
+            ctx._after = _last_iteration
+        return ctx._current, ctx
+
+
+async def make_async_loop_context(iterable, undefined, recurse=None, depth0=0):
+    # Length is more complicated and less efficient in async mode.  The
+    # reason for this is that we cannot know if length will be used
+    # upfront but because length is a property we cannot lazily execute it
+    # later.  This means that we need to buffer it up and measure :(
+    #
+    # We however only do this for actual iterators, not for async
+    # iterators as blocking here does not seem like the best idea in the
+    # world.
+    try:
+        length = len(iterable)
+    except (TypeError, AttributeError):
+        if not hasattr(iterable, '__aiter__'):
+            iterable = tuple(iterable)
+            length = len(iterable)
+        else:
+            length = None
+    async_iterator = auto_aiter(iterable)
+    try:
+        after = await async_iterator.__anext__()
+    except StopAsyncIteration:
+        after = _last_iteration
+    return AsyncLoopContext(async_iterator, undefined, after, length, recurse,
+                            depth0)

cement/cli/contrib/jinja2/bccache.py

@@ -0,0 +1,362 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.bccache
+    ~~~~~~~~~~~~~~
+
+    This module implements the bytecode cache system Jinja is optionally
+    using.  This is useful if you have very complex template situations and
+    the compiliation of all those templates slow down your application too
+    much.
+
+    Situations where this is useful are often forking web applications that
+    are initialized on the first request.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD.
+"""
+from os import path, listdir
+import os
+import sys
+import stat
+import errno
+import marshal
+import tempfile
+import fnmatch
+from hashlib import sha1
+from jinja2.utils import open_if_exists
+from jinja2._compat import BytesIO, pickle, PY2, text_type
+
+
+# marshal works better on 3.x, one hack less required
+if not PY2:
+    marshal_dump = marshal.dump
+    marshal_load = marshal.load
+else:
+
+    def marshal_dump(code, f):
+        if isinstance(f, file):
+            marshal.dump(code, f)
+        else:
+            f.write(marshal.dumps(code))
+
+    def marshal_load(f):
+        if isinstance(f, file):
+            return marshal.load(f)
+        return marshal.loads(f.read())
+
+
+bc_version = 3
+
+# magic version used to only change with new jinja versions.  With 2.6
+# we change this to also take Python version changes into account.  The
+# reason for this is that Python tends to segfault if fed earlier bytecode
+# versions because someone thought it would be a good idea to reuse opcodes
+# or make Python incompatible with earlier versions.
+bc_magic = 'j2'.encode('ascii') + \
+    pickle.dumps(bc_version, 2) + \
+    pickle.dumps((sys.version_info[0] << 24) | sys.version_info[1])
+
+
+class Bucket(object):
+    """Buckets are used to store the bytecode for one template.  It's created
+    and initialized by the bytecode cache and passed to the loading functions.
+
+    The buckets get an internal checksum from the cache assigned and use this
+    to automatically reject outdated cache material.  Individual bytecode
+    cache subclasses don't have to care about cache invalidation.
+    """
+
+    def __init__(self, environment, key, checksum):
+        self.environment = environment
+        self.key = key
+        self.checksum = checksum
+        self.reset()
+
+    def reset(self):
+        """Resets the bucket (unloads the bytecode)."""
+        self.code = None
+
+    def load_bytecode(self, f):
+        """Loads bytecode from a file or file like object."""
+        # make sure the magic header is correct
+        magic = f.read(len(bc_magic))
+        if magic != bc_magic:
+            self.reset()
+            return
+        # the source code of the file changed, we need to reload
+        checksum = pickle.load(f)
+        if self.checksum != checksum:
+            self.reset()
+            return
+        # if marshal_load fails then we need to reload
+        try:
+            self.code = marshal_load(f)
+        except (EOFError, ValueError, TypeError):
+            self.reset()
+            return
+
+    def write_bytecode(self, f):
+        """Dump the bytecode into the file or file like object passed."""
+        if self.code is None:
+            raise TypeError('can\'t write empty bucket')
+        f.write(bc_magic)
+        pickle.dump(self.checksum, f, 2)
+        marshal_dump(self.code, f)
+
+    def bytecode_from_string(self, string):
+        """Load bytecode from a string."""
+        self.load_bytecode(BytesIO(string))
+
+    def bytecode_to_string(self):
+        """Return the bytecode as string."""
+        out = BytesIO()
+        self.write_bytecode(out)
+        return out.getvalue()
+
+
+class BytecodeCache(object):
+    """To implement your own bytecode cache you have to subclass this class
+    and override :meth:`load_bytecode` and :meth:`dump_bytecode`.  Both of
+    these methods are passed a :class:`~jinja2.bccache.Bucket`.
+
+    A very basic bytecode cache that saves the bytecode on the file system::
+
+        from os import path
+
+        class MyCache(BytecodeCache):
+
+            def __init__(self, directory):
+                self.directory = directory
+
+            def load_bytecode(self, bucket):
+                filename = path.join(self.directory, bucket.key)
+                if path.exists(filename):
+                    with open(filename, 'rb') as f:
+                        bucket.load_bytecode(f)
+
+            def dump_bytecode(self, bucket):
+                filename = path.join(self.directory, bucket.key)
+                with open(filename, 'wb') as f:
+                    bucket.write_bytecode(f)
+
+    A more advanced version of a filesystem based bytecode cache is part of
+    Jinja2.
+    """
+
+    def load_bytecode(self, bucket):
+        """Subclasses have to override this method to load bytecode into a
+        bucket.  If they are not able to find code in the cache for the
+        bucket, it must not do anything.
+        """
+        raise NotImplementedError()
+
+    def dump_bytecode(self, bucket):
+        """Subclasses have to override this method to write the bytecode
+        from a bucket back to the cache.  If it unable to do so it must not
+        fail silently but raise an exception.
+        """
+        raise NotImplementedError()
+
+    def clear(self):
+        """Clears the cache.  This method is not used by Jinja2 but should be
+        implemented to allow applications to clear the bytecode cache used
+        by a particular environment.
+        """
+
+    def get_cache_key(self, name, filename=None):
+        """Returns the unique hash key for this template name."""
+        hash = sha1(name.encode('utf-8'))
+        if filename is not None:
+            filename = '|' + filename
+            if isinstance(filename, text_type):
+                filename = filename.encode('utf-8')
+            hash.update(filename)
+        return hash.hexdigest()
+
+    def get_source_checksum(self, source):
+        """Returns a checksum for the source."""
+        return sha1(source.encode('utf-8')).hexdigest()
+
+    def get_bucket(self, environment, name, filename, source):
+        """Return a cache bucket for the given template.  All arguments are
+        mandatory but filename may be `None`.
+        """
+        key = self.get_cache_key(name, filename)
+        checksum = self.get_source_checksum(source)
+        bucket = Bucket(environment, key, checksum)
+        self.load_bytecode(bucket)
+        return bucket
+
+    def set_bucket(self, bucket):
+        """Put the bucket into the cache."""
+        self.dump_bytecode(bucket)
+
+
+class FileSystemBytecodeCache(BytecodeCache):
+    """A bytecode cache that stores bytecode on the filesystem.  It accepts
+    two arguments: The directory where the cache items are stored and a
+    pattern string that is used to build the filename.
+
+    If no directory is specified a default cache directory is selected.  On
+    Windows the user's temp directory is used, on UNIX systems a directory
+    is created for the user in the system temp directory.
+
+    The pattern can be used to have multiple separate caches operate on the
+    same directory.  The default pattern is ``'__jinja2_%s.cache'``.  ``%s``
+    is replaced with the cache key.
+
+    >>> bcc = FileSystemBytecodeCache('/tmp/jinja_cache', '%s.cache')
+
+    This bytecode cache supports clearing of the cache using the clear method.
+    """
+
+    def __init__(self, directory=None, pattern='__jinja2_%s.cache'):
+        if directory is None:
+            directory = self._get_default_cache_dir()
+        self.directory = directory
+        self.pattern = pattern
+
+    def _get_default_cache_dir(self):
+        def _unsafe_dir():
+            raise RuntimeError('Cannot determine safe temp directory.  You '
+                               'need to explicitly provide one.')
+
+        tmpdir = tempfile.gettempdir()
+
+        # On windows the temporary directory is used specific unless
+        # explicitly forced otherwise.  We can just use that.
+        if os.name == 'nt':
+            return tmpdir
+        if not hasattr(os, 'getuid'):
+            _unsafe_dir()
+
+        dirname = '_jinja2-cache-%d' % os.getuid()
+        actual_dir = os.path.join(tmpdir, dirname)
+
+        try:
+            os.mkdir(actual_dir, stat.S_IRWXU)
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+        try:
+            os.chmod(actual_dir, stat.S_IRWXU)
+            actual_dir_stat = os.lstat(actual_dir)
+            if actual_dir_stat.st_uid != os.getuid() \
+               or not stat.S_ISDIR(actual_dir_stat.st_mode) \
+               or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU:
+                _unsafe_dir()
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
+
+        actual_dir_stat = os.lstat(actual_dir)
+        if actual_dir_stat.st_uid != os.getuid() \
+           or not stat.S_ISDIR(actual_dir_stat.st_mode) \
+           or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU:
+            _unsafe_dir()
+
+        return actual_dir
+
+    def _get_cache_filename(self, bucket):
+        return path.join(self.directory, self.pattern % bucket.key)
+
+    def load_bytecode(self, bucket):
+        f = open_if_exists(self._get_cache_filename(bucket), 'rb')
+        if f is not None:
+            try:
+                bucket.load_bytecode(f)
+            finally:
+                f.close()
+
+    def dump_bytecode(self, bucket):
+        f = open(self._get_cache_filename(bucket), 'wb')
+        try:
+            bucket.write_bytecode(f)
+        finally:
+            f.close()
+
+    def clear(self):
+        # imported lazily here because google app-engine doesn't support
+        # write access on the file system and the function does not exist
+        # normally.
+        from os import remove
+        files = fnmatch.filter(listdir(self.directory), self.pattern % '*')
+        for filename in files:
+            try:
+                remove(path.join(self.directory, filename))
+            except OSError:
+                pass
+
+
+class MemcachedBytecodeCache(BytecodeCache):
+    """This class implements a bytecode cache that uses a memcache cache for
+    storing the information.  It does not enforce a specific memcache library
+    (tummy's memcache or cmemcache) but will accept any class that provides
+    the minimal interface required.
+
+    Libraries compatible with this class:
+
+    -   `werkzeug <http://werkzeug.pocoo.org/>`_.contrib.cache
+    -   `python-memcached <https://www.tummy.com/Community/software/python-memcached/>`_
+    -   `cmemcache <http://gijsbert.org/cmemcache/>`_
+
+    (Unfortunately the django cache interface is not compatible because it
+    does not support storing binary data, only unicode.  You can however pass
+    the underlying cache client to the bytecode cache which is available
+    as `django.core.cache.cache._client`.)
+
+    The minimal interface for the client passed to the constructor is this:
+
+    .. class:: MinimalClientInterface
+
+        .. method:: set(key, value[, timeout])
+
+            Stores the bytecode in the cache.  `value` is a string and
+            `timeout` the timeout of the key.  If timeout is not provided
+            a default timeout or no timeout should be assumed, if it's
+            provided it's an integer with the number of seconds the cache
+            item should exist.
+
+        .. method:: get(key)
+
+            Returns the value for the cache key.  If the item does not
+            exist in the cache the return value must be `None`.
+
+    The other arguments to the constructor are the prefix for all keys that
+    is added before the actual cache key and the timeout for the bytecode in
+    the cache system.  We recommend a high (or no) timeout.
+
+    This bytecode cache does not support clearing of used items in the cache.
+    The clear method is a no-operation function.
+
+    .. versionadded:: 2.7
+       Added support for ignoring memcache errors through the
+       `ignore_memcache_errors` parameter.
+    """
+
+    def __init__(self, client, prefix='jinja2/bytecode/', timeout=None,
+                 ignore_memcache_errors=True):
+        self.client = client
+        self.prefix = prefix
+        self.timeout = timeout
+        self.ignore_memcache_errors = ignore_memcache_errors
+
+    def load_bytecode(self, bucket):
+        try:
+            code = self.client.get(self.prefix + bucket.key)
+        except Exception:
+            if not self.ignore_memcache_errors:
+                raise
+            code = None
+        if code is not None:
+            bucket.bytecode_from_string(code)
+
+    def dump_bytecode(self, bucket):
+        args = (self.prefix + bucket.key, bucket.bytecode_to_string())
+        if self.timeout is not None:
+            args += (self.timeout,)
+        try:
+            self.client.set(*args)
+        except Exception:
+            if not self.ignore_memcache_errors:
+                raise

cement/cli/contrib/jinja2/constants.py

@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja.constants
+    ~~~~~~~~~~~~~~~
+
+    Various constants.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+
+#: list of lorem ipsum words used by the lipsum() helper function
+LOREM_IPSUM_WORDS = u'''\
+a ac accumsan ad adipiscing aenean aliquam aliquet amet ante aptent arcu at
+auctor augue bibendum blandit class commodo condimentum congue consectetuer
+consequat conubia convallis cras cubilia cum curabitur curae cursus dapibus
+diam dictum dictumst dignissim dis dolor donec dui duis egestas eget eleifend
+elementum elit enim erat eros est et etiam eu euismod facilisi facilisis fames
+faucibus felis fermentum feugiat fringilla fusce gravida habitant habitasse hac
+hendrerit hymenaeos iaculis id imperdiet in inceptos integer interdum ipsum
+justo lacinia lacus laoreet lectus leo libero ligula litora lobortis lorem
+luctus maecenas magna magnis malesuada massa mattis mauris metus mi molestie
+mollis montes morbi mus nam nascetur natoque nec neque netus nibh nisi nisl non
+nonummy nostra nulla nullam nunc odio orci ornare parturient pede pellentesque
+penatibus per pharetra phasellus placerat platea porta porttitor posuere
+potenti praesent pretium primis proin pulvinar purus quam quis quisque rhoncus
+ridiculus risus rutrum sagittis sapien scelerisque sed sem semper senectus sit
+sociis sociosqu sodales sollicitudin suscipit suspendisse taciti tellus tempor
+tempus tincidunt torquent tortor tristique turpis ullamcorper ultrices
+ultricies urna ut varius vehicula vel velit venenatis vestibulum vitae vivamus
+viverra volutpat vulputate'''

cement/cli/contrib/jinja2/debug.py

@@ -0,0 +1,372 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.debug
+    ~~~~~~~~~~~~
+
+    Implements the debug interface for Jinja.  This module does some pretty
+    ugly stuff with the Python traceback system in order to achieve tracebacks
+    with correct line numbers, locals and contents.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import sys
+import traceback
+from types import TracebackType, CodeType
+from jinja2.utils import missing, internal_code
+from jinja2.exceptions import TemplateSyntaxError
+from jinja2._compat import iteritems, reraise, PY2
+
+# on pypy we can take advantage of transparent proxies
+try:
+    from __pypy__ import tproxy
+except ImportError:
+    tproxy = None
+
+
+# how does the raise helper look like?
+try:
+    exec("raise TypeError, 'foo'")
+except SyntaxError:
+    raise_helper = 'raise __jinja_exception__[1]'
+except TypeError:
+    raise_helper = 'raise __jinja_exception__[0], __jinja_exception__[1]'
+
+
+class TracebackFrameProxy(object):
+    """Proxies a traceback frame."""
+
+    def __init__(self, tb):
+        self.tb = tb
+        self._tb_next = None
+
+    @property
+    def tb_next(self):
+        return self._tb_next
+
+    def set_next(self, next):
+        if tb_set_next is not None:
+            try:
+                tb_set_next(self.tb, next and next.tb or None)
+            except Exception:
+                # this function can fail due to all the hackery it does
+                # on various python implementations.  We just catch errors
+                # down and ignore them if necessary.
+                pass
+        self._tb_next = next
+
+    @property
+    def is_jinja_frame(self):
+        return '__jinja_template__' in self.tb.tb_frame.f_globals
+
+    def __getattr__(self, name):
+        return getattr(self.tb, name)
+
+
+def make_frame_proxy(frame):
+    proxy = TracebackFrameProxy(frame)
+    if tproxy is None:
+        return proxy
+    def operation_handler(operation, *args, **kwargs):
+        if operation in ('__getattribute__', '__getattr__'):
+            return getattr(proxy, args[0])
+        elif operation == '__setattr__':
+            proxy.__setattr__(*args, **kwargs)
+        else:
+            return getattr(proxy, operation)(*args, **kwargs)
+    return tproxy(TracebackType, operation_handler)
+
+
+class ProcessedTraceback(object):
+    """Holds a Jinja preprocessed traceback for printing or reraising."""
+
+    def __init__(self, exc_type, exc_value, frames):
+        assert frames, 'no frames for this traceback?'
+        self.exc_type = exc_type
+        self.exc_value = exc_value
+        self.frames = frames
+
+        # newly concatenate the frames (which are proxies)
+        prev_tb = None
+        for tb in self.frames:
+            if prev_tb is not None:
+                prev_tb.set_next(tb)
+            prev_tb = tb
+        prev_tb.set_next(None)
+
+    def render_as_text(self, limit=None):
+        """Return a string with the traceback."""
+        lines = traceback.format_exception(self.exc_type, self.exc_value,
+                                           self.frames[0], limit=limit)
+        return ''.join(lines).rstrip()
+
+    def render_as_html(self, full=False):
+        """Return a unicode string with the traceback as rendered HTML."""
+        from jinja2.debugrenderer import render_traceback
+        return u'%s\n\n<!--\n%s\n-->' % (
+            render_traceback(self, full=full),
+            self.render_as_text().decode('utf-8', 'replace')
+        )
+
+    @property
+    def is_template_syntax_error(self):
+        """`True` if this is a template syntax error."""
+        return isinstance(self.exc_value, TemplateSyntaxError)
+
+    @property
+    def exc_info(self):
+        """Exception info tuple with a proxy around the frame objects."""
+        return self.exc_type, self.exc_value, self.frames[0]
+
+    @property
+    def standard_exc_info(self):
+        """Standard python exc_info for re-raising"""
+        tb = self.frames[0]
+        # the frame will be an actual traceback (or transparent proxy) if
+        # we are on pypy or a python implementation with support for tproxy
+        if type(tb) is not TracebackType:
+            tb = tb.tb
+        return self.exc_type, self.exc_value, tb
+
+
+def make_traceback(exc_info, source_hint=None):
+    """Creates a processed traceback object from the exc_info."""
+    exc_type, exc_value, tb = exc_info
+    if isinstance(exc_value, TemplateSyntaxError):
+        exc_info = translate_syntax_error(exc_value, source_hint)
+        initial_skip = 0
+    else:
+        initial_skip = 1
+    return translate_exception(exc_info, initial_skip)
+
+
+def translate_syntax_error(error, source=None):
+    """Rewrites a syntax error to please traceback systems."""
+    error.source = source
+    error.translated = True
+    exc_info = (error.__class__, error, None)
+    filename = error.filename
+    if filename is None:
+        filename = '<unknown>'
+    return fake_exc_info(exc_info, filename, error.lineno)
+
+
+def translate_exception(exc_info, initial_skip=0):
+    """If passed an exc_info it will automatically rewrite the exceptions
+    all the way down to the correct line numbers and frames.
+    """
+    tb = exc_info[2]
+    frames = []
+
+    # skip some internal frames if wanted
+    for x in range(initial_skip):
+        if tb is not None:
+            tb = tb.tb_next
+    initial_tb = tb
+
+    while tb is not None:
+        # skip frames decorated with @internalcode.  These are internal
+        # calls we can't avoid and that are useless in template debugging
+        # output.
+        if tb.tb_frame.f_code in internal_code:
+            tb = tb.tb_next
+            continue
+
+        # save a reference to the next frame if we override the current
+        # one with a faked one.
+        next = tb.tb_next
+
+        # fake template exceptions
+        template = tb.tb_frame.f_globals.get('__jinja_template__')
+        if template is not None:
+            lineno = template.get_corresponding_lineno(tb.tb_lineno)
+            tb = fake_exc_info(exc_info[:2] + (tb,), template.filename,
+                               lineno)[2]
+
+        frames.append(make_frame_proxy(tb))
+        tb = next
+
+    # if we don't have any exceptions in the frames left, we have to
+    # reraise it unchanged.
+    # XXX: can we backup here?  when could this happen?
+    if not frames:
+        reraise(exc_info[0], exc_info[1], exc_info[2])
+
+    return ProcessedTraceback(exc_info[0], exc_info[1], frames)
+
+
+def get_jinja_locals(real_locals):
+    ctx = real_locals.get('context')
+    if ctx:
+        locals = ctx.get_all().copy()
+    else:
+        locals = {}
+
+    local_overrides = {}
+
+    for name, value in iteritems(real_locals):
+        if not name.startswith('l_') or value is missing:
+            continue
+        try:
+            _, depth, name = name.split('_', 2)
+            depth = int(depth)
+        except ValueError:
+            continue
+        cur_depth = local_overrides.get(name, (-1,))[0]
+        if cur_depth < depth:
+            local_overrides[name] = (depth, value)
+
+    for name, (_, value) in iteritems(local_overrides):
+        if value is missing:
+            locals.pop(name, None)
+        else:
+            locals[name] = value
+
+    return locals
+
+
+def fake_exc_info(exc_info, filename, lineno):
+    """Helper for `translate_exception`."""
+    exc_type, exc_value, tb = exc_info
+
+    # figure the real context out
+    if tb is not None:
+        locals = get_jinja_locals(tb.tb_frame.f_locals)
+
+        # if there is a local called __jinja_exception__, we get
+        # rid of it to not break the debug functionality.
+        locals.pop('__jinja_exception__', None)
+    else:
+        locals = {}
+
+    # assamble fake globals we need
+    globals = {
+        '__name__':             filename,
+        '__file__':             filename,
+        '__jinja_exception__':  exc_info[:2],
+
+        # we don't want to keep the reference to the template around
+        # to not cause circular dependencies, but we mark it as Jinja
+        # frame for the ProcessedTraceback
+        '__jinja_template__':   None
+    }
+
+    # and fake the exception
+    code = compile('\n' * (lineno - 1) + raise_helper, filename, 'exec')
+
+    # if it's possible, change the name of the code.  This won't work
+    # on some python environments such as google appengine
+    try:
+        if tb is None:
+            location = 'template'
+        else:
+            function = tb.tb_frame.f_code.co_name
+            if function == 'root':
+                location = 'top-level template code'
+            elif function.startswith('block_'):
+                location = 'block "%s"' % function[6:]
+            else:
+                location = 'template'
+
+        if PY2:
+            code = CodeType(0, code.co_nlocals, code.co_stacksize,
+                            code.co_flags, code.co_code, code.co_consts,
+                            code.co_names, code.co_varnames, filename,
+                            location, code.co_firstlineno,
+                            code.co_lnotab, (), ())
+        else:
+            code = CodeType(0, code.co_kwonlyargcount,
+                            code.co_nlocals, code.co_stacksize,
+                            code.co_flags, code.co_code, code.co_consts,
+                            code.co_names, code.co_varnames, filename,
+                            location, code.co_firstlineno,
+                            code.co_lnotab, (), ())
+    except Exception as e:
+        pass
+
+    # execute the code and catch the new traceback
+    try:
+        exec(code, globals, locals)
+    except:
+        exc_info = sys.exc_info()
+        new_tb = exc_info[2].tb_next
+
+    # return without this frame
+    return exc_info[:2] + (new_tb,)
+
+
+def _init_ugly_crap():
+    """This function implements a few ugly things so that we can patch the
+    traceback objects.  The function returned allows resetting `tb_next` on
+    any python traceback object.  Do not attempt to use this on non cpython
+    interpreters
+    """
+    import ctypes
+    from types import TracebackType
+
+    if PY2:
+        # figure out size of _Py_ssize_t for Python 2:
+        if hasattr(ctypes.pythonapi, 'Py_InitModule4_64'):
+            _Py_ssize_t = ctypes.c_int64
+        else:
+            _Py_ssize_t = ctypes.c_int
+    else:
+        # platform ssize_t on Python 3
+        _Py_ssize_t = ctypes.c_ssize_t
+
+    # regular python
+    class _PyObject(ctypes.Structure):
+        pass
+    _PyObject._fields_ = [
+        ('ob_refcnt', _Py_ssize_t),
+        ('ob_type', ctypes.POINTER(_PyObject))
+    ]
+
+    # python with trace
+    if hasattr(sys, 'getobjects'):
+        class _PyObject(ctypes.Structure):
+            pass
+        _PyObject._fields_ = [
+            ('_ob_next', ctypes.POINTER(_PyObject)),
+            ('_ob_prev', ctypes.POINTER(_PyObject)),
+            ('ob_refcnt', _Py_ssize_t),
+            ('ob_type', ctypes.POINTER(_PyObject))
+        ]
+
+    class _Traceback(_PyObject):
+        pass
+    _Traceback._fields_ = [
+        ('tb_next', ctypes.POINTER(_Traceback)),
+        ('tb_frame', ctypes.POINTER(_PyObject)),
+        ('tb_lasti', ctypes.c_int),
+        ('tb_lineno', ctypes.c_int)
+    ]
+
+    def tb_set_next(tb, next):
+        """Set the tb_next attribute of a traceback object."""
+        if not (isinstance(tb, TracebackType) and
+                (next is None or isinstance(next, TracebackType))):
+            raise TypeError('tb_set_next arguments must be traceback objects')
+        obj = _Traceback.from_address(id(tb))
+        if tb.tb_next is not None:
+            old = _Traceback.from_address(id(tb.tb_next))
+            old.ob_refcnt -= 1
+        if next is None:
+            obj.tb_next = ctypes.POINTER(_Traceback)()
+        else:
+            next = _Traceback.from_address(id(next))
+            next.ob_refcnt += 1
+            obj.tb_next = ctypes.pointer(next)
+
+    return tb_set_next
+
+
+# try to get a tb_set_next implementation if we don't have transparent
+# proxies.
+tb_set_next = None
+if tproxy is None:
+    try:
+        tb_set_next = _init_ugly_crap()
+    except:
+        pass
+    del _init_ugly_crap

cement/cli/contrib/jinja2/defaults.py

@@ -0,0 +1,56 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.defaults
+    ~~~~~~~~~~~~~~~
+
+    Jinja default filters and tags.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+from jinja2._compat import range_type
+from jinja2.utils import generate_lorem_ipsum, Cycler, Joiner, Namespace
+
+
+# defaults for the parser / lexer
+BLOCK_START_STRING = '{%'
+BLOCK_END_STRING = '%}'
+VARIABLE_START_STRING = '{{'
+VARIABLE_END_STRING = '}}'
+COMMENT_START_STRING = '{#'
+COMMENT_END_STRING = '#}'
+LINE_STATEMENT_PREFIX = None
+LINE_COMMENT_PREFIX = None
+TRIM_BLOCKS = False
+LSTRIP_BLOCKS = False
+NEWLINE_SEQUENCE = '\n'
+KEEP_TRAILING_NEWLINE = False
+
+
+# default filters, tests and namespace
+from jinja2.filters import FILTERS as DEFAULT_FILTERS
+from jinja2.tests import TESTS as DEFAULT_TESTS
+DEFAULT_NAMESPACE = {
+    'range':        range_type,
+    'dict':         dict,
+    'lipsum':       generate_lorem_ipsum,
+    'cycler':       Cycler,
+    'joiner':       Joiner,
+    'namespace':    Namespace
+}
+
+
+# default policies
+DEFAULT_POLICIES = {
+    'compiler.ascii_str':   True,
+    'urlize.rel':           'noopener',
+    'urlize.target':        None,
+    'truncate.leeway':      5,
+    'json.dumps_function':  None,
+    'json.dumps_kwargs':    {'sort_keys': True},
+    'ext.i18n.trimmed':     False,
+}
+
+
+# export all constants
+__all__ = tuple(x for x in locals().keys() if x.isupper())

cement/cli/contrib/jinja2/exceptions.py

@@ -0,0 +1,146 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.exceptions
+    ~~~~~~~~~~~~~~~~~
+
+    Jinja exceptions.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+from jinja2._compat import imap, text_type, PY2, implements_to_string
+
+
+class TemplateError(Exception):
+    """Baseclass for all template errors."""
+
+    if PY2:
+        def __init__(self, message=None):
+            if message is not None:
+                message = text_type(message).encode('utf-8')
+            Exception.__init__(self, message)
+
+        @property
+        def message(self):
+            if self.args:
+                message = self.args[0]
+                if message is not None:
+                    return message.decode('utf-8', 'replace')
+
+        def __unicode__(self):
+            return self.message or u''
+    else:
+        def __init__(self, message=None):
+            Exception.__init__(self, message)
+
+        @property
+        def message(self):
+            if self.args:
+                message = self.args[0]
+                if message is not None:
+                    return message
+
+
+@implements_to_string
+class TemplateNotFound(IOError, LookupError, TemplateError):
+    """Raised if a template does not exist."""
+
+    # looks weird, but removes the warning descriptor that just
+    # bogusly warns us about message being deprecated
+    message = None
+
+    def __init__(self, name, message=None):
+        IOError.__init__(self)
+        if message is None:
+            message = name
+        self.message = message
+        self.name = name
+        self.templates = [name]
+
+    def __str__(self):
+        return self.message
+
+
+class TemplatesNotFound(TemplateNotFound):
+    """Like :class:`TemplateNotFound` but raised if multiple templates
+    are selected.  This is a subclass of :class:`TemplateNotFound`
+    exception, so just catching the base exception will catch both.
+
+    .. versionadded:: 2.2
+    """
+
+    def __init__(self, names=(), message=None):
+        if message is None:
+            message = u'none of the templates given were found: ' + \
+                      u', '.join(imap(text_type, names))
+        TemplateNotFound.__init__(self, names and names[-1] or None, message)
+        self.templates = list(names)
+
+
+@implements_to_string
+class TemplateSyntaxError(TemplateError):
+    """Raised to tell the user that there is a problem with the template."""
+
+    def __init__(self, message, lineno, name=None, filename=None):
+        TemplateError.__init__(self, message)
+        self.lineno = lineno
+        self.name = name
+        self.filename = filename
+        self.source = None
+
+        # this is set to True if the debug.translate_syntax_error
+        # function translated the syntax error into a new traceback
+        self.translated = False
+
+    def __str__(self):
+        # for translated errors we only return the message
+        if self.translated:
+            return self.message
+
+        # otherwise attach some stuff
+        location = 'line %d' % self.lineno
+        name = self.filename or self.name
+        if name:
+            location = 'File "%s", %s' % (name, location)
+        lines = [self.message, '  ' + location]
+
+        # if the source is set, add the line to the output
+        if self.source is not None:
+            try:
+                line = self.source.splitlines()[self.lineno - 1]
+            except IndexError:
+                line = None
+            if line:
+                lines.append('    ' + line.strip())
+
+        return u'\n'.join(lines)
+
+
+class TemplateAssertionError(TemplateSyntaxError):
+    """Like a template syntax error, but covers cases where something in the
+    template caused an error at compile time that wasn't necessarily caused
+    by a syntax error.  However it's a direct subclass of
+    :exc:`TemplateSyntaxError` and has the same attributes.
+    """
+
+
+class TemplateRuntimeError(TemplateError):
+    """A generic runtime error in the template engine.  Under some situations
+    Jinja may raise this exception.
+    """
+
+
+class UndefinedError(TemplateRuntimeError):
+    """Raised if a template tries to operate on :class:`Undefined`."""
+
+
+class SecurityError(TemplateRuntimeError):
+    """Raised if a template tries to do something insecure if the
+    sandbox is enabled.
+    """
+
+
+class FilterArgumentError(TemplateRuntimeError):
+    """This error is raised if a filter was called with inappropriate
+    arguments
+    """

cement/cli/contrib/jinja2/ext.py

@@ -0,0 +1,627 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.ext
+    ~~~~~~~~~~
+
+    Jinja extensions allow to add custom tags similar to the way django custom
+    tags work.  By default two example extensions exist: an i18n and a cache
+    extension.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD.
+"""
+import re
+
+from jinja2 import nodes
+from jinja2.defaults import BLOCK_START_STRING, \
+     BLOCK_END_STRING, VARIABLE_START_STRING, VARIABLE_END_STRING, \
+     COMMENT_START_STRING, COMMENT_END_STRING, LINE_STATEMENT_PREFIX, \
+     LINE_COMMENT_PREFIX, TRIM_BLOCKS, NEWLINE_SEQUENCE, \
+     KEEP_TRAILING_NEWLINE, LSTRIP_BLOCKS
+from jinja2.environment import Environment
+from jinja2.runtime import concat
+from jinja2.exceptions import TemplateAssertionError, TemplateSyntaxError
+from jinja2.utils import contextfunction, import_string, Markup
+from jinja2._compat import with_metaclass, string_types, iteritems
+
+
+# the only real useful gettext functions for a Jinja template.  Note
+# that ugettext must be assigned to gettext as Jinja doesn't support
+# non unicode strings.
+GETTEXT_FUNCTIONS = ('_', 'gettext', 'ngettext')
+
+
+class ExtensionRegistry(type):
+    """Gives the extension an unique identifier."""
+
+    def __new__(cls, name, bases, d):
+        rv = type.__new__(cls, name, bases, d)
+        rv.identifier = rv.__module__ + '.' + rv.__name__
+        return rv
+
+
+class Extension(with_metaclass(ExtensionRegistry, object)):
+    """Extensions can be used to add extra functionality to the Jinja template
+    system at the parser level.  Custom extensions are bound to an environment
+    but may not store environment specific data on `self`.  The reason for
+    this is that an extension can be bound to another environment (for
+    overlays) by creating a copy and reassigning the `environment` attribute.
+
+    As extensions are created by the environment they cannot accept any
+    arguments for configuration.  One may want to work around that by using
+    a factory function, but that is not possible as extensions are identified
+    by their import name.  The correct way to configure the extension is
+    storing the configuration values on the environment.  Because this way the
+    environment ends up acting as central configuration storage the
+    attributes may clash which is why extensions have to ensure that the names
+    they choose for configuration are not too generic.  ``prefix`` for example
+    is a terrible name, ``fragment_cache_prefix`` on the other hand is a good
+    name as includes the name of the extension (fragment cache).
+    """
+
+    #: if this extension parses this is the list of tags it's listening to.
+    tags = set()
+
+    #: the priority of that extension.  This is especially useful for
+    #: extensions that preprocess values.  A lower value means higher
+    #: priority.
+    #:
+    #: .. versionadded:: 2.4
+    priority = 100
+
+    def __init__(self, environment):
+        self.environment = environment
+
+    def bind(self, environment):
+        """Create a copy of this extension bound to another environment."""
+        rv = object.__new__(self.__class__)
+        rv.__dict__.update(self.__dict__)
+        rv.environment = environment
+        return rv
+
+    def preprocess(self, source, name, filename=None):
+        """This method is called before the actual lexing and can be used to
+        preprocess the source.  The `filename` is optional.  The return value
+        must be the preprocessed source.
+        """
+        return source
+
+    def filter_stream(self, stream):
+        """It's passed a :class:`~jinja2.lexer.TokenStream` that can be used
+        to filter tokens returned.  This method has to return an iterable of
+        :class:`~jinja2.lexer.Token`\\s, but it doesn't have to return a
+        :class:`~jinja2.lexer.TokenStream`.
+
+        In the `ext` folder of the Jinja2 source distribution there is a file
+        called `inlinegettext.py` which implements a filter that utilizes this
+        method.
+        """
+        return stream
+
+    def parse(self, parser):
+        """If any of the :attr:`tags` matched this method is called with the
+        parser as first argument.  The token the parser stream is pointing at
+        is the name token that matched.  This method has to return one or a
+        list of multiple nodes.
+        """
+        raise NotImplementedError()
+
+    def attr(self, name, lineno=None):
+        """Return an attribute node for the current extension.  This is useful
+        to pass constants on extensions to generated template code.
+
+        ::
+
+            self.attr('_my_attribute', lineno=lineno)
+        """
+        return nodes.ExtensionAttribute(self.identifier, name, lineno=lineno)
+
+    def call_method(self, name, args=None, kwargs=None, dyn_args=None,
+                    dyn_kwargs=None, lineno=None):
+        """Call a method of the extension.  This is a shortcut for
+        :meth:`attr` + :class:`jinja2.nodes.Call`.
+        """
+        if args is None:
+            args = []
+        if kwargs is None:
+            kwargs = []
+        return nodes.Call(self.attr(name, lineno=lineno), args, kwargs,
+                          dyn_args, dyn_kwargs, lineno=lineno)
+
+
+@contextfunction
+def _gettext_alias(__context, *args, **kwargs):
+    return __context.call(__context.resolve('gettext'), *args, **kwargs)
+
+
+def _make_new_gettext(func):
+    @contextfunction
+    def gettext(__context, __string, **variables):
+        rv = __context.call(func, __string)
+        if __context.eval_ctx.autoescape:
+            rv = Markup(rv)
+        return rv % variables
+    return gettext
+
+
+def _make_new_ngettext(func):
+    @contextfunction
+    def ngettext(__context, __singular, __plural, __num, **variables):
+        variables.setdefault('num', __num)
+        rv = __context.call(func, __singular, __plural, __num)
+        if __context.eval_ctx.autoescape:
+            rv = Markup(rv)
+        return rv % variables
+    return ngettext
+
+
+class InternationalizationExtension(Extension):
+    """This extension adds gettext support to Jinja2."""
+    tags = set(['trans'])
+
+    # TODO: the i18n extension is currently reevaluating values in a few
+    # situations.  Take this example:
+    #   {% trans count=something() %}{{ count }} foo{% pluralize
+    #     %}{{ count }} fooss{% endtrans %}
+    # something is called twice here.  One time for the gettext value and
+    # the other time for the n-parameter of the ngettext function.
+
+    def __init__(self, environment):
+        Extension.__init__(self, environment)
+        environment.globals['_'] = _gettext_alias
+        environment.extend(
+            install_gettext_translations=self._install,
+            install_null_translations=self._install_null,
+            install_gettext_callables=self._install_callables,
+            uninstall_gettext_translations=self._uninstall,
+            extract_translations=self._extract,
+            newstyle_gettext=False
+        )
+
+    def _install(self, translations, newstyle=None):
+        gettext = getattr(translations, 'ugettext', None)
+        if gettext is None:
+            gettext = translations.gettext
+        ngettext = getattr(translations, 'ungettext', None)
+        if ngettext is None:
+            ngettext = translations.ngettext
+        self._install_callables(gettext, ngettext, newstyle)
+
+    def _install_null(self, newstyle=None):
+        self._install_callables(
+            lambda x: x,
+            lambda s, p, n: (n != 1 and (p,) or (s,))[0],
+            newstyle
+        )
+
+    def _install_callables(self, gettext, ngettext, newstyle=None):
+        if newstyle is not None:
+            self.environment.newstyle_gettext = newstyle
+        if self.environment.newstyle_gettext:
+            gettext = _make_new_gettext(gettext)
+            ngettext = _make_new_ngettext(ngettext)
+        self.environment.globals.update(
+            gettext=gettext,
+            ngettext=ngettext
+        )
+
+    def _uninstall(self, translations):
+        for key in 'gettext', 'ngettext':
+            self.environment.globals.pop(key, None)
+
+    def _extract(self, source, gettext_functions=GETTEXT_FUNCTIONS):
+        if isinstance(source, string_types):
+            source = self.environment.parse(source)
+        return extract_from_ast(source, gettext_functions)
+
+    def parse(self, parser):
+        """Parse a translatable tag."""
+        lineno = next(parser.stream).lineno
+        num_called_num = False
+
+        # find all the variables referenced.  Additionally a variable can be
+        # defined in the body of the trans block too, but this is checked at
+        # a later state.
+        plural_expr = None
+        plural_expr_assignment = None
+        variables = {}
+        trimmed = None
+        while parser.stream.current.type != 'block_end':
+            if variables:
+                parser.stream.expect('comma')
+
+            # skip colon for python compatibility
+            if parser.stream.skip_if('colon'):
+                break
+
+            name = parser.stream.expect('name')
+            if name.value in variables:
+                parser.fail('translatable variable %r defined twice.' %
+                            name.value, name.lineno,
+                            exc=TemplateAssertionError)
+
+            # expressions
+            if parser.stream.current.type == 'assign':
+                next(parser.stream)
+                variables[name.value] = var = parser.parse_expression()
+            elif trimmed is None and name.value in ('trimmed', 'notrimmed'):
+                trimmed = name.value == 'trimmed'
+                continue
+            else:
+                variables[name.value] = var = nodes.Name(name.value, 'load')
+
+            if plural_expr is None:
+                if isinstance(var, nodes.Call):
+                    plural_expr = nodes.Name('_trans', 'load')
+                    variables[name.value] = plural_expr
+                    plural_expr_assignment = nodes.Assign(
+                        nodes.Name('_trans', 'store'), var)
+                else:
+                    plural_expr = var
+                num_called_num = name.value == 'num'
+
+        parser.stream.expect('block_end')
+
+        plural = None
+        have_plural = False
+        referenced = set()
+
+        # now parse until endtrans or pluralize
+        singular_names, singular = self._parse_block(parser, True)
+        if singular_names:
+            referenced.update(singular_names)
+            if plural_expr is None:
+                plural_expr = nodes.Name(singular_names[0], 'load')
+                num_called_num = singular_names[0] == 'num'
+
+        # if we have a pluralize block, we parse that too
+        if parser.stream.current.test('name:pluralize'):
+            have_plural = True
+            next(parser.stream)
+            if parser.stream.current.type != 'block_end':
+                name = parser.stream.expect('name')
+                if name.value not in variables:
+                    parser.fail('unknown variable %r for pluralization' %
+                                name.value, name.lineno,
+                                exc=TemplateAssertionError)
+                plural_expr = variables[name.value]
+                num_called_num = name.value == 'num'
+            parser.stream.expect('block_end')
+            plural_names, plural = self._parse_block(parser, False)
+            next(parser.stream)
+            referenced.update(plural_names)
+        else:
+            next(parser.stream)
+
+        # register free names as simple name expressions
+        for var in referenced:
+            if var not in variables:
+                variables[var] = nodes.Name(var, 'load')
+
+        if not have_plural:
+            plural_expr = None
+        elif plural_expr is None:
+            parser.fail('pluralize without variables', lineno)
+
+        if trimmed is None:
+            trimmed = self.environment.policies['ext.i18n.trimmed']
+        if trimmed:
+            singular = self._trim_whitespace(singular)
+            if plural:
+                plural = self._trim_whitespace(plural)
+
+        node = self._make_node(singular, plural, variables, plural_expr,
+                               bool(referenced),
+                               num_called_num and have_plural)
+        node.set_lineno(lineno)
+        if plural_expr_assignment is not None:
+            return [plural_expr_assignment, node]
+        else:
+            return node
+
+    def _trim_whitespace(self, string, _ws_re=re.compile(r'\s*\n\s*')):
+        return _ws_re.sub(' ', string.strip())
+
+    def _parse_block(self, parser, allow_pluralize):
+        """Parse until the next block tag with a given name."""
+        referenced = []
+        buf = []
+        while 1:
+            if parser.stream.current.type == 'data':
+                buf.append(parser.stream.current.value.replace('%', '%%'))
+                next(parser.stream)
+            elif parser.stream.current.type == 'variable_begin':
+                next(parser.stream)
+                name = parser.stream.expect('name').value
+                referenced.append(name)
+                buf.append('%%(%s)s' % name)
+                parser.stream.expect('variable_end')
+            elif parser.stream.current.type == 'block_begin':
+                next(parser.stream)
+                if parser.stream.current.test('name:endtrans'):
+                    break
+                elif parser.stream.current.test('name:pluralize'):
+                    if allow_pluralize:
+                        break
+                    parser.fail('a translatable section can have only one '
+                                'pluralize section')
+                parser.fail('control structures in translatable sections are '
+                            'not allowed')
+            elif parser.stream.eos:
+                parser.fail('unclosed translation block')
+            else:
+                assert False, 'internal parser error'
+
+        return referenced, concat(buf)
+
+    def _make_node(self, singular, plural, variables, plural_expr,
+                   vars_referenced, num_called_num):
+        """Generates a useful node from the data provided."""
+        # no variables referenced?  no need to escape for old style
+        # gettext invocations only if there are vars.
+        if not vars_referenced and not self.environment.newstyle_gettext:
+            singular = singular.replace('%%', '%')
+            if plural:
+                plural = plural.replace('%%', '%')
+
+        # singular only:
+        if plural_expr is None:
+            gettext = nodes.Name('gettext', 'load')
+            node = nodes.Call(gettext, [nodes.Const(singular)],
+                              [], None, None)
+
+        # singular and plural
+        else:
+            ngettext = nodes.Name('ngettext', 'load')
+            node = nodes.Call(ngettext, [
+                nodes.Const(singular),
+                nodes.Const(plural),
+                plural_expr
+            ], [], None, None)
+
+        # in case newstyle gettext is used, the method is powerful
+        # enough to handle the variable expansion and autoescape
+        # handling itself
+        if self.environment.newstyle_gettext:
+            for key, value in iteritems(variables):
+                # the function adds that later anyways in case num was
+                # called num, so just skip it.
+                if num_called_num and key == 'num':
+                    continue
+                node.kwargs.append(nodes.Keyword(key, value))
+
+        # otherwise do that here
+        else:
+            # mark the return value as safe if we are in an
+            # environment with autoescaping turned on
+            node = nodes.MarkSafeIfAutoescape(node)
+            if variables:
+                node = nodes.Mod(node, nodes.Dict([
+                    nodes.Pair(nodes.Const(key), value)
+                    for key, value in variables.items()
+                ]))
+        return nodes.Output([node])
+
+
+class ExprStmtExtension(Extension):
+    """Adds a `do` tag to Jinja2 that works like the print statement just
+    that it doesn't print the return value.
+    """
+    tags = set(['do'])
+
+    def parse(self, parser):
+        node = nodes.ExprStmt(lineno=next(parser.stream).lineno)
+        node.node = parser.parse_tuple()
+        return node
+
+
+class LoopControlExtension(Extension):
+    """Adds break and continue to the template engine."""
+    tags = set(['break', 'continue'])
+
+    def parse(self, parser):
+        token = next(parser.stream)
+        if token.value == 'break':
+            return nodes.Break(lineno=token.lineno)
+        return nodes.Continue(lineno=token.lineno)
+
+
+class WithExtension(Extension):
+    pass
+
+
+class AutoEscapeExtension(Extension):
+    pass
+
+
+def extract_from_ast(node, gettext_functions=GETTEXT_FUNCTIONS,
+                     babel_style=True):
+    """Extract localizable strings from the given template node.  Per
+    default this function returns matches in babel style that means non string
+    parameters as well as keyword arguments are returned as `None`.  This
+    allows Babel to figure out what you really meant if you are using
+    gettext functions that allow keyword arguments for placeholder expansion.
+    If you don't want that behavior set the `babel_style` parameter to `False`
+    which causes only strings to be returned and parameters are always stored
+    in tuples.  As a consequence invalid gettext calls (calls without a single
+    string parameter or string parameters after non-string parameters) are
+    skipped.
+
+    This example explains the behavior:
+
+    >>> from jinja2 import Environment
+    >>> env = Environment()
+    >>> node = env.parse('{{ (_("foo"), _(), ngettext("foo", "bar", 42)) }}')
+    >>> list(extract_from_ast(node))
+    [(1, '_', 'foo'), (1, '_', ()), (1, 'ngettext', ('foo', 'bar', None))]
+    >>> list(extract_from_ast(node, babel_style=False))
+    [(1, '_', ('foo',)), (1, 'ngettext', ('foo', 'bar'))]
+
+    For every string found this function yields a ``(lineno, function,
+    message)`` tuple, where:
+
+    * ``lineno`` is the number of the line on which the string was found,
+    * ``function`` is the name of the ``gettext`` function used (if the
+      string was extracted from embedded Python code), and
+    *  ``message`` is the string itself (a ``unicode`` object, or a tuple
+       of ``unicode`` objects for functions with multiple string arguments).
+
+    This extraction function operates on the AST and is because of that unable
+    to extract any comments.  For comment support you have to use the babel
+    extraction interface or extract comments yourself.
+    """
+    for node in node.find_all(nodes.Call):
+        if not isinstance(node.node, nodes.Name) or \
+           node.node.name not in gettext_functions:
+            continue
+
+        strings = []
+        for arg in node.args:
+            if isinstance(arg, nodes.Const) and \
+               isinstance(arg.value, string_types):
+                strings.append(arg.value)
+            else:
+                strings.append(None)
+
+        for arg in node.kwargs:
+            strings.append(None)
+        if node.dyn_args is not None:
+            strings.append(None)
+        if node.dyn_kwargs is not None:
+            strings.append(None)
+
+        if not babel_style:
+            strings = tuple(x for x in strings if x is not None)
+            if not strings:
+                continue
+        else:
+            if len(strings) == 1:
+                strings = strings[0]
+            else:
+                strings = tuple(strings)
+        yield node.lineno, node.node.name, strings
+
+
+class _CommentFinder(object):
+    """Helper class to find comments in a token stream.  Can only
+    find comments for gettext calls forwards.  Once the comment
+    from line 4 is found, a comment for line 1 will not return a
+    usable value.
+    """
+
+    def __init__(self, tokens, comment_tags):
+        self.tokens = tokens
+        self.comment_tags = comment_tags
+        self.offset = 0
+        self.last_lineno = 0
+
+    def find_backwards(self, offset):
+        try:
+            for _, token_type, token_value in \
+                    reversed(self.tokens[self.offset:offset]):
+                if token_type in ('comment', 'linecomment'):
+                    try:
+                        prefix, comment = token_value.split(None, 1)
+                    except ValueError:
+                        continue
+                    if prefix in self.comment_tags:
+                        return [comment.rstrip()]
+            return []
+        finally:
+            self.offset = offset
+
+    def find_comments(self, lineno):
+        if not self.comment_tags or self.last_lineno > lineno:
+            return []
+        for idx, (token_lineno, _, _) in enumerate(self.tokens[self.offset:]):
+            if token_lineno > lineno:
+                return self.find_backwards(self.offset + idx)
+        return self.find_backwards(len(self.tokens))
+
+
+def babel_extract(fileobj, keywords, comment_tags, options):
+    """Babel extraction method for Jinja templates.
+
+    .. versionchanged:: 2.3
+       Basic support for translation comments was added.  If `comment_tags`
+       is now set to a list of keywords for extraction, the extractor will
+       try to find the best preceeding comment that begins with one of the
+       keywords.  For best results, make sure to not have more than one
+       gettext call in one line of code and the matching comment in the
+       same line or the line before.
+
+    .. versionchanged:: 2.5.1
+       The `newstyle_gettext` flag can be set to `True` to enable newstyle
+       gettext calls.
+
+    .. versionchanged:: 2.7
+       A `silent` option can now be provided.  If set to `False` template
+       syntax errors are propagated instead of being ignored.
+
+    :param fileobj: the file-like object the messages should be extracted from
+    :param keywords: a list of keywords (i.e. function names) that should be
+                     recognized as translation functions
+    :param comment_tags: a list of translator tags to search for and include
+                         in the results.
+    :param options: a dictionary of additional options (optional)
+    :return: an iterator over ``(lineno, funcname, message, comments)`` tuples.
+             (comments will be empty currently)
+    """
+    extensions = set()
+    for extension in options.get('extensions', '').split(','):
+        extension = extension.strip()
+        if not extension:
+            continue
+        extensions.add(import_string(extension))
+    if InternationalizationExtension not in extensions:
+        extensions.add(InternationalizationExtension)
+
+    def getbool(options, key, default=False):
+        return options.get(key, str(default)).lower() in \
+            ('1', 'on', 'yes', 'true')
+
+    silent = getbool(options, 'silent', True)
+    environment = Environment(
+        options.get('block_start_string', BLOCK_START_STRING),
+        options.get('block_end_string', BLOCK_END_STRING),
+        options.get('variable_start_string', VARIABLE_START_STRING),
+        options.get('variable_end_string', VARIABLE_END_STRING),
+        options.get('comment_start_string', COMMENT_START_STRING),
+        options.get('comment_end_string', COMMENT_END_STRING),
+        options.get('line_statement_prefix') or LINE_STATEMENT_PREFIX,
+        options.get('line_comment_prefix') or LINE_COMMENT_PREFIX,
+        getbool(options, 'trim_blocks', TRIM_BLOCKS),
+        getbool(options, 'lstrip_blocks', LSTRIP_BLOCKS),
+        NEWLINE_SEQUENCE,
+        getbool(options, 'keep_trailing_newline', KEEP_TRAILING_NEWLINE),
+        frozenset(extensions),
+        cache_size=0,
+        auto_reload=False
+    )
+
+    if getbool(options, 'trimmed'):
+        environment.policies['ext.i18n.trimmed'] = True
+    if getbool(options, 'newstyle_gettext'):
+        environment.newstyle_gettext = True
+
+    source = fileobj.read().decode(options.get('encoding', 'utf-8'))
+    try:
+        node = environment.parse(source)
+        tokens = list(environment.lex(environment.preprocess(source)))
+    except TemplateSyntaxError as e:
+        if not silent:
+            raise
+        # skip templates with syntax errors
+        return
+
+    finder = _CommentFinder(tokens, comment_tags)
+    for lineno, func, message in extract_from_ast(node, keywords):
+        yield lineno, func, message, finder.find_comments(lineno)
+
+
+#: nicer import names
+i18n = InternationalizationExtension
+do = ExprStmtExtension
+loopcontrols = LoopControlExtension
+with_ = WithExtension
+autoescape = AutoEscapeExtension

cement/cli/contrib/jinja2/idtracking.py

@@ -0,0 +1,286 @@
+from jinja2.visitor import NodeVisitor
+from jinja2._compat import iteritems
+
+
+VAR_LOAD_PARAMETER = 'param'
+VAR_LOAD_RESOLVE = 'resolve'
+VAR_LOAD_ALIAS = 'alias'
+VAR_LOAD_UNDEFINED = 'undefined'
+
+
+def find_symbols(nodes, parent_symbols=None):
+    sym = Symbols(parent=parent_symbols)
+    visitor = FrameSymbolVisitor(sym)
+    for node in nodes:
+        visitor.visit(node)
+    return sym
+
+
+def symbols_for_node(node, parent_symbols=None):
+    sym = Symbols(parent=parent_symbols)
+    sym.analyze_node(node)
+    return sym
+
+
+class Symbols(object):
+
+    def __init__(self, parent=None, level=None):
+        if level is None:
+            if parent is None:
+                level = 0
+            else:
+                level = parent.level + 1
+        self.level = level
+        self.parent = parent
+        self.refs = {}
+        self.loads = {}
+        self.stores = set()
+
+    def analyze_node(self, node, **kwargs):
+        visitor = RootVisitor(self)
+        visitor.visit(node, **kwargs)
+
+    def _define_ref(self, name, load=None):
+        ident = 'l_%d_%s' % (self.level, name)
+        self.refs[name] = ident
+        if load is not None:
+            self.loads[ident] = load
+        return ident
+
+    def find_load(self, target):
+        if target in self.loads:
+            return self.loads[target]
+        if self.parent is not None:
+            return self.parent.find_load(target)
+
+    def find_ref(self, name):
+        if name in self.refs:
+            return self.refs[name]
+        if self.parent is not None:
+            return self.parent.find_ref(name)
+
+    def ref(self, name):
+        rv = self.find_ref(name)
+        if rv is None:
+            raise AssertionError('Tried to resolve a name to a reference that '
+                                 'was unknown to the frame (%r)' % name)
+        return rv
+
+    def copy(self):
+        rv = object.__new__(self.__class__)
+        rv.__dict__.update(self.__dict__)
+        rv.refs = self.refs.copy()
+        rv.loads = self.loads.copy()
+        rv.stores = self.stores.copy()
+        return rv
+
+    def store(self, name):
+        self.stores.add(name)
+
+        # If we have not see the name referenced yet, we need to figure
+        # out what to set it to.
+        if name not in self.refs:
+            # If there is a parent scope we check if the name has a
+            # reference there.  If it does it means we might have to alias
+            # to a variable there.
+            if self.parent is not None:
+                outer_ref = self.parent.find_ref(name)
+                if outer_ref is not None:
+                    self._define_ref(name, load=(VAR_LOAD_ALIAS, outer_ref))
+                    return
+
+            # Otherwise we can just set it to undefined.
+            self._define_ref(name, load=(VAR_LOAD_UNDEFINED, None))
+
+    def declare_parameter(self, name):
+        self.stores.add(name)
+        return self._define_ref(name, load=(VAR_LOAD_PARAMETER, None))
+
+    def load(self, name):
+        target = self.find_ref(name)
+        if target is None:
+            self._define_ref(name, load=(VAR_LOAD_RESOLVE, name))
+
+    def branch_update(self, branch_symbols):
+        stores = {}
+        for branch in branch_symbols:
+            for target in branch.stores:
+                if target in self.stores:
+                    continue
+                stores[target] = stores.get(target, 0) + 1
+
+        for sym in branch_symbols:
+            self.refs.update(sym.refs)
+            self.loads.update(sym.loads)
+            self.stores.update(sym.stores)
+
+        for name, branch_count in iteritems(stores):
+            if branch_count == len(branch_symbols):
+                continue
+            target = self.find_ref(name)
+            assert target is not None, 'should not happen'
+
+            if self.parent is not None:
+                outer_target = self.parent.find_ref(name)
+                if outer_target is not None:
+                    self.loads[target] = (VAR_LOAD_ALIAS, outer_target)
+                    continue
+            self.loads[target] = (VAR_LOAD_RESOLVE, name)
+
+    def dump_stores(self):
+        rv = {}
+        node = self
+        while node is not None:
+            for name in node.stores:
+                if name not in rv:
+                    rv[name] = self.find_ref(name)
+            node = node.parent
+        return rv
+
+    def dump_param_targets(self):
+        rv = set()
+        node = self
+        while node is not None:
+            for target, (instr, _) in iteritems(self.loads):
+                if instr == VAR_LOAD_PARAMETER:
+                    rv.add(target)
+            node = node.parent
+        return rv
+
+
+class RootVisitor(NodeVisitor):
+
+    def __init__(self, symbols):
+        self.sym_visitor = FrameSymbolVisitor(symbols)
+
+    def _simple_visit(self, node, **kwargs):
+        for child in node.iter_child_nodes():
+            self.sym_visitor.visit(child)
+
+    visit_Template = visit_Block = visit_Macro = visit_FilterBlock = \
+        visit_Scope = visit_If = visit_ScopedEvalContextModifier = \
+        _simple_visit
+
+    def visit_AssignBlock(self, node, **kwargs):
+        for child in node.body:
+            self.sym_visitor.visit(child)
+
+    def visit_CallBlock(self, node, **kwargs):
+        for child in node.iter_child_nodes(exclude=('call',)):
+            self.sym_visitor.visit(child)
+
+    def visit_OverlayScope(self, node, **kwargs):
+        for child in node.body:
+            self.sym_visitor.visit(child)
+
+    def visit_For(self, node, for_branch='body', **kwargs):
+        if for_branch == 'body':
+            self.sym_visitor.visit(node.target, store_as_param=True)
+            branch = node.body
+        elif for_branch == 'else':
+            branch = node.else_
+        elif for_branch == 'test':
+            self.sym_visitor.visit(node.target, store_as_param=True)
+            if node.test is not None:
+                self.sym_visitor.visit(node.test)
+            return
+        else:
+            raise RuntimeError('Unknown for branch')
+        for item in branch or ():
+            self.sym_visitor.visit(item)
+
+    def visit_With(self, node, **kwargs):
+        for target in node.targets:
+            self.sym_visitor.visit(target)
+        for child in node.body:
+            self.sym_visitor.visit(child)
+
+    def generic_visit(self, node, *args, **kwargs):
+        raise NotImplementedError('Cannot find symbols for %r' %
+                                  node.__class__.__name__)
+
+
+class FrameSymbolVisitor(NodeVisitor):
+    """A visitor for `Frame.inspect`."""
+
+    def __init__(self, symbols):
+        self.symbols = symbols
+
+    def visit_Name(self, node, store_as_param=False, **kwargs):
+        """All assignments to names go through this function."""
+        if store_as_param or node.ctx == 'param':
+            self.symbols.declare_parameter(node.name)
+        elif node.ctx == 'store':
+            self.symbols.store(node.name)
+        elif node.ctx == 'load':
+            self.symbols.load(node.name)
+
+    def visit_NSRef(self, node, **kwargs):
+        self.symbols.load(node.name)
+
+    def visit_If(self, node, **kwargs):
+        self.visit(node.test, **kwargs)
+
+        original_symbols = self.symbols
+
+        def inner_visit(nodes):
+            self.symbols = rv = original_symbols.copy()
+            for subnode in nodes:
+                self.visit(subnode, **kwargs)
+            self.symbols = original_symbols
+            return rv
+
+        body_symbols = inner_visit(node.body)
+        elif_symbols = inner_visit(node.elif_)
+        else_symbols = inner_visit(node.else_ or ())
+
+        self.symbols.branch_update([body_symbols, elif_symbols, else_symbols])
+
+    def visit_Macro(self, node, **kwargs):
+        self.symbols.store(node.name)
+
+    def visit_Import(self, node, **kwargs):
+        self.generic_visit(node, **kwargs)
+        self.symbols.store(node.target)
+
+    def visit_FromImport(self, node, **kwargs):
+        self.generic_visit(node, **kwargs)
+        for name in node.names:
+            if isinstance(name, tuple):
+                self.symbols.store(name[1])
+            else:
+                self.symbols.store(name)
+
+    def visit_Assign(self, node, **kwargs):
+        """Visit assignments in the correct order."""
+        self.visit(node.node, **kwargs)
+        self.visit(node.target, **kwargs)
+
+    def visit_For(self, node, **kwargs):
+        """Visiting stops at for blocks.  However the block sequence
+        is visited as part of the outer scope.
+        """
+        self.visit(node.iter, **kwargs)
+
+    def visit_CallBlock(self, node, **kwargs):
+        self.visit(node.call, **kwargs)
+
+    def visit_FilterBlock(self, node, **kwargs):
+        self.visit(node.filter, **kwargs)
+
+    def visit_With(self, node, **kwargs):
+        for target in node.values:
+            self.visit(target)
+
+    def visit_AssignBlock(self, node, **kwargs):
+        """Stop visiting at block assigns."""
+        self.visit(node.target, **kwargs)
+
+    def visit_Scope(self, node, **kwargs):
+        """Stop visiting at scopes."""
+
+    def visit_Block(self, node, **kwargs):
+        """Stop visiting at blocks."""
+
+    def visit_OverlayScope(self, node, **kwargs):
+        """Do not visit into overlay scopes."""

cement/cli/contrib/jinja2/lexer.py

@@ -0,0 +1,739 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.lexer
+    ~~~~~~~~~~~~
+
+    This module implements a Jinja / Python combination lexer. The
+    `Lexer` class provided by this module is used to do some preprocessing
+    for Jinja.
+
+    On the one hand it filters out invalid operators like the bitshift
+    operators we don't allow in templates. On the other hand it separates
+    template code and python code in expressions.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import re
+from collections import deque
+from operator import itemgetter
+
+from jinja2._compat import implements_iterator, intern, iteritems, text_type
+from jinja2.exceptions import TemplateSyntaxError
+from jinja2.utils import LRUCache
+
+# cache for the lexers. Exists in order to be able to have multiple
+# environments with the same lexer
+_lexer_cache = LRUCache(50)
+
+# static regular expressions
+whitespace_re = re.compile(r'\s+', re.U)
+string_re = re.compile(r"('([^'\\]*(?:\\.[^'\\]*)*)'"
+                       r'|"([^"\\]*(?:\\.[^"\\]*)*)")', re.S)
+integer_re = re.compile(r'\d+')
+
+try:
+    # check if this Python supports Unicode identifiers
+    compile('föö', '<unknown>', 'eval')
+except SyntaxError:
+    # no Unicode support, use ASCII identifiers
+    name_re = re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*')
+    check_ident = False
+else:
+    # Unicode support, build a pattern to match valid characters, and set flag
+    # to use str.isidentifier to validate during lexing
+    from jinja2 import _identifier
+    name_re = re.compile(r'[\w{0}]+'.format(_identifier.pattern))
+    check_ident = True
+    # remove the pattern from memory after building the regex
+    import sys
+    del sys.modules['jinja2._identifier']
+    import jinja2
+    del jinja2._identifier
+    del _identifier
+
+float_re = re.compile(r'(?<!\.)\d+\.\d+')
+newline_re = re.compile(r'(\r\n|\r|\n)')
+
+# internal the tokens and keep references to them
+TOKEN_ADD = intern('add')
+TOKEN_ASSIGN = intern('assign')
+TOKEN_COLON = intern('colon')
+TOKEN_COMMA = intern('comma')
+TOKEN_DIV = intern('div')
+TOKEN_DOT = intern('dot')
+TOKEN_EQ = intern('eq')
+TOKEN_FLOORDIV = intern('floordiv')
+TOKEN_GT = intern('gt')
+TOKEN_GTEQ = intern('gteq')
+TOKEN_LBRACE = intern('lbrace')
+TOKEN_LBRACKET = intern('lbracket')
+TOKEN_LPAREN = intern('lparen')
+TOKEN_LT = intern('lt')
+TOKEN_LTEQ = intern('lteq')
+TOKEN_MOD = intern('mod')
+TOKEN_MUL = intern('mul')
+TOKEN_NE = intern('ne')
+TOKEN_PIPE = intern('pipe')
+TOKEN_POW = intern('pow')
+TOKEN_RBRACE = intern('rbrace')
+TOKEN_RBRACKET = intern('rbracket')
+TOKEN_RPAREN = intern('rparen')
+TOKEN_SEMICOLON = intern('semicolon')
+TOKEN_SUB = intern('sub')
+TOKEN_TILDE = intern('tilde')
+TOKEN_WHITESPACE = intern('whitespace')
+TOKEN_FLOAT = intern('float')
+TOKEN_INTEGER = intern('integer')
+TOKEN_NAME = intern('name')
+TOKEN_STRING = intern('string')
+TOKEN_OPERATOR = intern('operator')
+TOKEN_BLOCK_BEGIN = intern('block_begin')
+TOKEN_BLOCK_END = intern('block_end')
+TOKEN_VARIABLE_BEGIN = intern('variable_begin')
+TOKEN_VARIABLE_END = intern('variable_end')
+TOKEN_RAW_BEGIN = intern('raw_begin')
+TOKEN_RAW_END = intern('raw_end')
+TOKEN_COMMENT_BEGIN = intern('comment_begin')
+TOKEN_COMMENT_END = intern('comment_end')
+TOKEN_COMMENT = intern('comment')
+TOKEN_LINESTATEMENT_BEGIN = intern('linestatement_begin')
+TOKEN_LINESTATEMENT_END = intern('linestatement_end')
+TOKEN_LINECOMMENT_BEGIN = intern('linecomment_begin')
+TOKEN_LINECOMMENT_END = intern('linecomment_end')
+TOKEN_LINECOMMENT = intern('linecomment')
+TOKEN_DATA = intern('data')
+TOKEN_INITIAL = intern('initial')
+TOKEN_EOF = intern('eof')
+
+# bind operators to token types
+operators = {
+    '+':            TOKEN_ADD,
+    '-':            TOKEN_SUB,
+    '/':            TOKEN_DIV,
+    '//':           TOKEN_FLOORDIV,
+    '*':            TOKEN_MUL,
+    '%':            TOKEN_MOD,
+    '**':           TOKEN_POW,
+    '~':            TOKEN_TILDE,
+    '[':            TOKEN_LBRACKET,
+    ']':            TOKEN_RBRACKET,
+    '(':            TOKEN_LPAREN,
+    ')':            TOKEN_RPAREN,
+    '{':            TOKEN_LBRACE,
+    '}':            TOKEN_RBRACE,
+    '==':           TOKEN_EQ,
+    '!=':           TOKEN_NE,
+    '>':            TOKEN_GT,
+    '>=':           TOKEN_GTEQ,
+    '<':            TOKEN_LT,
+    '<=':           TOKEN_LTEQ,
+    '=':            TOKEN_ASSIGN,
+    '.':            TOKEN_DOT,
+    ':':            TOKEN_COLON,
+    '|':            TOKEN_PIPE,
+    ',':            TOKEN_COMMA,
+    ';':            TOKEN_SEMICOLON
+}
+
+reverse_operators = dict([(v, k) for k, v in iteritems(operators)])
+assert len(operators) == len(reverse_operators), 'operators dropped'
+operator_re = re.compile('(%s)' % '|'.join(re.escape(x) for x in
+                         sorted(operators, key=lambda x: -len(x))))
+
+ignored_tokens = frozenset([TOKEN_COMMENT_BEGIN, TOKEN_COMMENT,
+                            TOKEN_COMMENT_END, TOKEN_WHITESPACE,
+                            TOKEN_LINECOMMENT_BEGIN, TOKEN_LINECOMMENT_END,
+                            TOKEN_LINECOMMENT])
+ignore_if_empty = frozenset([TOKEN_WHITESPACE, TOKEN_DATA,
+                             TOKEN_COMMENT, TOKEN_LINECOMMENT])
+
+
+def _describe_token_type(token_type):
+    if token_type in reverse_operators:
+        return reverse_operators[token_type]
+    return {
+        TOKEN_COMMENT_BEGIN:        'begin of comment',
+        TOKEN_COMMENT_END:          'end of comment',
+        TOKEN_COMMENT:              'comment',
+        TOKEN_LINECOMMENT:          'comment',
+        TOKEN_BLOCK_BEGIN:          'begin of statement block',
+        TOKEN_BLOCK_END:            'end of statement block',
+        TOKEN_VARIABLE_BEGIN:       'begin of print statement',
+        TOKEN_VARIABLE_END:         'end of print statement',
+        TOKEN_LINESTATEMENT_BEGIN:  'begin of line statement',
+        TOKEN_LINESTATEMENT_END:    'end of line statement',
+        TOKEN_DATA:                 'template data / text',
+        TOKEN_EOF:                  'end of template'
+    }.get(token_type, token_type)
+
+
+def describe_token(token):
+    """Returns a description of the token."""
+    if token.type == 'name':
+        return token.value
+    return _describe_token_type(token.type)
+
+
+def describe_token_expr(expr):
+    """Like `describe_token` but for token expressions."""
+    if ':' in expr:
+        type, value = expr.split(':', 1)
+        if type == 'name':
+            return value
+    else:
+        type = expr
+    return _describe_token_type(type)
+
+
+def count_newlines(value):
+    """Count the number of newline characters in the string.  This is
+    useful for extensions that filter a stream.
+    """
+    return len(newline_re.findall(value))
+
+
+def compile_rules(environment):
+    """Compiles all the rules from the environment into a list of rules."""
+    e = re.escape
+    rules = [
+        (len(environment.comment_start_string), 'comment',
+         e(environment.comment_start_string)),
+        (len(environment.block_start_string), 'block',
+         e(environment.block_start_string)),
+        (len(environment.variable_start_string), 'variable',
+         e(environment.variable_start_string))
+    ]
+
+    if environment.line_statement_prefix is not None:
+        rules.append((len(environment.line_statement_prefix), 'linestatement',
+                      r'^[ \t\v]*' + e(environment.line_statement_prefix)))
+    if environment.line_comment_prefix is not None:
+        rules.append((len(environment.line_comment_prefix), 'linecomment',
+                      r'(?:^|(?<=\S))[^\S\r\n]*' +
+                      e(environment.line_comment_prefix)))
+
+    return [x[1:] for x in sorted(rules, reverse=True)]
+
+
+class Failure(object):
+    """Class that raises a `TemplateSyntaxError` if called.
+    Used by the `Lexer` to specify known errors.
+    """
+
+    def __init__(self, message, cls=TemplateSyntaxError):
+        self.message = message
+        self.error_class = cls
+
+    def __call__(self, lineno, filename):
+        raise self.error_class(self.message, lineno, filename)
+
+
+class Token(tuple):
+    """Token class."""
+    __slots__ = ()
+    lineno, type, value = (property(itemgetter(x)) for x in range(3))
+
+    def __new__(cls, lineno, type, value):
+        return tuple.__new__(cls, (lineno, intern(str(type)), value))
+
+    def __str__(self):
+        if self.type in reverse_operators:
+            return reverse_operators[self.type]
+        elif self.type == 'name':
+            return self.value
+        return self.type
+
+    def test(self, expr):
+        """Test a token against a token expression.  This can either be a
+        token type or ``'token_type:token_value'``.  This can only test
+        against string values and types.
+        """
+        # here we do a regular string equality check as test_any is usually
+        # passed an iterable of not interned strings.
+        if self.type == expr:
+            return True
+        elif ':' in expr:
+            return expr.split(':', 1) == [self.type, self.value]
+        return False
+
+    def test_any(self, *iterable):
+        """Test against multiple token expressions."""
+        for expr in iterable:
+            if self.test(expr):
+                return True
+        return False
+
+    def __repr__(self):
+        return 'Token(%r, %r, %r)' % (
+            self.lineno,
+            self.type,
+            self.value
+        )
+
+
+@implements_iterator
+class TokenStreamIterator(object):
+    """The iterator for tokenstreams.  Iterate over the stream
+    until the eof token is reached.
+    """
+
+    def __init__(self, stream):
+        self.stream = stream
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        token = self.stream.current
+        if token.type is TOKEN_EOF:
+            self.stream.close()
+            raise StopIteration()
+        next(self.stream)
+        return token
+
+
+@implements_iterator
+class TokenStream(object):
+    """A token stream is an iterable that yields :class:`Token`\\s.  The
+    parser however does not iterate over it but calls :meth:`next` to go
+    one token ahead.  The current active token is stored as :attr:`current`.
+    """
+
+    def __init__(self, generator, name, filename):
+        self._iter = iter(generator)
+        self._pushed = deque()
+        self.name = name
+        self.filename = filename
+        self.closed = False
+        self.current = Token(1, TOKEN_INITIAL, '')
+        next(self)
+
+    def __iter__(self):
+        return TokenStreamIterator(self)
+
+    def __bool__(self):
+        return bool(self._pushed) or self.current.type is not TOKEN_EOF
+    __nonzero__ = __bool__  # py2
+
+    eos = property(lambda x: not x, doc="Are we at the end of the stream?")
+
+    def push(self, token):
+        """Push a token back to the stream."""
+        self._pushed.append(token)
+
+    def look(self):
+        """Look at the next token."""
+        old_token = next(self)
+        result = self.current
+        self.push(result)
+        self.current = old_token
+        return result
+
+    def skip(self, n=1):
+        """Got n tokens ahead."""
+        for x in range(n):
+            next(self)
+
+    def next_if(self, expr):
+        """Perform the token test and return the token if it matched.
+        Otherwise the return value is `None`.
+        """
+        if self.current.test(expr):
+            return next(self)
+
+    def skip_if(self, expr):
+        """Like :meth:`next_if` but only returns `True` or `False`."""
+        return self.next_if(expr) is not None
+
+    def __next__(self):
+        """Go one token ahead and return the old one.
+
+        Use the built-in :func:`next` instead of calling this directly.
+        """
+        rv = self.current
+        if self._pushed:
+            self.current = self._pushed.popleft()
+        elif self.current.type is not TOKEN_EOF:
+            try:
+                self.current = next(self._iter)
+            except StopIteration:
+                self.close()
+        return rv
+
+    def close(self):
+        """Close the stream."""
+        self.current = Token(self.current.lineno, TOKEN_EOF, '')
+        self._iter = None
+        self.closed = True
+
+    def expect(self, expr):
+        """Expect a given token type and return it.  This accepts the same
+        argument as :meth:`jinja2.lexer.Token.test`.
+        """
+        if not self.current.test(expr):
+            expr = describe_token_expr(expr)
+            if self.current.type is TOKEN_EOF:
+                raise TemplateSyntaxError('unexpected end of template, '
+                                          'expected %r.' % expr,
+                                          self.current.lineno,
+                                          self.name, self.filename)
+            raise TemplateSyntaxError("expected token %r, got %r" %
+                                      (expr, describe_token(self.current)),
+                                      self.current.lineno,
+                                      self.name, self.filename)
+        try:
+            return self.current
+        finally:
+            next(self)
+
+
+def get_lexer(environment):
+    """Return a lexer which is probably cached."""
+    key = (environment.block_start_string,
+           environment.block_end_string,
+           environment.variable_start_string,
+           environment.variable_end_string,
+           environment.comment_start_string,
+           environment.comment_end_string,
+           environment.line_statement_prefix,
+           environment.line_comment_prefix,
+           environment.trim_blocks,
+           environment.lstrip_blocks,
+           environment.newline_sequence,
+           environment.keep_trailing_newline)
+    lexer = _lexer_cache.get(key)
+    if lexer is None:
+        lexer = Lexer(environment)
+        _lexer_cache[key] = lexer
+    return lexer
+
+
+class Lexer(object):
+    """Class that implements a lexer for a given environment. Automatically
+    created by the environment class, usually you don't have to do that.
+
+    Note that the lexer is not automatically bound to an environment.
+    Multiple environments can share the same lexer.
+    """
+
+    def __init__(self, environment):
+        # shortcuts
+        c = lambda x: re.compile(x, re.M | re.S)
+        e = re.escape
+
+        # lexing rules for tags
+        tag_rules = [
+            (whitespace_re, TOKEN_WHITESPACE, None),
+            (float_re, TOKEN_FLOAT, None),
+            (integer_re, TOKEN_INTEGER, None),
+            (name_re, TOKEN_NAME, None),
+            (string_re, TOKEN_STRING, None),
+            (operator_re, TOKEN_OPERATOR, None)
+        ]
+
+        # assemble the root lexing rule. because "|" is ungreedy
+        # we have to sort by length so that the lexer continues working
+        # as expected when we have parsing rules like <% for block and
+        # <%= for variables. (if someone wants asp like syntax)
+        # variables are just part of the rules if variable processing
+        # is required.
+        root_tag_rules = compile_rules(environment)
+
+        # block suffix if trimming is enabled
+        block_suffix_re = environment.trim_blocks and '\\n?' or ''
+
+        # strip leading spaces if lstrip_blocks is enabled
+        prefix_re = {}
+        if environment.lstrip_blocks:
+            # use '{%+' to manually disable lstrip_blocks behavior
+            no_lstrip_re = e('+')
+            # detect overlap between block and variable or comment strings
+            block_diff = c(r'^%s(.*)' % e(environment.block_start_string))
+            # make sure we don't mistake a block for a variable or a comment
+            m = block_diff.match(environment.comment_start_string)
+            no_lstrip_re += m and r'|%s' % e(m.group(1)) or ''
+            m = block_diff.match(environment.variable_start_string)
+            no_lstrip_re += m and r'|%s' % e(m.group(1)) or ''
+
+            # detect overlap between comment and variable strings
+            comment_diff = c(r'^%s(.*)' % e(environment.comment_start_string))
+            m = comment_diff.match(environment.variable_start_string)
+            no_variable_re = m and r'(?!%s)' % e(m.group(1)) or ''
+
+            lstrip_re = r'^[ \t]*'
+            block_prefix_re = r'%s%s(?!%s)|%s\+?' % (
+                    lstrip_re,
+                    e(environment.block_start_string),
+                    no_lstrip_re,
+                    e(environment.block_start_string),
+                    )
+            comment_prefix_re = r'%s%s%s|%s\+?' % (
+                    lstrip_re,
+                    e(environment.comment_start_string),
+                    no_variable_re,
+                    e(environment.comment_start_string),
+                    )
+            prefix_re['block'] = block_prefix_re
+            prefix_re['comment'] = comment_prefix_re
+        else:
+            block_prefix_re = '%s' % e(environment.block_start_string)
+
+        self.newline_sequence = environment.newline_sequence
+        self.keep_trailing_newline = environment.keep_trailing_newline
+
+        # global lexing rules
+        self.rules = {
+            'root': [
+                # directives
+                (c('(.*?)(?:%s)' % '|'.join(
+                    [r'(?P<raw_begin>(?:\s*%s\-|%s)\s*raw\s*(?:\-%s\s*|%s))' % (
+                        e(environment.block_start_string),
+                        block_prefix_re,
+                        e(environment.block_end_string),
+                        e(environment.block_end_string)
+                    )] + [
+                        r'(?P<%s_begin>\s*%s\-|%s)' % (n, r, prefix_re.get(n,r))
+                        for n, r in root_tag_rules
+                    ])), (TOKEN_DATA, '#bygroup'), '#bygroup'),
+                # data
+                (c('.+'), TOKEN_DATA, None)
+            ],
+            # comments
+            TOKEN_COMMENT_BEGIN: [
+                (c(r'(.*?)((?:\-%s\s*|%s)%s)' % (
+                    e(environment.comment_end_string),
+                    e(environment.comment_end_string),
+                    block_suffix_re
+                )), (TOKEN_COMMENT, TOKEN_COMMENT_END), '#pop'),
+                (c('(.)'), (Failure('Missing end of comment tag'),), None)
+            ],
+            # blocks
+            TOKEN_BLOCK_BEGIN: [
+                (c(r'(?:\-%s\s*|%s)%s' % (
+                    e(environment.block_end_string),
+                    e(environment.block_end_string),
+                    block_suffix_re
+                )), TOKEN_BLOCK_END, '#pop'),
+            ] + tag_rules,
+            # variables
+            TOKEN_VARIABLE_BEGIN: [
+                (c(r'\-%s\s*|%s' % (
+                    e(environment.variable_end_string),
+                    e(environment.variable_end_string)
+                )), TOKEN_VARIABLE_END, '#pop')
+            ] + tag_rules,
+            # raw block
+            TOKEN_RAW_BEGIN: [
+                (c(r'(.*?)((?:\s*%s\-|%s)\s*endraw\s*(?:\-%s\s*|%s%s))' % (
+                    e(environment.block_start_string),
+                    block_prefix_re,
+                    e(environment.block_end_string),
+                    e(environment.block_end_string),
+                    block_suffix_re
+                )), (TOKEN_DATA, TOKEN_RAW_END), '#pop'),
+                (c('(.)'), (Failure('Missing end of raw directive'),), None)
+            ],
+            # line statements
+            TOKEN_LINESTATEMENT_BEGIN: [
+                (c(r'\s*(\n|$)'), TOKEN_LINESTATEMENT_END, '#pop')
+            ] + tag_rules,
+            # line comments
+            TOKEN_LINECOMMENT_BEGIN: [
+                (c(r'(.*?)()(?=\n|$)'), (TOKEN_LINECOMMENT,
+                 TOKEN_LINECOMMENT_END), '#pop')
+            ]
+        }
+
+    def _normalize_newlines(self, value):
+        """Called for strings and template data to normalize it to unicode."""
+        return newline_re.sub(self.newline_sequence, value)
+
+    def tokenize(self, source, name=None, filename=None, state=None):
+        """Calls tokeniter + tokenize and wraps it in a token stream.
+        """
+        stream = self.tokeniter(source, name, filename, state)
+        return TokenStream(self.wrap(stream, name, filename), name, filename)
+
+    def wrap(self, stream, name=None, filename=None):
+        """This is called with the stream as returned by `tokenize` and wraps
+        every token in a :class:`Token` and converts the value.
+        """
+        for lineno, token, value in stream:
+            if token in ignored_tokens:
+                continue
+            elif token == 'linestatement_begin':
+                token = 'block_begin'
+            elif token == 'linestatement_end':
+                token = 'block_end'
+            # we are not interested in those tokens in the parser
+            elif token in ('raw_begin', 'raw_end'):
+                continue
+            elif token == 'data':
+                value = self._normalize_newlines(value)
+            elif token == 'keyword':
+                token = value
+            elif token == 'name':
+                value = str(value)
+                if check_ident and not value.isidentifier():
+                    raise TemplateSyntaxError(
+                        'Invalid character in identifier',
+                        lineno, name, filename)
+            elif token == 'string':
+                # try to unescape string
+                try:
+                    value = self._normalize_newlines(value[1:-1]) \
+                        .encode('ascii', 'backslashreplace') \
+                        .decode('unicode-escape')
+                except Exception as e:
+                    msg = str(e).split(':')[-1].strip()
+                    raise TemplateSyntaxError(msg, lineno, name, filename)
+            elif token == 'integer':
+                value = int(value)
+            elif token == 'float':
+                value = float(value)
+            elif token == 'operator':
+                token = operators[value]
+            yield Token(lineno, token, value)
+
+    def tokeniter(self, source, name, filename=None, state=None):
+        """This method tokenizes the text and returns the tokens in a
+        generator.  Use this method if you just want to tokenize a template.
+        """
+        source = text_type(source)
+        lines = source.splitlines()
+        if self.keep_trailing_newline and source:
+            for newline in ('\r\n', '\r', '\n'):
+                if source.endswith(newline):
+                    lines.append('')
+                    break
+        source = '\n'.join(lines)
+        pos = 0
+        lineno = 1
+        stack = ['root']
+        if state is not None and state != 'root':
+            assert state in ('variable', 'block'), 'invalid state'
+            stack.append(state + '_begin')
+        else:
+            state = 'root'
+        statetokens = self.rules[stack[-1]]
+        source_length = len(source)
+
+        balancing_stack = []
+
+        while 1:
+            # tokenizer loop
+            for regex, tokens, new_state in statetokens:
+                m = regex.match(source, pos)
+                # if no match we try again with the next rule
+                if m is None:
+                    continue
+
+                # we only match blocks and variables if braces / parentheses
+                # are balanced. continue parsing with the lower rule which
+                # is the operator rule. do this only if the end tags look
+                # like operators
+                if balancing_stack and \
+                   tokens in ('variable_end', 'block_end',
+                              'linestatement_end'):
+                    continue
+
+                # tuples support more options
+                if isinstance(tokens, tuple):
+                    for idx, token in enumerate(tokens):
+                        # failure group
+                        if token.__class__ is Failure:
+                            raise token(lineno, filename)
+                        # bygroup is a bit more complex, in that case we
+                        # yield for the current token the first named
+                        # group that matched
+                        elif token == '#bygroup':
+                            for key, value in iteritems(m.groupdict()):
+                                if value is not None:
+                                    yield lineno, key, value
+                                    lineno += value.count('\n')
+                                    break
+                            else:
+                                raise RuntimeError('%r wanted to resolve '
+                                                   'the token dynamically'
+                                                   ' but no group matched'
+                                                   % regex)
+                        # normal group
+                        else:
+                            data = m.group(idx + 1)
+                            if data or token not in ignore_if_empty:
+                                yield lineno, token, data
+                            lineno += data.count('\n')
+
+                # strings as token just are yielded as it.
+                else:
+                    data = m.group()
+                    # update brace/parentheses balance
+                    if tokens == 'operator':
+                        if data == '{':
+                            balancing_stack.append('}')
+                        elif data == '(':
+                            balancing_stack.append(')')
+                        elif data == '[':
+                            balancing_stack.append(']')
+                        elif data in ('}', ')', ']'):
+                            if not balancing_stack:
+                                raise TemplateSyntaxError('unexpected \'%s\'' %
+                                                          data, lineno, name,
+                                                          filename)
+                            expected_op = balancing_stack.pop()
+                            if expected_op != data:
+                                raise TemplateSyntaxError('unexpected \'%s\', '
+                                                          'expected \'%s\'' %
+                                                          (data, expected_op),
+                                                          lineno, name,
+                                                          filename)
+                    # yield items
+                    if data or tokens not in ignore_if_empty:
+                        yield lineno, tokens, data
+                    lineno += data.count('\n')
+
+                # fetch new position into new variable so that we can check
+                # if there is a internal parsing error which would result
+                # in an infinite loop
+                pos2 = m.end()
+
+                # handle state changes
+                if new_state is not None:
+                    # remove the uppermost state
+                    if new_state == '#pop':
+                        stack.pop()
+                    # resolve the new state by group checking
+                    elif new_state == '#bygroup':
+                        for key, value in iteritems(m.groupdict()):
+                            if value is not None:
+                                stack.append(key)
+                                break
+                        else:
+                            raise RuntimeError('%r wanted to resolve the '
+                                               'new state dynamically but'
+                                               ' no group matched' %
+                                               regex)
+                    # direct state name given
+                    else:
+                        stack.append(new_state)
+                    statetokens = self.rules[stack[-1]]
+                # we are still at the same position and no stack change.
+                # this means a loop without break condition, avoid that and
+                # raise error
+                elif pos2 == pos:
+                    raise RuntimeError('%r yielded empty string without '
+                                       'stack change' % regex)
+                # publish new function and start again
+                pos = pos2
+                break
+            # if loop terminated without break we haven't found a single match
+            # either we are at the end of the file or we have a problem
+            else:
+                # end of text
+                if pos >= source_length:
+                    return
+                # something went wrong
+                raise TemplateSyntaxError('unexpected char %r at %d' %
+                                          (source[pos], pos), lineno,
+                                          name, filename)

cement/cli/contrib/jinja2/loaders.py

@@ -0,0 +1,481 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.loaders
+    ~~~~~~~~~~~~~~
+
+    Jinja loader classes.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import os
+import sys
+import weakref
+from types import ModuleType
+from os import path
+from hashlib import sha1
+from jinja2.exceptions import TemplateNotFound
+from jinja2.utils import open_if_exists, internalcode
+from jinja2._compat import string_types, iteritems
+
+
+def split_template_path(template):
+    """Split a path into segments and perform a sanity check.  If it detects
+    '..' in the path it will raise a `TemplateNotFound` error.
+    """
+    pieces = []
+    for piece in template.split('/'):
+        if path.sep in piece \
+           or (path.altsep and path.altsep in piece) or \
+           piece == path.pardir:
+            raise TemplateNotFound(template)
+        elif piece and piece != '.':
+            pieces.append(piece)
+    return pieces
+
+
+class BaseLoader(object):
+    """Baseclass for all loaders.  Subclass this and override `get_source` to
+    implement a custom loading mechanism.  The environment provides a
+    `get_template` method that calls the loader's `load` method to get the
+    :class:`Template` object.
+
+    A very basic example for a loader that looks up templates on the file
+    system could look like this::
+
+        from jinja2 import BaseLoader, TemplateNotFound
+        from os.path import join, exists, getmtime
+
+        class MyLoader(BaseLoader):
+
+            def __init__(self, path):
+                self.path = path
+
+            def get_source(self, environment, template):
+                path = join(self.path, template)
+                if not exists(path):
+                    raise TemplateNotFound(template)
+                mtime = getmtime(path)
+                with file(path) as f:
+                    source = f.read().decode('utf-8')
+                return source, path, lambda: mtime == getmtime(path)
+    """
+
+    #: if set to `False` it indicates that the loader cannot provide access
+    #: to the source of templates.
+    #:
+    #: .. versionadded:: 2.4
+    has_source_access = True
+
+    def get_source(self, environment, template):
+        """Get the template source, filename and reload helper for a template.
+        It's passed the environment and template name and has to return a
+        tuple in the form ``(source, filename, uptodate)`` or raise a
+        `TemplateNotFound` error if it can't locate the template.
+
+        The source part of the returned tuple must be the source of the
+        template as unicode string or a ASCII bytestring.  The filename should
+        be the name of the file on the filesystem if it was loaded from there,
+        otherwise `None`.  The filename is used by python for the tracebacks
+        if no loader extension is used.
+
+        The last item in the tuple is the `uptodate` function.  If auto
+        reloading is enabled it's always called to check if the template
+        changed.  No arguments are passed so the function must store the
+        old state somewhere (for example in a closure).  If it returns `False`
+        the template will be reloaded.
+        """
+        if not self.has_source_access:
+            raise RuntimeError('%s cannot provide access to the source' %
+                               self.__class__.__name__)
+        raise TemplateNotFound(template)
+
+    def list_templates(self):
+        """Iterates over all templates.  If the loader does not support that
+        it should raise a :exc:`TypeError` which is the default behavior.
+        """
+        raise TypeError('this loader cannot iterate over all templates')
+
+    @internalcode
+    def load(self, environment, name, globals=None):
+        """Loads a template.  This method looks up the template in the cache
+        or loads one by calling :meth:`get_source`.  Subclasses should not
+        override this method as loaders working on collections of other
+        loaders (such as :class:`PrefixLoader` or :class:`ChoiceLoader`)
+        will not call this method but `get_source` directly.
+        """
+        code = None
+        if globals is None:
+            globals = {}
+
+        # first we try to get the source for this template together
+        # with the filename and the uptodate function.
+        source, filename, uptodate = self.get_source(environment, name)
+
+        # try to load the code from the bytecode cache if there is a
+        # bytecode cache configured.
+        bcc = environment.bytecode_cache
+        if bcc is not None:
+            bucket = bcc.get_bucket(environment, name, filename, source)
+            code = bucket.code
+
+        # if we don't have code so far (not cached, no longer up to
+        # date) etc. we compile the template
+        if code is None:
+            code = environment.compile(source, name, filename)
+
+        # if the bytecode cache is available and the bucket doesn't
+        # have a code so far, we give the bucket the new code and put
+        # it back to the bytecode cache.
+        if bcc is not None and bucket.code is None:
+            bucket.code = code
+            bcc.set_bucket(bucket)
+
+        return environment.template_class.from_code(environment, code,
+                                                    globals, uptodate)
+
+
+class FileSystemLoader(BaseLoader):
+    """Loads templates from the file system.  This loader can find templates
+    in folders on the file system and is the preferred way to load them.
+
+    The loader takes the path to the templates as string, or if multiple
+    locations are wanted a list of them which is then looked up in the
+    given order::
+
+    >>> loader = FileSystemLoader('/path/to/templates')
+    >>> loader = FileSystemLoader(['/path/to/templates', '/other/path'])
+
+    Per default the template encoding is ``'utf-8'`` which can be changed
+    by setting the `encoding` parameter to something else.
+
+    To follow symbolic links, set the *followlinks* parameter to ``True``::
+
+    >>> loader = FileSystemLoader('/path/to/templates', followlinks=True)
+
+    .. versionchanged:: 2.8+
+       The *followlinks* parameter was added.
+    """
+
+    def __init__(self, searchpath, encoding='utf-8', followlinks=False):
+        if isinstance(searchpath, string_types):
+            searchpath = [searchpath]
+        self.searchpath = list(searchpath)
+        self.encoding = encoding
+        self.followlinks = followlinks
+
+    def get_source(self, environment, template):
+        pieces = split_template_path(template)
+        for searchpath in self.searchpath:
+            filename = path.join(searchpath, *pieces)
+            f = open_if_exists(filename)
+            if f is None:
+                continue
+            try:
+                contents = f.read().decode(self.encoding)
+            finally:
+                f.close()
+
+            mtime = path.getmtime(filename)
+
+            def uptodate():
+                try:
+                    return path.getmtime(filename) == mtime
+                except OSError:
+                    return False
+            return contents, filename, uptodate
+        raise TemplateNotFound(template)
+
+    def list_templates(self):
+        found = set()
+        for searchpath in self.searchpath:
+            walk_dir = os.walk(searchpath, followlinks=self.followlinks)
+            for dirpath, dirnames, filenames in walk_dir:
+                for filename in filenames:
+                    template = os.path.join(dirpath, filename) \
+                        [len(searchpath):].strip(os.path.sep) \
+                                          .replace(os.path.sep, '/')
+                    if template[:2] == './':
+                        template = template[2:]
+                    if template not in found:
+                        found.add(template)
+        return sorted(found)
+
+
+class PackageLoader(BaseLoader):
+    """Load templates from python eggs or packages.  It is constructed with
+    the name of the python package and the path to the templates in that
+    package::
+
+        loader = PackageLoader('mypackage', 'views')
+
+    If the package path is not given, ``'templates'`` is assumed.
+
+    Per default the template encoding is ``'utf-8'`` which can be changed
+    by setting the `encoding` parameter to something else.  Due to the nature
+    of eggs it's only possible to reload templates if the package was loaded
+    from the file system and not a zip file.
+    """
+
+    def __init__(self, package_name, package_path='templates',
+                 encoding='utf-8'):
+        from pkg_resources import DefaultProvider, ResourceManager, \
+                                  get_provider
+        provider = get_provider(package_name)
+        self.encoding = encoding
+        self.manager = ResourceManager()
+        self.filesystem_bound = isinstance(provider, DefaultProvider)
+        self.provider = provider
+        self.package_path = package_path
+
+    def get_source(self, environment, template):
+        pieces = split_template_path(template)
+        p = '/'.join((self.package_path,) + tuple(pieces))
+        if not self.provider.has_resource(p):
+            raise TemplateNotFound(template)
+
+        filename = uptodate = None
+        if self.filesystem_bound:
+            filename = self.provider.get_resource_filename(self.manager, p)
+            mtime = path.getmtime(filename)
+            def uptodate():
+                try:
+                    return path.getmtime(filename) == mtime
+                except OSError:
+                    return False
+
+        source = self.provider.get_resource_string(self.manager, p)
+        return source.decode(self.encoding), filename, uptodate
+
+    def list_templates(self):
+        path = self.package_path
+        if path[:2] == './':
+            path = path[2:]
+        elif path == '.':
+            path = ''
+        offset = len(path)
+        results = []
+        def _walk(path):
+            for filename in self.provider.resource_listdir(path):
+                fullname = path + '/' + filename
+                if self.provider.resource_isdir(fullname):
+                    _walk(fullname)
+                else:
+                    results.append(fullname[offset:].lstrip('/'))
+        _walk(path)
+        results.sort()
+        return results
+
+
+class DictLoader(BaseLoader):
+    """Loads a template from a python dict.  It's passed a dict of unicode
+    strings bound to template names.  This loader is useful for unittesting:
+
+    >>> loader = DictLoader({'index.html': 'source here'})
+
+    Because auto reloading is rarely useful this is disabled per default.
+    """
+
+    def __init__(self, mapping):
+        self.mapping = mapping
+
+    def get_source(self, environment, template):
+        if template in self.mapping:
+            source = self.mapping[template]
+            return source, None, lambda: source == self.mapping.get(template)
+        raise TemplateNotFound(template)
+
+    def list_templates(self):
+        return sorted(self.mapping)
+
+
+class FunctionLoader(BaseLoader):
+    """A loader that is passed a function which does the loading.  The
+    function receives the name of the template and has to return either
+    an unicode string with the template source, a tuple in the form ``(source,
+    filename, uptodatefunc)`` or `None` if the template does not exist.
+
+    >>> def load_template(name):
+    ...     if name == 'index.html':
+    ...         return '...'
+    ...
+    >>> loader = FunctionLoader(load_template)
+
+    The `uptodatefunc` is a function that is called if autoreload is enabled
+    and has to return `True` if the template is still up to date.  For more
+    details have a look at :meth:`BaseLoader.get_source` which has the same
+    return value.
+    """
+
+    def __init__(self, load_func):
+        self.load_func = load_func
+
+    def get_source(self, environment, template):
+        rv = self.load_func(template)
+        if rv is None:
+            raise TemplateNotFound(template)
+        elif isinstance(rv, string_types):
+            return rv, None, None
+        return rv
+
+
+class PrefixLoader(BaseLoader):
+    """A loader that is passed a dict of loaders where each loader is bound
+    to a prefix.  The prefix is delimited from the template by a slash per
+    default, which can be changed by setting the `delimiter` argument to
+    something else::
+
+        loader = PrefixLoader({
+            'app1':     PackageLoader('mypackage.app1'),
+            'app2':     PackageLoader('mypackage.app2')
+        })
+
+    By loading ``'app1/index.html'`` the file from the app1 package is loaded,
+    by loading ``'app2/index.html'`` the file from the second.
+    """
+
+    def __init__(self, mapping, delimiter='/'):
+        self.mapping = mapping
+        self.delimiter = delimiter
+
+    def get_loader(self, template):
+        try:
+            prefix, name = template.split(self.delimiter, 1)
+            loader = self.mapping[prefix]
+        except (ValueError, KeyError):
+            raise TemplateNotFound(template)
+        return loader, name
+
+    def get_source(self, environment, template):
+        loader, name = self.get_loader(template)
+        try:
+            return loader.get_source(environment, name)
+        except TemplateNotFound:
+            # re-raise the exception with the correct filename here.
+            # (the one that includes the prefix)
+            raise TemplateNotFound(template)
+
+    @internalcode
+    def load(self, environment, name, globals=None):
+        loader, local_name = self.get_loader(name)
+        try:
+            return loader.load(environment, local_name, globals)
+        except TemplateNotFound:
+            # re-raise the exception with the correct filename here.
+            # (the one that includes the prefix)
+            raise TemplateNotFound(name)
+
+    def list_templates(self):
+        result = []
+        for prefix, loader in iteritems(self.mapping):
+            for template in loader.list_templates():
+                result.append(prefix + self.delimiter + template)
+        return result
+
+
+class ChoiceLoader(BaseLoader):
+    """This loader works like the `PrefixLoader` just that no prefix is
+    specified.  If a template could not be found by one loader the next one
+    is tried.
+
+    >>> loader = ChoiceLoader([
+    ...     FileSystemLoader('/path/to/user/templates'),
+    ...     FileSystemLoader('/path/to/system/templates')
+    ... ])
+
+    This is useful if you want to allow users to override builtin templates
+    from a different location.
+    """
+
+    def __init__(self, loaders):
+        self.loaders = loaders
+
+    def get_source(self, environment, template):
+        for loader in self.loaders:
+            try:
+                return loader.get_source(environment, template)
+            except TemplateNotFound:
+                pass
+        raise TemplateNotFound(template)
+
+    @internalcode
+    def load(self, environment, name, globals=None):
+        for loader in self.loaders:
+            try:
+                return loader.load(environment, name, globals)
+            except TemplateNotFound:
+                pass
+        raise TemplateNotFound(name)
+
+    def list_templates(self):
+        found = set()
+        for loader in self.loaders:
+            found.update(loader.list_templates())
+        return sorted(found)
+
+
+class _TemplateModule(ModuleType):
+    """Like a normal module but with support for weak references"""
+
+
+class ModuleLoader(BaseLoader):
+    """This loader loads templates from precompiled templates.
+
+    Example usage:
+
+    >>> loader = ChoiceLoader([
+    ...     ModuleLoader('/path/to/compiled/templates'),
+    ...     FileSystemLoader('/path/to/templates')
+    ... ])
+
+    Templates can be precompiled with :meth:`Environment.compile_templates`.
+    """
+
+    has_source_access = False
+
+    def __init__(self, path):
+        package_name = '_jinja2_module_templates_%x' % id(self)
+
+        # create a fake module that looks for the templates in the
+        # path given.
+        mod = _TemplateModule(package_name)
+        if isinstance(path, string_types):
+            path = [path]
+        else:
+            path = list(path)
+        mod.__path__ = path
+
+        sys.modules[package_name] = weakref.proxy(mod,
+            lambda x: sys.modules.pop(package_name, None))
+
+        # the only strong reference, the sys.modules entry is weak
+        # so that the garbage collector can remove it once the
+        # loader that created it goes out of business.
+        self.module = mod
+        self.package_name = package_name
+
+    @staticmethod
+    def get_template_key(name):
+        return 'tmpl_' + sha1(name.encode('utf-8')).hexdigest()
+
+    @staticmethod
+    def get_module_filename(name):
+        return ModuleLoader.get_template_key(name) + '.py'
+
+    @internalcode
+    def load(self, environment, name, globals=None):
+        key = self.get_template_key(name)
+        module = '%s.%s' % (self.package_name, key)
+        mod = getattr(self.module, module, None)
+        if mod is None:
+            try:
+                mod = __import__(module, None, None, ['root'])
+            except ImportError:
+                raise TemplateNotFound(name)
+
+            # remove the entry from sys.modules, we only want the attribute
+            # on the module object we have stored on the loader.
+            sys.modules.pop(module, None)
+
+        return environment.template_class.from_module_dict(
+            environment, mod.__dict__, globals)

cement/cli/contrib/jinja2/meta.py

@@ -0,0 +1,106 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.meta
+    ~~~~~~~~~~~
+
+    This module implements various functions that exposes information about
+    templates that might be interesting for various kinds of applications.
+
+    :copyright: (c) 2017 by the Jinja Team, see AUTHORS for more details.
+    :license: BSD, see LICENSE for more details.
+"""
+from jinja2 import nodes
+from jinja2.compiler import CodeGenerator
+from jinja2._compat import string_types, iteritems
+
+
+class TrackingCodeGenerator(CodeGenerator):
+    """We abuse the code generator for introspection."""
+
+    def __init__(self, environment):
+        CodeGenerator.__init__(self, environment, '<introspection>',
+                               '<introspection>')
+        self.undeclared_identifiers = set()
+
+    def write(self, x):
+        """Don't write."""
+
+    def enter_frame(self, frame):
+        """Remember all undeclared identifiers."""
+        CodeGenerator.enter_frame(self, frame)
+        for _, (action, param) in iteritems(frame.symbols.loads):
+            if action == 'resolve':
+                self.undeclared_identifiers.add(param)
+
+
+def find_undeclared_variables(ast):
+    """Returns a set of all variables in the AST that will be looked up from
+    the context at runtime.  Because at compile time it's not known which
+    variables will be used depending on the path the execution takes at
+    runtime, all variables are returned.
+
+    >>> from jinja2 import Environment, meta
+    >>> env = Environment()
+    >>> ast = env.parse('{% set foo = 42 %}{{ bar + foo }}')
+    >>> meta.find_undeclared_variables(ast) == set(['bar'])
+    True
+
+    .. admonition:: Implementation
+
+       Internally the code generator is used for finding undeclared variables.
+       This is good to know because the code generator might raise a
+       :exc:`TemplateAssertionError` during compilation and as a matter of
+       fact this function can currently raise that exception as well.
+    """
+    codegen = TrackingCodeGenerator(ast.environment)
+    codegen.visit(ast)
+    return codegen.undeclared_identifiers
+
+
+def find_referenced_templates(ast):
+    """Finds all the referenced templates from the AST.  This will return an
+    iterator over all the hardcoded template extensions, inclusions and
+    imports.  If dynamic inheritance or inclusion is used, `None` will be
+    yielded.
+
+    >>> from jinja2 import Environment, meta
+    >>> env = Environment()
+    >>> ast = env.parse('{% extends "layout.html" %}{% include helper %}')
+    >>> list(meta.find_referenced_templates(ast))
+    ['layout.html', None]
+
+    This function is useful for dependency tracking.  For example if you want
+    to rebuild parts of the website after a layout template has changed.
+    """
+    for node in ast.find_all((nodes.Extends, nodes.FromImport, nodes.Import,
+                              nodes.Include)):
+        if not isinstance(node.template, nodes.Const):
+            # a tuple with some non consts in there
+            if isinstance(node.template, (nodes.Tuple, nodes.List)):
+                for template_name in node.template.items:
+                    # something const, only yield the strings and ignore
+                    # non-string consts that really just make no sense
+                    if isinstance(template_name, nodes.Const):
+                        if isinstance(template_name.value, string_types):
+                            yield template_name.value
+                    # something dynamic in there
+                    else:
+                        yield None
+            # something dynamic we don't know about here
+            else:
+                yield None
+            continue
+        # constant is a basestring, direct template name
+        if isinstance(node.template.value, string_types):
+            yield node.template.value
+        # a tuple or list (latter *should* not happen) made of consts,
+        # yield the consts that are strings.  We could warn here for
+        # non string values
+        elif isinstance(node, nodes.Include) and \
+             isinstance(node.template.value, (tuple, list)):
+            for template_name in node.template.value:
+                if isinstance(template_name, string_types):
+                    yield template_name
+        # something else we don't care about, we could warn here
+        else:
+            yield None

cement/cli/contrib/jinja2/nativetypes.py

@@ -0,0 +1,220 @@
+import sys
+from ast import literal_eval
+from itertools import islice, chain
+from jinja2 import nodes
+from jinja2._compat import text_type
+from jinja2.compiler import CodeGenerator, has_safe_repr
+from jinja2.environment import Environment, Template
+from jinja2.utils import concat, escape
+
+
+def native_concat(nodes):
+    """Return a native Python type from the list of compiled nodes. If the
+    result is a single node, its value is returned. Otherwise, the nodes are
+    concatenated as strings. If the result can be parsed with
+    :func:`ast.literal_eval`, the parsed value is returned. Otherwise, the
+    string is returned.
+    """
+    head = list(islice(nodes, 2))
+
+    if not head:
+        return None
+
+    if len(head) == 1:
+        out = head[0]
+    else:
+        out = u''.join([text_type(v) for v in chain(head, nodes)])
+
+    try:
+        return literal_eval(out)
+    except (ValueError, SyntaxError, MemoryError):
+        return out
+
+
+class NativeCodeGenerator(CodeGenerator):
+    """A code generator which avoids injecting ``to_string()`` calls around the
+    internal code Jinja uses to render templates.
+    """
+
+    def visit_Output(self, node, frame):
+        """Same as :meth:`CodeGenerator.visit_Output`, but do not call
+        ``to_string`` on output nodes in generated code.
+        """
+        if self.has_known_extends and frame.require_output_check:
+            return
+
+        finalize = self.environment.finalize
+        finalize_context = getattr(finalize, 'contextfunction', False)
+        finalize_eval = getattr(finalize, 'evalcontextfunction', False)
+        finalize_env = getattr(finalize, 'environmentfunction', False)
+
+        if finalize is not None:
+            if finalize_context or finalize_eval:
+                const_finalize = None
+            elif finalize_env:
+                def const_finalize(x):
+                    return finalize(self.environment, x)
+            else:
+                const_finalize = finalize
+        else:
+            def const_finalize(x):
+                return x
+
+        # If we are inside a frame that requires output checking, we do so.
+        outdent_later = False
+
+        if frame.require_output_check:
+            self.writeline('if parent_template is None:')
+            self.indent()
+            outdent_later = True
+
+        # Try to evaluate as many chunks as possible into a static string at
+        # compile time.
+        body = []
+
+        for child in node.nodes:
+            try:
+                if const_finalize is None:
+                    raise nodes.Impossible()
+
+                const = child.as_const(frame.eval_ctx)
+                if not has_safe_repr(const):
+                    raise nodes.Impossible()
+            except nodes.Impossible:
+                body.append(child)
+                continue
+
+            # the frame can't be volatile here, because otherwise the as_const
+            # function would raise an Impossible exception at that point
+            try:
+                if frame.eval_ctx.autoescape:
+                    if hasattr(const, '__html__'):
+                        const = const.__html__()
+                    else:
+                        const = escape(const)
+
+                const = const_finalize(const)
+            except Exception:
+                # if something goes wrong here we evaluate the node at runtime
+                # for easier debugging
+                body.append(child)
+                continue
+
+            if body and isinstance(body[-1], list):
+                body[-1].append(const)
+            else:
+                body.append([const])
+
+        # if we have less than 3 nodes or a buffer we yield or extend/append
+        if len(body) < 3 or frame.buffer is not None:
+            if frame.buffer is not None:
+                # for one item we append, for more we extend
+                if len(body) == 1:
+                    self.writeline('%s.append(' % frame.buffer)
+                else:
+                    self.writeline('%s.extend((' % frame.buffer)
+
+                self.indent()
+
+            for item in body:
+                if isinstance(item, list):
+                    val = repr(native_concat(item))
+
+                    if frame.buffer is None:
+                        self.writeline('yield ' + val)
+                    else:
+                        self.writeline(val + ',')
+                else:
+                    if frame.buffer is None:
+                        self.writeline('yield ', item)
+                    else:
+                        self.newline(item)
+
+                    close = 0
+
+                    if finalize is not None:
+                        self.write('environment.finalize(')
+
+                        if finalize_context:
+                            self.write('context, ')
+
+                        close += 1
+
+                    self.visit(item, frame)
+
+                    if close > 0:
+                        self.write(')' * close)
+
+                    if frame.buffer is not None:
+                        self.write(',')
+
+            if frame.buffer is not None:
+                # close the open parentheses
+                self.outdent()
+                self.writeline(len(body) == 1 and ')' or '))')
+
+        # otherwise we create a format string as this is faster in that case
+        else:
+            format = []
+            arguments = []
+
+            for item in body:
+                if isinstance(item, list):
+                    format.append(native_concat(item).replace('%', '%%'))
+                else:
+                    format.append('%s')
+                    arguments.append(item)
+
+            self.writeline('yield ')
+            self.write(repr(concat(format)) + ' % (')
+            self.indent()
+
+            for argument in arguments:
+                self.newline(argument)
+                close = 0
+
+                if finalize is not None:
+                    self.write('environment.finalize(')
+
+                    if finalize_context:
+                        self.write('context, ')
+                    elif finalize_eval:
+                        self.write('context.eval_ctx, ')
+                    elif finalize_env:
+                        self.write('environment, ')
+
+                    close += 1
+
+                self.visit(argument, frame)
+                self.write(')' * close + ', ')
+
+            self.outdent()
+            self.writeline(')')
+
+        if outdent_later:
+            self.outdent()
+
+
+class NativeTemplate(Template):
+    def render(self, *args, **kwargs):
+        """Render the template to produce a native Python type. If the result
+        is a single node, its value is returned. Otherwise, the nodes are
+        concatenated as strings. If the result can be parsed with
+        :func:`ast.literal_eval`, the parsed value is returned. Otherwise, the
+        string is returned.
+        """
+        vars = dict(*args, **kwargs)
+
+        try:
+            return native_concat(self.root_render_func(self.new_context(vars)))
+        except Exception:
+            exc_info = sys.exc_info()
+
+        return self.environment.handle_exception(exc_info, True)
+
+
+class NativeEnvironment(Environment):
+    """An environment that renders templates to native Python types."""
+
+    code_generator_class = NativeCodeGenerator
+    template_class = NativeTemplate

cement/cli/contrib/jinja2/nodes.py

@@ -0,0 +1,999 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.nodes
+    ~~~~~~~~~~~~
+
+    This module implements additional nodes derived from the ast base node.
+
+    It also provides some node tree helper functions like `in_lineno` and
+    `get_nodes` used by the parser and translator in order to normalize
+    python and jinja nodes.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import types
+import operator
+
+from collections import deque
+from jinja2.utils import Markup
+from jinja2._compat import izip, with_metaclass, text_type, PY2
+
+
+#: the types we support for context functions
+_context_function_types = (types.FunctionType, types.MethodType)
+
+
+_binop_to_func = {
+    '*':        operator.mul,
+    '/':        operator.truediv,
+    '//':       operator.floordiv,
+    '**':       operator.pow,
+    '%':        operator.mod,
+    '+':        operator.add,
+    '-':        operator.sub
+}
+
+_uaop_to_func = {
+    'not':      operator.not_,
+    '+':        operator.pos,
+    '-':        operator.neg
+}
+
+_cmpop_to_func = {
+    'eq':       operator.eq,
+    'ne':       operator.ne,
+    'gt':       operator.gt,
+    'gteq':     operator.ge,
+    'lt':       operator.lt,
+    'lteq':     operator.le,
+    'in':       lambda a, b: a in b,
+    'notin':    lambda a, b: a not in b
+}
+
+
+class Impossible(Exception):
+    """Raised if the node could not perform a requested action."""
+
+
+class NodeType(type):
+    """A metaclass for nodes that handles the field and attribute
+    inheritance.  fields and attributes from the parent class are
+    automatically forwarded to the child."""
+
+    def __new__(cls, name, bases, d):
+        for attr in 'fields', 'attributes':
+            storage = []
+            storage.extend(getattr(bases[0], attr, ()))
+            storage.extend(d.get(attr, ()))
+            assert len(bases) == 1, 'multiple inheritance not allowed'
+            assert len(storage) == len(set(storage)), 'layout conflict'
+            d[attr] = tuple(storage)
+        d.setdefault('abstract', False)
+        return type.__new__(cls, name, bases, d)
+
+
+class EvalContext(object):
+    """Holds evaluation time information.  Custom attributes can be attached
+    to it in extensions.
+    """
+
+    def __init__(self, environment, template_name=None):
+        self.environment = environment
+        if callable(environment.autoescape):
+            self.autoescape = environment.autoescape(template_name)
+        else:
+            self.autoescape = environment.autoescape
+        self.volatile = False
+
+    def save(self):
+        return self.__dict__.copy()
+
+    def revert(self, old):
+        self.__dict__.clear()
+        self.__dict__.update(old)
+
+
+def get_eval_context(node, ctx):
+    if ctx is None:
+        if node.environment is None:
+            raise RuntimeError('if no eval context is passed, the '
+                               'node must have an attached '
+                               'environment.')
+        return EvalContext(node.environment)
+    return ctx
+
+
+class Node(with_metaclass(NodeType, object)):
+    """Baseclass for all Jinja2 nodes.  There are a number of nodes available
+    of different types.  There are four major types:
+
+    -   :class:`Stmt`: statements
+    -   :class:`Expr`: expressions
+    -   :class:`Helper`: helper nodes
+    -   :class:`Template`: the outermost wrapper node
+
+    All nodes have fields and attributes.  Fields may be other nodes, lists,
+    or arbitrary values.  Fields are passed to the constructor as regular
+    positional arguments, attributes as keyword arguments.  Each node has
+    two attributes: `lineno` (the line number of the node) and `environment`.
+    The `environment` attribute is set at the end of the parsing process for
+    all nodes automatically.
+    """
+    fields = ()
+    attributes = ('lineno', 'environment')
+    abstract = True
+
+    def __init__(self, *fields, **attributes):
+        if self.abstract:
+            raise TypeError('abstract nodes are not instanciable')
+        if fields:
+            if len(fields) != len(self.fields):
+                if not self.fields:
+                    raise TypeError('%r takes 0 arguments' %
+                                    self.__class__.__name__)
+                raise TypeError('%r takes 0 or %d argument%s' % (
+                    self.__class__.__name__,
+                    len(self.fields),
+                    len(self.fields) != 1 and 's' or ''
+                ))
+            for name, arg in izip(self.fields, fields):
+                setattr(self, name, arg)
+        for attr in self.attributes:
+            setattr(self, attr, attributes.pop(attr, None))
+        if attributes:
+            raise TypeError('unknown attribute %r' %
+                            next(iter(attributes)))
+
+    def iter_fields(self, exclude=None, only=None):
+        """This method iterates over all fields that are defined and yields
+        ``(key, value)`` tuples.  Per default all fields are returned, but
+        it's possible to limit that to some fields by providing the `only`
+        parameter or to exclude some using the `exclude` parameter.  Both
+        should be sets or tuples of field names.
+        """
+        for name in self.fields:
+            if (exclude is only is None) or \
+               (exclude is not None and name not in exclude) or \
+               (only is not None and name in only):
+                try:
+                    yield name, getattr(self, name)
+                except AttributeError:
+                    pass
+
+    def iter_child_nodes(self, exclude=None, only=None):
+        """Iterates over all direct child nodes of the node.  This iterates
+        over all fields and yields the values of they are nodes.  If the value
+        of a field is a list all the nodes in that list are returned.
+        """
+        for field, item in self.iter_fields(exclude, only):
+            if isinstance(item, list):
+                for n in item:
+                    if isinstance(n, Node):
+                        yield n
+            elif isinstance(item, Node):
+                yield item
+
+    def find(self, node_type):
+        """Find the first node of a given type.  If no such node exists the
+        return value is `None`.
+        """
+        for result in self.find_all(node_type):
+            return result
+
+    def find_all(self, node_type):
+        """Find all the nodes of a given type.  If the type is a tuple,
+        the check is performed for any of the tuple items.
+        """
+        for child in self.iter_child_nodes():
+            if isinstance(child, node_type):
+                yield child
+            for result in child.find_all(node_type):
+                yield result
+
+    def set_ctx(self, ctx):
+        """Reset the context of a node and all child nodes.  Per default the
+        parser will all generate nodes that have a 'load' context as it's the
+        most common one.  This method is used in the parser to set assignment
+        targets and other nodes to a store context.
+        """
+        todo = deque([self])
+        while todo:
+            node = todo.popleft()
+            if 'ctx' in node.fields:
+                node.ctx = ctx
+            todo.extend(node.iter_child_nodes())
+        return self
+
+    def set_lineno(self, lineno, override=False):
+        """Set the line numbers of the node and children."""
+        todo = deque([self])
+        while todo:
+            node = todo.popleft()
+            if 'lineno' in node.attributes:
+                if node.lineno is None or override:
+                    node.lineno = lineno
+            todo.extend(node.iter_child_nodes())
+        return self
+
+    def set_environment(self, environment):
+        """Set the environment for all nodes."""
+        todo = deque([self])
+        while todo:
+            node = todo.popleft()
+            node.environment = environment
+            todo.extend(node.iter_child_nodes())
+        return self
+
+    def __eq__(self, other):
+        return type(self) is type(other) and \
+               tuple(self.iter_fields()) == tuple(other.iter_fields())
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    # Restore Python 2 hashing behavior on Python 3
+    __hash__ = object.__hash__
+
+    def __repr__(self):
+        return '%s(%s)' % (
+            self.__class__.__name__,
+            ', '.join('%s=%r' % (arg, getattr(self, arg, None)) for
+                      arg in self.fields)
+        )
+
+    def dump(self):
+        def _dump(node):
+            if not isinstance(node, Node):
+                buf.append(repr(node))
+                return
+
+            buf.append('nodes.%s(' % node.__class__.__name__)
+            if not node.fields:
+                buf.append(')')
+                return
+            for idx, field in enumerate(node.fields):
+                if idx:
+                    buf.append(', ')
+                value = getattr(node, field)
+                if isinstance(value, list):
+                    buf.append('[')
+                    for idx, item in enumerate(value):
+                        if idx:
+                            buf.append(', ')
+                        _dump(item)
+                    buf.append(']')
+                else:
+                    _dump(value)
+            buf.append(')')
+        buf = []
+        _dump(self)
+        return ''.join(buf)
+
+
+
+class Stmt(Node):
+    """Base node for all statements."""
+    abstract = True
+
+
+class Helper(Node):
+    """Nodes that exist in a specific context only."""
+    abstract = True
+
+
+class Template(Node):
+    """Node that represents a template.  This must be the outermost node that
+    is passed to the compiler.
+    """
+    fields = ('body',)
+
+
+class Output(Stmt):
+    """A node that holds multiple expressions which are then printed out.
+    This is used both for the `print` statement and the regular template data.
+    """
+    fields = ('nodes',)
+
+
+class Extends(Stmt):
+    """Represents an extends statement."""
+    fields = ('template',)
+
+
+class For(Stmt):
+    """The for loop.  `target` is the target for the iteration (usually a
+    :class:`Name` or :class:`Tuple`), `iter` the iterable.  `body` is a list
+    of nodes that are used as loop-body, and `else_` a list of nodes for the
+    `else` block.  If no else node exists it has to be an empty list.
+
+    For filtered nodes an expression can be stored as `test`, otherwise `None`.
+    """
+    fields = ('target', 'iter', 'body', 'else_', 'test', 'recursive')
+
+
+class If(Stmt):
+    """If `test` is true, `body` is rendered, else `else_`."""
+    fields = ('test', 'body', 'elif_', 'else_')
+
+
+class Macro(Stmt):
+    """A macro definition.  `name` is the name of the macro, `args` a list of
+    arguments and `defaults` a list of defaults if there are any.  `body` is
+    a list of nodes for the macro body.
+    """
+    fields = ('name', 'args', 'defaults', 'body')
+
+
+class CallBlock(Stmt):
+    """Like a macro without a name but a call instead.  `call` is called with
+    the unnamed macro as `caller` argument this node holds.
+    """
+    fields = ('call', 'args', 'defaults', 'body')
+
+
+class FilterBlock(Stmt):
+    """Node for filter sections."""
+    fields = ('body', 'filter')
+
+
+class With(Stmt):
+    """Specific node for with statements.  In older versions of Jinja the
+    with statement was implemented on the base of the `Scope` node instead.
+
+    .. versionadded:: 2.9.3
+    """
+    fields = ('targets', 'values', 'body')
+
+
+class Block(Stmt):
+    """A node that represents a block."""
+    fields = ('name', 'body', 'scoped')
+
+
+class Include(Stmt):
+    """A node that represents the include tag."""
+    fields = ('template', 'with_context', 'ignore_missing')
+
+
+class Import(Stmt):
+    """A node that represents the import tag."""
+    fields = ('template', 'target', 'with_context')
+
+
+class FromImport(Stmt):
+    """A node that represents the from import tag.  It's important to not
+    pass unsafe names to the name attribute.  The compiler translates the
+    attribute lookups directly into getattr calls and does *not* use the
+    subscript callback of the interface.  As exported variables may not
+    start with double underscores (which the parser asserts) this is not a
+    problem for regular Jinja code, but if this node is used in an extension
+    extra care must be taken.
+
+    The list of names may contain tuples if aliases are wanted.
+    """
+    fields = ('template', 'names', 'with_context')
+
+
+class ExprStmt(Stmt):
+    """A statement that evaluates an expression and discards the result."""
+    fields = ('node',)
+
+
+class Assign(Stmt):
+    """Assigns an expression to a target."""
+    fields = ('target', 'node')
+
+
+class AssignBlock(Stmt):
+    """Assigns a block to a target."""
+    fields = ('target', 'filter', 'body')
+
+
+class Expr(Node):
+    """Baseclass for all expressions."""
+    abstract = True
+
+    def as_const(self, eval_ctx=None):
+        """Return the value of the expression as constant or raise
+        :exc:`Impossible` if this was not possible.
+
+        An :class:`EvalContext` can be provided, if none is given
+        a default context is created which requires the nodes to have
+        an attached environment.
+
+        .. versionchanged:: 2.4
+           the `eval_ctx` parameter was added.
+        """
+        raise Impossible()
+
+    def can_assign(self):
+        """Check if it's possible to assign something to this node."""
+        return False
+
+
+class BinExpr(Expr):
+    """Baseclass for all binary expressions."""
+    fields = ('left', 'right')
+    operator = None
+    abstract = True
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        # intercepted operators cannot be folded at compile time
+        if self.environment.sandboxed and \
+           self.operator in self.environment.intercepted_binops:
+            raise Impossible()
+        f = _binop_to_func[self.operator]
+        try:
+            return f(self.left.as_const(eval_ctx), self.right.as_const(eval_ctx))
+        except Exception:
+            raise Impossible()
+
+
+class UnaryExpr(Expr):
+    """Baseclass for all unary expressions."""
+    fields = ('node',)
+    operator = None
+    abstract = True
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        # intercepted operators cannot be folded at compile time
+        if self.environment.sandboxed and \
+           self.operator in self.environment.intercepted_unops:
+            raise Impossible()
+        f = _uaop_to_func[self.operator]
+        try:
+            return f(self.node.as_const(eval_ctx))
+        except Exception:
+            raise Impossible()
+
+
+class Name(Expr):
+    """Looks up a name or stores a value in a name.
+    The `ctx` of the node can be one of the following values:
+
+    -   `store`: store a value in the name
+    -   `load`: load that name
+    -   `param`: like `store` but if the name was defined as function parameter.
+    """
+    fields = ('name', 'ctx')
+
+    def can_assign(self):
+        return self.name not in ('true', 'false', 'none',
+                                 'True', 'False', 'None')
+
+
+class NSRef(Expr):
+    """Reference to a namespace value assignment"""
+    fields = ('name', 'attr')
+
+    def can_assign(self):
+        # We don't need any special checks here; NSRef assignments have a
+        # runtime check to ensure the target is a namespace object which will
+        # have been checked already as it is created using a normal assignment
+        # which goes through a `Name` node.
+        return True
+
+
+class Literal(Expr):
+    """Baseclass for literals."""
+    abstract = True
+
+
+class Const(Literal):
+    """All constant values.  The parser will return this node for simple
+    constants such as ``42`` or ``"foo"`` but it can be used to store more
+    complex values such as lists too.  Only constants with a safe
+    representation (objects where ``eval(repr(x)) == x`` is true).
+    """
+    fields = ('value',)
+
+    def as_const(self, eval_ctx=None):
+        rv = self.value
+        if PY2 and type(rv) is text_type and \
+           self.environment.policies['compiler.ascii_str']:
+            try:
+                rv = rv.encode('ascii')
+            except UnicodeError:
+                pass
+        return rv
+
+    @classmethod
+    def from_untrusted(cls, value, lineno=None, environment=None):
+        """Return a const object if the value is representable as
+        constant value in the generated code, otherwise it will raise
+        an `Impossible` exception.
+        """
+        from .compiler import has_safe_repr
+        if not has_safe_repr(value):
+            raise Impossible()
+        return cls(value, lineno=lineno, environment=environment)
+
+
+class TemplateData(Literal):
+    """A constant template string."""
+    fields = ('data',)
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        if eval_ctx.volatile:
+            raise Impossible()
+        if eval_ctx.autoescape:
+            return Markup(self.data)
+        return self.data
+
+
+class Tuple(Literal):
+    """For loop unpacking and some other things like multiple arguments
+    for subscripts.  Like for :class:`Name` `ctx` specifies if the tuple
+    is used for loading the names or storing.
+    """
+    fields = ('items', 'ctx')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return tuple(x.as_const(eval_ctx) for x in self.items)
+
+    def can_assign(self):
+        for item in self.items:
+            if not item.can_assign():
+                return False
+        return True
+
+
+class List(Literal):
+    """Any list literal such as ``[1, 2, 3]``"""
+    fields = ('items',)
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return [x.as_const(eval_ctx) for x in self.items]
+
+
+class Dict(Literal):
+    """Any dict literal such as ``{1: 2, 3: 4}``.  The items must be a list of
+    :class:`Pair` nodes.
+    """
+    fields = ('items',)
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return dict(x.as_const(eval_ctx) for x in self.items)
+
+
+class Pair(Helper):
+    """A key, value pair for dicts."""
+    fields = ('key', 'value')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return self.key.as_const(eval_ctx), self.value.as_const(eval_ctx)
+
+
+class Keyword(Helper):
+    """A key, value pair for keyword arguments where key is a string."""
+    fields = ('key', 'value')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return self.key, self.value.as_const(eval_ctx)
+
+
+class CondExpr(Expr):
+    """A conditional expression (inline if expression).  (``{{
+    foo if bar else baz }}``)
+    """
+    fields = ('test', 'expr1', 'expr2')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        if self.test.as_const(eval_ctx):
+            return self.expr1.as_const(eval_ctx)
+
+        # if we evaluate to an undefined object, we better do that at runtime
+        if self.expr2 is None:
+            raise Impossible()
+
+        return self.expr2.as_const(eval_ctx)
+
+
+def args_as_const(node, eval_ctx):
+    args = [x.as_const(eval_ctx) for x in node.args]
+    kwargs = dict(x.as_const(eval_ctx) for x in node.kwargs)
+
+    if node.dyn_args is not None:
+        try:
+            args.extend(node.dyn_args.as_const(eval_ctx))
+        except Exception:
+            raise Impossible()
+
+    if node.dyn_kwargs is not None:
+        try:
+            kwargs.update(node.dyn_kwargs.as_const(eval_ctx))
+        except Exception:
+            raise Impossible()
+
+    return args, kwargs
+
+
+class Filter(Expr):
+    """This node applies a filter on an expression.  `name` is the name of
+    the filter, the rest of the fields are the same as for :class:`Call`.
+
+    If the `node` of a filter is `None` the contents of the last buffer are
+    filtered.  Buffers are created by macros and filter blocks.
+    """
+
+    fields = ('node', 'name', 'args', 'kwargs', 'dyn_args', 'dyn_kwargs')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+
+        if eval_ctx.volatile or self.node is None:
+            raise Impossible()
+
+        # we have to be careful here because we call filter_ below.
+        # if this variable would be called filter, 2to3 would wrap the
+        # call in a list beause it is assuming we are talking about the
+        # builtin filter function here which no longer returns a list in
+        # python 3.  because of that, do not rename filter_ to filter!
+        filter_ = self.environment.filters.get(self.name)
+
+        if filter_ is None or getattr(filter_, 'contextfilter', False):
+            raise Impossible()
+
+        # We cannot constant handle async filters, so we need to make sure
+        # to not go down this path.
+        if (
+            eval_ctx.environment.is_async
+            and getattr(filter_, 'asyncfiltervariant', False)
+        ):
+            raise Impossible()
+
+        args, kwargs = args_as_const(self, eval_ctx)
+        args.insert(0, self.node.as_const(eval_ctx))
+
+        if getattr(filter_, 'evalcontextfilter', False):
+            args.insert(0, eval_ctx)
+        elif getattr(filter_, 'environmentfilter', False):
+            args.insert(0, self.environment)
+
+        try:
+            return filter_(*args, **kwargs)
+        except Exception:
+            raise Impossible()
+
+
+class Test(Expr):
+    """Applies a test on an expression.  `name` is the name of the test, the
+    rest of the fields are the same as for :class:`Call`.
+    """
+
+    fields = ('node', 'name', 'args', 'kwargs', 'dyn_args', 'dyn_kwargs')
+
+    def as_const(self, eval_ctx=None):
+        test = self.environment.tests.get(self.name)
+
+        if test is None:
+            raise Impossible()
+
+        eval_ctx = get_eval_context(self, eval_ctx)
+        args, kwargs = args_as_const(self, eval_ctx)
+        args.insert(0, self.node.as_const(eval_ctx))
+
+        try:
+            return test(*args, **kwargs)
+        except Exception:
+            raise Impossible()
+
+
+class Call(Expr):
+    """Calls an expression.  `args` is a list of arguments, `kwargs` a list
+    of keyword arguments (list of :class:`Keyword` nodes), and `dyn_args`
+    and `dyn_kwargs` has to be either `None` or a node that is used as
+    node for dynamic positional (``*args``) or keyword (``**kwargs``)
+    arguments.
+    """
+    fields = ('node', 'args', 'kwargs', 'dyn_args', 'dyn_kwargs')
+
+
+class Getitem(Expr):
+    """Get an attribute or item from an expression and prefer the item."""
+    fields = ('node', 'arg', 'ctx')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        if self.ctx != 'load':
+            raise Impossible()
+        try:
+            return self.environment.getitem(self.node.as_const(eval_ctx),
+                                            self.arg.as_const(eval_ctx))
+        except Exception:
+            raise Impossible()
+
+    def can_assign(self):
+        return False
+
+
+class Getattr(Expr):
+    """Get an attribute or item from an expression that is a ascii-only
+    bytestring and prefer the attribute.
+    """
+    fields = ('node', 'attr', 'ctx')
+
+    def as_const(self, eval_ctx=None):
+        if self.ctx != 'load':
+            raise Impossible()
+        try:
+            eval_ctx = get_eval_context(self, eval_ctx)
+            return self.environment.getattr(self.node.as_const(eval_ctx),
+                                            self.attr)
+        except Exception:
+            raise Impossible()
+
+    def can_assign(self):
+        return False
+
+
+class Slice(Expr):
+    """Represents a slice object.  This must only be used as argument for
+    :class:`Subscript`.
+    """
+    fields = ('start', 'stop', 'step')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        def const(obj):
+            if obj is None:
+                return None
+            return obj.as_const(eval_ctx)
+        return slice(const(self.start), const(self.stop), const(self.step))
+
+
+class Concat(Expr):
+    """Concatenates the list of expressions provided after converting them to
+    unicode.
+    """
+    fields = ('nodes',)
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return ''.join(text_type(x.as_const(eval_ctx)) for x in self.nodes)
+
+
+class Compare(Expr):
+    """Compares an expression with some other expressions.  `ops` must be a
+    list of :class:`Operand`\\s.
+    """
+    fields = ('expr', 'ops')
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        result = value = self.expr.as_const(eval_ctx)
+        try:
+            for op in self.ops:
+                new_value = op.expr.as_const(eval_ctx)
+                result = _cmpop_to_func[op.op](value, new_value)
+                value = new_value
+        except Exception:
+            raise Impossible()
+        return result
+
+
+class Operand(Helper):
+    """Holds an operator and an expression."""
+    fields = ('op', 'expr')
+
+if __debug__:
+    Operand.__doc__ += '\nThe following operators are available: ' + \
+        ', '.join(sorted('``%s``' % x for x in set(_binop_to_func) |
+                  set(_uaop_to_func) | set(_cmpop_to_func)))
+
+
+class Mul(BinExpr):
+    """Multiplies the left with the right node."""
+    operator = '*'
+
+
+class Div(BinExpr):
+    """Divides the left by the right node."""
+    operator = '/'
+
+
+class FloorDiv(BinExpr):
+    """Divides the left by the right node and truncates conver the
+    result into an integer by truncating.
+    """
+    operator = '//'
+
+
+class Add(BinExpr):
+    """Add the left to the right node."""
+    operator = '+'
+
+
+class Sub(BinExpr):
+    """Subtract the right from the left node."""
+    operator = '-'
+
+
+class Mod(BinExpr):
+    """Left modulo right."""
+    operator = '%'
+
+
+class Pow(BinExpr):
+    """Left to the power of right."""
+    operator = '**'
+
+
+class And(BinExpr):
+    """Short circuited AND."""
+    operator = 'and'
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return self.left.as_const(eval_ctx) and self.right.as_const(eval_ctx)
+
+
+class Or(BinExpr):
+    """Short circuited OR."""
+    operator = 'or'
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return self.left.as_const(eval_ctx) or self.right.as_const(eval_ctx)
+
+
+class Not(UnaryExpr):
+    """Negate the expression."""
+    operator = 'not'
+
+
+class Neg(UnaryExpr):
+    """Make the expression negative."""
+    operator = '-'
+
+
+class Pos(UnaryExpr):
+    """Make the expression positive (noop for most expressions)"""
+    operator = '+'
+
+
+# Helpers for extensions
+
+
+class EnvironmentAttribute(Expr):
+    """Loads an attribute from the environment object.  This is useful for
+    extensions that want to call a callback stored on the environment.
+    """
+    fields = ('name',)
+
+
+class ExtensionAttribute(Expr):
+    """Returns the attribute of an extension bound to the environment.
+    The identifier is the identifier of the :class:`Extension`.
+
+    This node is usually constructed by calling the
+    :meth:`~jinja2.ext.Extension.attr` method on an extension.
+    """
+    fields = ('identifier', 'name')
+
+
+class ImportedName(Expr):
+    """If created with an import name the import name is returned on node
+    access.  For example ``ImportedName('cgi.escape')`` returns the `escape`
+    function from the cgi module on evaluation.  Imports are optimized by the
+    compiler so there is no need to assign them to local variables.
+    """
+    fields = ('importname',)
+
+
+class InternalName(Expr):
+    """An internal name in the compiler.  You cannot create these nodes
+    yourself but the parser provides a
+    :meth:`~jinja2.parser.Parser.free_identifier` method that creates
+    a new identifier for you.  This identifier is not available from the
+    template and is not threated specially by the compiler.
+    """
+    fields = ('name',)
+
+    def __init__(self):
+        raise TypeError('Can\'t create internal names.  Use the '
+                        '`free_identifier` method on a parser.')
+
+
+class MarkSafe(Expr):
+    """Mark the wrapped expression as safe (wrap it as `Markup`)."""
+    fields = ('expr',)
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        return Markup(self.expr.as_const(eval_ctx))
+
+
+class MarkSafeIfAutoescape(Expr):
+    """Mark the wrapped expression as safe (wrap it as `Markup`) but
+    only if autoescaping is active.
+
+    .. versionadded:: 2.5
+    """
+    fields = ('expr',)
+
+    def as_const(self, eval_ctx=None):
+        eval_ctx = get_eval_context(self, eval_ctx)
+        if eval_ctx.volatile:
+            raise Impossible()
+        expr = self.expr.as_const(eval_ctx)
+        if eval_ctx.autoescape:
+            return Markup(expr)
+        return expr
+
+
+class ContextReference(Expr):
+    """Returns the current template context.  It can be used like a
+    :class:`Name` node, with a ``'load'`` ctx and will return the
+    current :class:`~jinja2.runtime.Context` object.
+
+    Here an example that assigns the current template name to a
+    variable named `foo`::
+
+        Assign(Name('foo', ctx='store'),
+               Getattr(ContextReference(), 'name'))
+    """
+
+
+class Continue(Stmt):
+    """Continue a loop."""
+
+
+class Break(Stmt):
+    """Break a loop."""
+
+
+class Scope(Stmt):
+    """An artificial scope."""
+    fields = ('body',)
+
+
+class OverlayScope(Stmt):
+    """An overlay scope for extensions.  This is a largely unoptimized scope
+    that however can be used to introduce completely arbitrary variables into
+    a sub scope from a dictionary or dictionary like object.  The `context`
+    field has to evaluate to a dictionary object.
+
+    Example usage::
+
+        OverlayScope(context=self.call_method('get_context'),
+                     body=[...])
+
+    .. versionadded:: 2.10
+    """
+    fields = ('context', 'body')
+
+
+class EvalContextModifier(Stmt):
+    """Modifies the eval context.  For each option that should be modified,
+    a :class:`Keyword` has to be added to the :attr:`options` list.
+
+    Example to change the `autoescape` setting::
+
+        EvalContextModifier(options=[Keyword('autoescape', Const(True))])
+    """
+    fields = ('options',)
+
+
+class ScopedEvalContextModifier(EvalContextModifier):
+    """Modifies the eval context and reverts it later.  Works exactly like
+    :class:`EvalContextModifier` but will only modify the
+    :class:`~jinja2.nodes.EvalContext` for nodes in the :attr:`body`.
+    """
+    fields = ('body',)
+
+
+# make sure nobody creates custom nodes
+def _failing_new(*args, **kwargs):
+    raise TypeError('can\'t create custom node types')
+NodeType.__new__ = staticmethod(_failing_new); del _failing_new

cement/cli/contrib/jinja2/optimizer.py

@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.optimizer
+    ~~~~~~~~~~~~~~~~
+
+    The jinja optimizer is currently trying to constant fold a few expressions
+    and modify the AST in place so that it should be easier to evaluate it.
+
+    Because the AST does not contain all the scoping information and the
+    compiler has to find that out, we cannot do all the optimizations we
+    want.  For example loop unrolling doesn't work because unrolled loops would
+    have a different scoping.
+
+    The solution would be a second syntax tree that has the scoping rules stored.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD.
+"""
+from jinja2 import nodes
+from jinja2.visitor import NodeTransformer
+
+
+def optimize(node, environment):
+    """The context hint can be used to perform an static optimization
+    based on the context given."""
+    optimizer = Optimizer(environment)
+    return optimizer.visit(node)
+
+
+class Optimizer(NodeTransformer):
+
+    def __init__(self, environment):
+        self.environment = environment
+
+    def fold(self, node, eval_ctx=None):
+        """Do constant folding."""
+        node = self.generic_visit(node)
+        try:
+            return nodes.Const.from_untrusted(node.as_const(eval_ctx),
+                                              lineno=node.lineno,
+                                              environment=self.environment)
+        except nodes.Impossible:
+            return node
+
+    visit_Add = visit_Sub = visit_Mul = visit_Div = visit_FloorDiv = \
+    visit_Pow = visit_Mod = visit_And = visit_Or = visit_Pos = visit_Neg = \
+    visit_Not = visit_Compare = visit_Getitem = visit_Getattr = visit_Call = \
+    visit_Filter = visit_Test = visit_CondExpr = fold
+    del fold

cement/cli/contrib/jinja2/parser.py

@@ -0,0 +1,903 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.parser
+    ~~~~~~~~~~~~~
+
+    Implements the template parser.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+from jinja2 import nodes
+from jinja2.exceptions import TemplateSyntaxError, TemplateAssertionError
+from jinja2.lexer import describe_token, describe_token_expr
+from jinja2._compat import imap
+
+
+_statement_keywords = frozenset(['for', 'if', 'block', 'extends', 'print',
+                                 'macro', 'include', 'from', 'import',
+                                 'set', 'with', 'autoescape'])
+_compare_operators = frozenset(['eq', 'ne', 'lt', 'lteq', 'gt', 'gteq'])
+
+_math_nodes = {
+    'add': nodes.Add,
+    'sub': nodes.Sub,
+    'mul': nodes.Mul,
+    'div': nodes.Div,
+    'floordiv': nodes.FloorDiv,
+    'mod': nodes.Mod,
+}
+
+
+class Parser(object):
+    """This is the central parsing class Jinja2 uses.  It's passed to
+    extensions and can be used to parse expressions or statements.
+    """
+
+    def __init__(self, environment, source, name=None, filename=None,
+                 state=None):
+        self.environment = environment
+        self.stream = environment._tokenize(source, name, filename, state)
+        self.name = name
+        self.filename = filename
+        self.closed = False
+        self.extensions = {}
+        for extension in environment.iter_extensions():
+            for tag in extension.tags:
+                self.extensions[tag] = extension.parse
+        self._last_identifier = 0
+        self._tag_stack = []
+        self._end_token_stack = []
+
+    def fail(self, msg, lineno=None, exc=TemplateSyntaxError):
+        """Convenience method that raises `exc` with the message, passed
+        line number or last line number as well as the current name and
+        filename.
+        """
+        if lineno is None:
+            lineno = self.stream.current.lineno
+        raise exc(msg, lineno, self.name, self.filename)
+
+    def _fail_ut_eof(self, name, end_token_stack, lineno):
+        expected = []
+        for exprs in end_token_stack:
+            expected.extend(imap(describe_token_expr, exprs))
+        if end_token_stack:
+            currently_looking = ' or '.join(
+                "'%s'" % describe_token_expr(expr)
+                for expr in end_token_stack[-1])
+        else:
+            currently_looking = None
+
+        if name is None:
+            message = ['Unexpected end of template.']
+        else:
+            message = ['Encountered unknown tag \'%s\'.' % name]
+
+        if currently_looking:
+            if name is not None and name in expected:
+                message.append('You probably made a nesting mistake. Jinja '
+                               'is expecting this tag, but currently looking '
+                               'for %s.' % currently_looking)
+            else:
+                message.append('Jinja was looking for the following tags: '
+                               '%s.' % currently_looking)
+
+        if self._tag_stack:
+            message.append('The innermost block that needs to be '
+                           'closed is \'%s\'.' % self._tag_stack[-1])
+
+        self.fail(' '.join(message), lineno)
+
+    def fail_unknown_tag(self, name, lineno=None):
+        """Called if the parser encounters an unknown tag.  Tries to fail
+        with a human readable error message that could help to identify
+        the problem.
+        """
+        return self._fail_ut_eof(name, self._end_token_stack, lineno)
+
+    def fail_eof(self, end_tokens=None, lineno=None):
+        """Like fail_unknown_tag but for end of template situations."""
+        stack = list(self._end_token_stack)
+        if end_tokens is not None:
+            stack.append(end_tokens)
+        return self._fail_ut_eof(None, stack, lineno)
+
+    def is_tuple_end(self, extra_end_rules=None):
+        """Are we at the end of a tuple?"""
+        if self.stream.current.type in ('variable_end', 'block_end', 'rparen'):
+            return True
+        elif extra_end_rules is not None:
+            return self.stream.current.test_any(extra_end_rules)
+        return False
+
+    def free_identifier(self, lineno=None):
+        """Return a new free identifier as :class:`~jinja2.nodes.InternalName`."""
+        self._last_identifier += 1
+        rv = object.__new__(nodes.InternalName)
+        nodes.Node.__init__(rv, 'fi%d' % self._last_identifier, lineno=lineno)
+        return rv
+
+    def parse_statement(self):
+        """Parse a single statement."""
+        token = self.stream.current
+        if token.type != 'name':
+            self.fail('tag name expected', token.lineno)
+        self._tag_stack.append(token.value)
+        pop_tag = True
+        try:
+            if token.value in _statement_keywords:
+                return getattr(self, 'parse_' + self.stream.current.value)()
+            if token.value == 'call':
+                return self.parse_call_block()
+            if token.value == 'filter':
+                return self.parse_filter_block()
+            ext = self.extensions.get(token.value)
+            if ext is not None:
+                return ext(self)
+
+            # did not work out, remove the token we pushed by accident
+            # from the stack so that the unknown tag fail function can
+            # produce a proper error message.
+            self._tag_stack.pop()
+            pop_tag = False
+            self.fail_unknown_tag(token.value, token.lineno)
+        finally:
+            if pop_tag:
+                self._tag_stack.pop()
+
+    def parse_statements(self, end_tokens, drop_needle=False):
+        """Parse multiple statements into a list until one of the end tokens
+        is reached.  This is used to parse the body of statements as it also
+        parses template data if appropriate.  The parser checks first if the
+        current token is a colon and skips it if there is one.  Then it checks
+        for the block end and parses until if one of the `end_tokens` is
+        reached.  Per default the active token in the stream at the end of
+        the call is the matched end token.  If this is not wanted `drop_needle`
+        can be set to `True` and the end token is removed.
+        """
+        # the first token may be a colon for python compatibility
+        self.stream.skip_if('colon')
+
+        # in the future it would be possible to add whole code sections
+        # by adding some sort of end of statement token and parsing those here.
+        self.stream.expect('block_end')
+        result = self.subparse(end_tokens)
+
+        # we reached the end of the template too early, the subparser
+        # does not check for this, so we do that now
+        if self.stream.current.type == 'eof':
+            self.fail_eof(end_tokens)
+
+        if drop_needle:
+            next(self.stream)
+        return result
+
+    def parse_set(self):
+        """Parse an assign statement."""
+        lineno = next(self.stream).lineno
+        target = self.parse_assign_target(with_namespace=True)
+        if self.stream.skip_if('assign'):
+            expr = self.parse_tuple()
+            return nodes.Assign(target, expr, lineno=lineno)
+        filter_node = self.parse_filter(None)
+        body = self.parse_statements(('name:endset',),
+                                     drop_needle=True)
+        return nodes.AssignBlock(target, filter_node, body, lineno=lineno)
+
+    def parse_for(self):
+        """Parse a for loop."""
+        lineno = self.stream.expect('name:for').lineno
+        target = self.parse_assign_target(extra_end_rules=('name:in',))
+        self.stream.expect('name:in')
+        iter = self.parse_tuple(with_condexpr=False,
+                                extra_end_rules=('name:recursive',))
+        test = None
+        if self.stream.skip_if('name:if'):
+            test = self.parse_expression()
+        recursive = self.stream.skip_if('name:recursive')
+        body = self.parse_statements(('name:endfor', 'name:else'))
+        if next(self.stream).value == 'endfor':
+            else_ = []
+        else:
+            else_ = self.parse_statements(('name:endfor',), drop_needle=True)
+        return nodes.For(target, iter, body, else_, test,
+                         recursive, lineno=lineno)
+
+    def parse_if(self):
+        """Parse an if construct."""
+        node = result = nodes.If(lineno=self.stream.expect('name:if').lineno)
+        while 1:
+            node.test = self.parse_tuple(with_condexpr=False)
+            node.body = self.parse_statements(('name:elif', 'name:else',
+                                               'name:endif'))
+            node.elif_ = []
+            node.else_ = []
+            token = next(self.stream)
+            if token.test('name:elif'):
+                node = nodes.If(lineno=self.stream.current.lineno)
+                result.elif_.append(node)
+                continue
+            elif token.test('name:else'):
+                result.else_ = self.parse_statements(('name:endif',),
+                                                     drop_needle=True)
+            break
+        return result
+
+    def parse_with(self):
+        node = nodes.With(lineno=next(self.stream).lineno)
+        targets = []
+        values = []
+        while self.stream.current.type != 'block_end':
+            lineno = self.stream.current.lineno
+            if targets:
+                self.stream.expect('comma')
+            target = self.parse_assign_target()
+            target.set_ctx('param')
+            targets.append(target)
+            self.stream.expect('assign')
+            values.append(self.parse_expression())
+        node.targets = targets
+        node.values = values
+        node.body = self.parse_statements(('name:endwith',),
+                                          drop_needle=True)
+        return node
+
+    def parse_autoescape(self):
+        node = nodes.ScopedEvalContextModifier(lineno=next(self.stream).lineno)
+        node.options = [
+            nodes.Keyword('autoescape', self.parse_expression())
+        ]
+        node.body = self.parse_statements(('name:endautoescape',),
+                                            drop_needle=True)
+        return nodes.Scope([node])
+
+    def parse_block(self):
+        node = nodes.Block(lineno=next(self.stream).lineno)
+        node.name = self.stream.expect('name').value
+        node.scoped = self.stream.skip_if('name:scoped')
+
+        # common problem people encounter when switching from django
+        # to jinja.  we do not support hyphens in block names, so let's
+        # raise a nicer error message in that case.
+        if self.stream.current.type == 'sub':
+            self.fail('Block names in Jinja have to be valid Python '
+                      'identifiers and may not contain hyphens, use an '
+                      'underscore instead.')
+
+        node.body = self.parse_statements(('name:endblock',), drop_needle=True)
+        self.stream.skip_if('name:' + node.name)
+        return node
+
+    def parse_extends(self):
+        node = nodes.Extends(lineno=next(self.stream).lineno)
+        node.template = self.parse_expression()
+        return node
+
+    def parse_import_context(self, node, default):
+        if self.stream.current.test_any('name:with', 'name:without') and \
+           self.stream.look().test('name:context'):
+            node.with_context = next(self.stream).value == 'with'
+            self.stream.skip()
+        else:
+            node.with_context = default
+        return node
+
+    def parse_include(self):
+        node = nodes.Include(lineno=next(self.stream).lineno)
+        node.template = self.parse_expression()
+        if self.stream.current.test('name:ignore') and \
+           self.stream.look().test('name:missing'):
+            node.ignore_missing = True
+            self.stream.skip(2)
+        else:
+            node.ignore_missing = False
+        return self.parse_import_context(node, True)
+
+    def parse_import(self):
+        node = nodes.Import(lineno=next(self.stream).lineno)
+        node.template = self.parse_expression()
+        self.stream.expect('name:as')
+        node.target = self.parse_assign_target(name_only=True).name
+        return self.parse_import_context(node, False)
+
+    def parse_from(self):
+        node = nodes.FromImport(lineno=next(self.stream).lineno)
+        node.template = self.parse_expression()
+        self.stream.expect('name:import')
+        node.names = []
+
+        def parse_context():
+            if self.stream.current.value in ('with', 'without') and \
+               self.stream.look().test('name:context'):
+                node.with_context = next(self.stream).value == 'with'
+                self.stream.skip()
+                return True
+            return False
+
+        while 1:
+            if node.names:
+                self.stream.expect('comma')
+            if self.stream.current.type == 'name':
+                if parse_context():
+                    break
+                target = self.parse_assign_target(name_only=True)
+                if target.name.startswith('_'):
+                    self.fail('names starting with an underline can not '
+                              'be imported', target.lineno,
+                              exc=TemplateAssertionError)
+                if self.stream.skip_if('name:as'):
+                    alias = self.parse_assign_target(name_only=True)
+                    node.names.append((target.name, alias.name))
+                else:
+                    node.names.append(target.name)
+                if parse_context() or self.stream.current.type != 'comma':
+                    break
+            else:
+                self.stream.expect('name')
+        if not hasattr(node, 'with_context'):
+            node.with_context = False
+        return node
+
+    def parse_signature(self, node):
+        node.args = args = []
+        node.defaults = defaults = []
+        self.stream.expect('lparen')
+        while self.stream.current.type != 'rparen':
+            if args:
+                self.stream.expect('comma')
+            arg = self.parse_assign_target(name_only=True)
+            arg.set_ctx('param')
+            if self.stream.skip_if('assign'):
+                defaults.append(self.parse_expression())
+            elif defaults:
+                self.fail('non-default argument follows default argument')
+            args.append(arg)
+        self.stream.expect('rparen')
+
+    def parse_call_block(self):
+        node = nodes.CallBlock(lineno=next(self.stream).lineno)
+        if self.stream.current.type == 'lparen':
+            self.parse_signature(node)
+        else:
+            node.args = []
+            node.defaults = []
+
+        node.call = self.parse_expression()
+        if not isinstance(node.call, nodes.Call):
+            self.fail('expected call', node.lineno)
+        node.body = self.parse_statements(('name:endcall',), drop_needle=True)
+        return node
+
+    def parse_filter_block(self):
+        node = nodes.FilterBlock(lineno=next(self.stream).lineno)
+        node.filter = self.parse_filter(None, start_inline=True)
+        node.body = self.parse_statements(('name:endfilter',),
+                                          drop_needle=True)
+        return node
+
+    def parse_macro(self):
+        node = nodes.Macro(lineno=next(self.stream).lineno)
+        node.name = self.parse_assign_target(name_only=True).name
+        self.parse_signature(node)
+        node.body = self.parse_statements(('name:endmacro',),
+                                          drop_needle=True)
+        return node
+
+    def parse_print(self):
+        node = nodes.Output(lineno=next(self.stream).lineno)
+        node.nodes = []
+        while self.stream.current.type != 'block_end':
+            if node.nodes:
+                self.stream.expect('comma')
+            node.nodes.append(self.parse_expression())
+        return node
+
+    def parse_assign_target(self, with_tuple=True, name_only=False,
+                            extra_end_rules=None, with_namespace=False):
+        """Parse an assignment target.  As Jinja2 allows assignments to
+        tuples, this function can parse all allowed assignment targets.  Per
+        default assignments to tuples are parsed, that can be disable however
+        by setting `with_tuple` to `False`.  If only assignments to names are
+        wanted `name_only` can be set to `True`.  The `extra_end_rules`
+        parameter is forwarded to the tuple parsing function.  If
+        `with_namespace` is enabled, a namespace assignment may be parsed.
+        """
+        if with_namespace and self.stream.look().type == 'dot':
+            token = self.stream.expect('name')
+            next(self.stream)  # dot
+            attr = self.stream.expect('name')
+            target = nodes.NSRef(token.value, attr.value, lineno=token.lineno)
+        elif name_only:
+            token = self.stream.expect('name')
+            target = nodes.Name(token.value, 'store', lineno=token.lineno)
+        else:
+            if with_tuple:
+                target = self.parse_tuple(simplified=True,
+                                          extra_end_rules=extra_end_rules)
+            else:
+                target = self.parse_primary()
+            target.set_ctx('store')
+        if not target.can_assign():
+            self.fail('can\'t assign to %r' % target.__class__.
+                      __name__.lower(), target.lineno)
+        return target
+
+    def parse_expression(self, with_condexpr=True):
+        """Parse an expression.  Per default all expressions are parsed, if
+        the optional `with_condexpr` parameter is set to `False` conditional
+        expressions are not parsed.
+        """
+        if with_condexpr:
+            return self.parse_condexpr()
+        return self.parse_or()
+
+    def parse_condexpr(self):
+        lineno = self.stream.current.lineno
+        expr1 = self.parse_or()
+        while self.stream.skip_if('name:if'):
+            expr2 = self.parse_or()
+            if self.stream.skip_if('name:else'):
+                expr3 = self.parse_condexpr()
+            else:
+                expr3 = None
+            expr1 = nodes.CondExpr(expr2, expr1, expr3, lineno=lineno)
+            lineno = self.stream.current.lineno
+        return expr1
+
+    def parse_or(self):
+        lineno = self.stream.current.lineno
+        left = self.parse_and()
+        while self.stream.skip_if('name:or'):
+            right = self.parse_and()
+            left = nodes.Or(left, right, lineno=lineno)
+            lineno = self.stream.current.lineno
+        return left
+
+    def parse_and(self):
+        lineno = self.stream.current.lineno
+        left = self.parse_not()
+        while self.stream.skip_if('name:and'):
+            right = self.parse_not()
+            left = nodes.And(left, right, lineno=lineno)
+            lineno = self.stream.current.lineno
+        return left
+
+    def parse_not(self):
+        if self.stream.current.test('name:not'):
+            lineno = next(self.stream).lineno
+            return nodes.Not(self.parse_not(), lineno=lineno)
+        return self.parse_compare()
+
+    def parse_compare(self):
+        lineno = self.stream.current.lineno
+        expr = self.parse_math1()
+        ops = []
+        while 1:
+            token_type = self.stream.current.type
+            if token_type in _compare_operators:
+                next(self.stream)
+                ops.append(nodes.Operand(token_type, self.parse_math1()))
+            elif self.stream.skip_if('name:in'):
+                ops.append(nodes.Operand('in', self.parse_math1()))
+            elif (self.stream.current.test('name:not') and
+                  self.stream.look().test('name:in')):
+                self.stream.skip(2)
+                ops.append(nodes.Operand('notin', self.parse_math1()))
+            else:
+                break
+            lineno = self.stream.current.lineno
+        if not ops:
+            return expr
+        return nodes.Compare(expr, ops, lineno=lineno)
+
+    def parse_math1(self):
+        lineno = self.stream.current.lineno
+        left = self.parse_concat()
+        while self.stream.current.type in ('add', 'sub'):
+            cls = _math_nodes[self.stream.current.type]
+            next(self.stream)
+            right = self.parse_concat()
+            left = cls(left, right, lineno=lineno)
+            lineno = self.stream.current.lineno
+        return left
+
+    def parse_concat(self):
+        lineno = self.stream.current.lineno
+        args = [self.parse_math2()]
+        while self.stream.current.type == 'tilde':
+            next(self.stream)
+            args.append(self.parse_math2())
+        if len(args) == 1:
+            return args[0]
+        return nodes.Concat(args, lineno=lineno)
+
+    def parse_math2(self):
+        lineno = self.stream.current.lineno
+        left = self.parse_pow()
+        while self.stream.current.type in ('mul', 'div', 'floordiv', 'mod'):
+            cls = _math_nodes[self.stream.current.type]
+            next(self.stream)
+            right = self.parse_pow()
+            left = cls(left, right, lineno=lineno)
+            lineno = self.stream.current.lineno
+        return left
+
+    def parse_pow(self):
+        lineno = self.stream.current.lineno
+        left = self.parse_unary()
+        while self.stream.current.type == 'pow':
+            next(self.stream)
+            right = self.parse_unary()
+            left = nodes.Pow(left, right, lineno=lineno)
+            lineno = self.stream.current.lineno
+        return left
+
+    def parse_unary(self, with_filter=True):
+        token_type = self.stream.current.type
+        lineno = self.stream.current.lineno
+        if token_type == 'sub':
+            next(self.stream)
+            node = nodes.Neg(self.parse_unary(False), lineno=lineno)
+        elif token_type == 'add':
+            next(self.stream)
+            node = nodes.Pos(self.parse_unary(False), lineno=lineno)
+        else:
+            node = self.parse_primary()
+        node = self.parse_postfix(node)
+        if with_filter:
+            node = self.parse_filter_expr(node)
+        return node
+
+    def parse_primary(self):
+        token = self.stream.current
+        if token.type == 'name':
+            if token.value in ('true', 'false', 'True', 'False'):
+                node = nodes.Const(token.value in ('true', 'True'),
+                                   lineno=token.lineno)
+            elif token.value in ('none', 'None'):
+                node = nodes.Const(None, lineno=token.lineno)
+            else:
+                node = nodes.Name(token.value, 'load', lineno=token.lineno)
+            next(self.stream)
+        elif token.type == 'string':
+            next(self.stream)
+            buf = [token.value]
+            lineno = token.lineno
+            while self.stream.current.type == 'string':
+                buf.append(self.stream.current.value)
+                next(self.stream)
+            node = nodes.Const(''.join(buf), lineno=lineno)
+        elif token.type in ('integer', 'float'):
+            next(self.stream)
+            node = nodes.Const(token.value, lineno=token.lineno)
+        elif token.type == 'lparen':
+            next(self.stream)
+            node = self.parse_tuple(explicit_parentheses=True)
+            self.stream.expect('rparen')
+        elif token.type == 'lbracket':
+            node = self.parse_list()
+        elif token.type == 'lbrace':
+            node = self.parse_dict()
+        else:
+            self.fail("unexpected '%s'" % describe_token(token), token.lineno)
+        return node
+
+    def parse_tuple(self, simplified=False, with_condexpr=True,
+                    extra_end_rules=None, explicit_parentheses=False):
+        """Works like `parse_expression` but if multiple expressions are
+        delimited by a comma a :class:`~jinja2.nodes.Tuple` node is created.
+        This method could also return a regular expression instead of a tuple
+        if no commas where found.
+
+        The default parsing mode is a full tuple.  If `simplified` is `True`
+        only names and literals are parsed.  The `no_condexpr` parameter is
+        forwarded to :meth:`parse_expression`.
+
+        Because tuples do not require delimiters and may end in a bogus comma
+        an extra hint is needed that marks the end of a tuple.  For example
+        for loops support tuples between `for` and `in`.  In that case the
+        `extra_end_rules` is set to ``['name:in']``.
+
+        `explicit_parentheses` is true if the parsing was triggered by an
+        expression in parentheses.  This is used to figure out if an empty
+        tuple is a valid expression or not.
+        """
+        lineno = self.stream.current.lineno
+        if simplified:
+            parse = self.parse_primary
+        elif with_condexpr:
+            parse = self.parse_expression
+        else:
+            parse = lambda: self.parse_expression(with_condexpr=False)
+        args = []
+        is_tuple = False
+        while 1:
+            if args:
+                self.stream.expect('comma')
+            if self.is_tuple_end(extra_end_rules):
+                break
+            args.append(parse())
+            if self.stream.current.type == 'comma':
+                is_tuple = True
+            else:
+                break
+            lineno = self.stream.current.lineno
+
+        if not is_tuple:
+            if args:
+                return args[0]
+
+            # if we don't have explicit parentheses, an empty tuple is
+            # not a valid expression.  This would mean nothing (literally
+            # nothing) in the spot of an expression would be an empty
+            # tuple.
+            if not explicit_parentheses:
+                self.fail('Expected an expression, got \'%s\'' %
+                          describe_token(self.stream.current))
+
+        return nodes.Tuple(args, 'load', lineno=lineno)
+
+    def parse_list(self):
+        token = self.stream.expect('lbracket')
+        items = []
+        while self.stream.current.type != 'rbracket':
+            if items:
+                self.stream.expect('comma')
+            if self.stream.current.type == 'rbracket':
+                break
+            items.append(self.parse_expression())
+        self.stream.expect('rbracket')
+        return nodes.List(items, lineno=token.lineno)
+
+    def parse_dict(self):
+        token = self.stream.expect('lbrace')
+        items = []
+        while self.stream.current.type != 'rbrace':
+            if items:
+                self.stream.expect('comma')
+            if self.stream.current.type == 'rbrace':
+                break
+            key = self.parse_expression()
+            self.stream.expect('colon')
+            value = self.parse_expression()
+            items.append(nodes.Pair(key, value, lineno=key.lineno))
+        self.stream.expect('rbrace')
+        return nodes.Dict(items, lineno=token.lineno)
+
+    def parse_postfix(self, node):
+        while 1:
+            token_type = self.stream.current.type
+            if token_type == 'dot' or token_type == 'lbracket':
+                node = self.parse_subscript(node)
+            # calls are valid both after postfix expressions (getattr
+            # and getitem) as well as filters and tests
+            elif token_type == 'lparen':
+                node = self.parse_call(node)
+            else:
+                break
+        return node
+
+    def parse_filter_expr(self, node):
+        while 1:
+            token_type = self.stream.current.type
+            if token_type == 'pipe':
+                node = self.parse_filter(node)
+            elif token_type == 'name' and self.stream.current.value == 'is':
+                node = self.parse_test(node)
+            # calls are valid both after postfix expressions (getattr
+            # and getitem) as well as filters and tests
+            elif token_type == 'lparen':
+                node = self.parse_call(node)
+            else:
+                break
+        return node
+
+    def parse_subscript(self, node):
+        token = next(self.stream)
+        if token.type == 'dot':
+            attr_token = self.stream.current
+            next(self.stream)
+            if attr_token.type == 'name':
+                return nodes.Getattr(node, attr_token.value, 'load',
+                                     lineno=token.lineno)
+            elif attr_token.type != 'integer':
+                self.fail('expected name or number', attr_token.lineno)
+            arg = nodes.Const(attr_token.value, lineno=attr_token.lineno)
+            return nodes.Getitem(node, arg, 'load', lineno=token.lineno)
+        if token.type == 'lbracket':
+            args = []
+            while self.stream.current.type != 'rbracket':
+                if args:
+                    self.stream.expect('comma')
+                args.append(self.parse_subscribed())
+            self.stream.expect('rbracket')
+            if len(args) == 1:
+                arg = args[0]
+            else:
+                arg = nodes.Tuple(args, 'load', lineno=token.lineno)
+            return nodes.Getitem(node, arg, 'load', lineno=token.lineno)
+        self.fail('expected subscript expression', self.lineno)
+
+    def parse_subscribed(self):
+        lineno = self.stream.current.lineno
+
+        if self.stream.current.type == 'colon':
+            next(self.stream)
+            args = [None]
+        else:
+            node = self.parse_expression()
+            if self.stream.current.type != 'colon':
+                return node
+            next(self.stream)
+            args = [node]
+
+        if self.stream.current.type == 'colon':
+            args.append(None)
+        elif self.stream.current.type not in ('rbracket', 'comma'):
+            args.append(self.parse_expression())
+        else:
+            args.append(None)
+
+        if self.stream.current.type == 'colon':
+            next(self.stream)
+            if self.stream.current.type not in ('rbracket', 'comma'):
+                args.append(self.parse_expression())
+            else:
+                args.append(None)
+        else:
+            args.append(None)
+
+        return nodes.Slice(lineno=lineno, *args)
+
+    def parse_call(self, node):
+        token = self.stream.expect('lparen')
+        args = []
+        kwargs = []
+        dyn_args = dyn_kwargs = None
+        require_comma = False
+
+        def ensure(expr):
+            if not expr:
+                self.fail('invalid syntax for function call expression',
+                          token.lineno)
+
+        while self.stream.current.type != 'rparen':
+            if require_comma:
+                self.stream.expect('comma')
+                # support for trailing comma
+                if self.stream.current.type == 'rparen':
+                    break
+            if self.stream.current.type == 'mul':
+                ensure(dyn_args is None and dyn_kwargs is None)
+                next(self.stream)
+                dyn_args = self.parse_expression()
+            elif self.stream.current.type == 'pow':
+                ensure(dyn_kwargs is None)
+                next(self.stream)
+                dyn_kwargs = self.parse_expression()
+            else:
+                ensure(dyn_args is None and dyn_kwargs is None)
+                if self.stream.current.type == 'name' and \
+                   self.stream.look().type == 'assign':
+                    key = self.stream.current.value
+                    self.stream.skip(2)
+                    value = self.parse_expression()
+                    kwargs.append(nodes.Keyword(key, value,
+                                                lineno=value.lineno))
+                else:
+                    ensure(not kwargs)
+                    args.append(self.parse_expression())
+
+            require_comma = True
+        self.stream.expect('rparen')
+
+        if node is None:
+            return args, kwargs, dyn_args, dyn_kwargs
+        return nodes.Call(node, args, kwargs, dyn_args, dyn_kwargs,
+                          lineno=token.lineno)
+
+    def parse_filter(self, node, start_inline=False):
+        while self.stream.current.type == 'pipe' or start_inline:
+            if not start_inline:
+                next(self.stream)
+            token = self.stream.expect('name')
+            name = token.value
+            while self.stream.current.type == 'dot':
+                next(self.stream)
+                name += '.' + self.stream.expect('name').value
+            if self.stream.current.type == 'lparen':
+                args, kwargs, dyn_args, dyn_kwargs = self.parse_call(None)
+            else:
+                args = []
+                kwargs = []
+                dyn_args = dyn_kwargs = None
+            node = nodes.Filter(node, name, args, kwargs, dyn_args,
+                                dyn_kwargs, lineno=token.lineno)
+            start_inline = False
+        return node
+
+    def parse_test(self, node):
+        token = next(self.stream)
+        if self.stream.current.test('name:not'):
+            next(self.stream)
+            negated = True
+        else:
+            negated = False
+        name = self.stream.expect('name').value
+        while self.stream.current.type == 'dot':
+            next(self.stream)
+            name += '.' + self.stream.expect('name').value
+        dyn_args = dyn_kwargs = None
+        kwargs = []
+        if self.stream.current.type == 'lparen':
+            args, kwargs, dyn_args, dyn_kwargs = self.parse_call(None)
+        elif (self.stream.current.type in ('name', 'string', 'integer',
+                                           'float', 'lparen', 'lbracket',
+                                           'lbrace') and not
+              self.stream.current.test_any('name:else', 'name:or',
+                                           'name:and')):
+            if self.stream.current.test('name:is'):
+                self.fail('You cannot chain multiple tests with is')
+            args = [self.parse_primary()]
+        else:
+            args = []
+        node = nodes.Test(node, name, args, kwargs, dyn_args,
+                          dyn_kwargs, lineno=token.lineno)
+        if negated:
+            node = nodes.Not(node, lineno=token.lineno)
+        return node
+
+    def subparse(self, end_tokens=None):
+        body = []
+        data_buffer = []
+        add_data = data_buffer.append
+
+        if end_tokens is not None:
+            self._end_token_stack.append(end_tokens)
+
+        def flush_data():
+            if data_buffer:
+                lineno = data_buffer[0].lineno
+                body.append(nodes.Output(data_buffer[:], lineno=lineno))
+                del data_buffer[:]
+
+        try:
+            while self.stream:
+                token = self.stream.current
+                if token.type == 'data':
+                    if token.value:
+                        add_data(nodes.TemplateData(token.value,
+                                                    lineno=token.lineno))
+                    next(self.stream)
+                elif token.type == 'variable_begin':
+                    next(self.stream)
+                    add_data(self.parse_tuple(with_condexpr=True))
+                    self.stream.expect('variable_end')
+                elif token.type == 'block_begin':
+                    flush_data()
+                    next(self.stream)
+                    if end_tokens is not None and \
+                       self.stream.current.test_any(*end_tokens):
+                        return body
+                    rv = self.parse_statement()
+                    if isinstance(rv, list):
+                        body.extend(rv)
+                    else:
+                        body.append(rv)
+                    self.stream.expect('block_end')
+                else:
+                    raise AssertionError('internal parsing error')
+
+            flush_data()
+        finally:
+            if end_tokens is not None:
+                self._end_token_stack.pop()
+
+        return body
+
+    def parse(self):
+        """Parse the whole template into a `Template` node."""
+        result = nodes.Template(self.subparse(), lineno=1)
+        result.set_environment(self.environment)
+        return result

cement/cli/contrib/jinja2/runtime.py

@@ -0,0 +1,813 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.runtime
+    ~~~~~~~~~~~~~~
+
+    Runtime helpers.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD.
+"""
+import sys
+
+from itertools import chain
+from types import MethodType
+
+from jinja2.nodes import EvalContext, _context_function_types
+from jinja2.utils import Markup, soft_unicode, escape, missing, concat, \
+     internalcode, object_type_repr, evalcontextfunction, Namespace
+from jinja2.exceptions import UndefinedError, TemplateRuntimeError, \
+     TemplateNotFound
+from jinja2._compat import imap, text_type, iteritems, \
+     implements_iterator, implements_to_string, string_types, PY2, \
+     with_metaclass
+
+
+# these variables are exported to the template runtime
+__all__ = ['LoopContext', 'TemplateReference', 'Macro', 'Markup',
+           'TemplateRuntimeError', 'missing', 'concat', 'escape',
+           'markup_join', 'unicode_join', 'to_string', 'identity',
+           'TemplateNotFound', 'Namespace']
+
+#: the name of the function that is used to convert something into
+#: a string.  We can just use the text type here.
+to_string = text_type
+
+#: the identity function.  Useful for certain things in the environment
+identity = lambda x: x
+
+_first_iteration = object()
+_last_iteration = object()
+
+
+def markup_join(seq):
+    """Concatenation that escapes if necessary and converts to unicode."""
+    buf = []
+    iterator = imap(soft_unicode, seq)
+    for arg in iterator:
+        buf.append(arg)
+        if hasattr(arg, '__html__'):
+            return Markup(u'').join(chain(buf, iterator))
+    return concat(buf)
+
+
+def unicode_join(seq):
+    """Simple args to unicode conversion and concatenation."""
+    return concat(imap(text_type, seq))
+
+
+def new_context(environment, template_name, blocks, vars=None,
+                shared=None, globals=None, locals=None):
+    """Internal helper to for context creation."""
+    if vars is None:
+        vars = {}
+    if shared:
+        parent = vars
+    else:
+        parent = dict(globals or (), **vars)
+    if locals:
+        # if the parent is shared a copy should be created because
+        # we don't want to modify the dict passed
+        if shared:
+            parent = dict(parent)
+        for key, value in iteritems(locals):
+            if value is not missing:
+                parent[key] = value
+    return environment.context_class(environment, parent, template_name,
+                                     blocks)
+
+
+class TemplateReference(object):
+    """The `self` in templates."""
+
+    def __init__(self, context):
+        self.__context = context
+
+    def __getitem__(self, name):
+        blocks = self.__context.blocks[name]
+        return BlockReference(name, self.__context, blocks, 0)
+
+    def __repr__(self):
+        return '<%s %r>' % (
+            self.__class__.__name__,
+            self.__context.name
+        )
+
+
+def _get_func(x):
+    return getattr(x, '__func__', x)
+
+
+class ContextMeta(type):
+
+    def __new__(cls, name, bases, d):
+        rv = type.__new__(cls, name, bases, d)
+        if bases == ():
+            return rv
+
+        resolve = _get_func(rv.resolve)
+        default_resolve = _get_func(Context.resolve)
+        resolve_or_missing = _get_func(rv.resolve_or_missing)
+        default_resolve_or_missing = _get_func(Context.resolve_or_missing)
+
+        # If we have a changed resolve but no changed default or missing
+        # resolve we invert the call logic.
+        if resolve is not default_resolve and \
+           resolve_or_missing is default_resolve_or_missing:
+            rv._legacy_resolve_mode = True
+        elif resolve is default_resolve and \
+             resolve_or_missing is default_resolve_or_missing:
+            rv._fast_resolve_mode = True
+
+        return rv
+
+
+def resolve_or_missing(context, key, missing=missing):
+    if key in context.vars:
+        return context.vars[key]
+    if key in context.parent:
+        return context.parent[key]
+    return missing
+
+
+class Context(with_metaclass(ContextMeta)):
+    """The template context holds the variables of a template.  It stores the
+    values passed to the template and also the names the template exports.
+    Creating instances is neither supported nor useful as it's created
+    automatically at various stages of the template evaluation and should not
+    be created by hand.
+
+    The context is immutable.  Modifications on :attr:`parent` **must not**
+    happen and modifications on :attr:`vars` are allowed from generated
+    template code only.  Template filters and global functions marked as
+    :func:`contextfunction`\\s get the active context passed as first argument
+    and are allowed to access the context read-only.
+
+    The template context supports read only dict operations (`get`,
+    `keys`, `values`, `items`, `iterkeys`, `itervalues`, `iteritems`,
+    `__getitem__`, `__contains__`).  Additionally there is a :meth:`resolve`
+    method that doesn't fail with a `KeyError` but returns an
+    :class:`Undefined` object for missing variables.
+    """
+    # XXX: we want to eventually make this be a deprecation warning and
+    # remove it.
+    _legacy_resolve_mode = False
+    _fast_resolve_mode = False
+
+    def __init__(self, environment, parent, name, blocks):
+        self.parent = parent
+        self.vars = {}
+        self.environment = environment
+        self.eval_ctx = EvalContext(self.environment, name)
+        self.exported_vars = set()
+        self.name = name
+
+        # create the initial mapping of blocks.  Whenever template inheritance
+        # takes place the runtime will update this mapping with the new blocks
+        # from the template.
+        self.blocks = dict((k, [v]) for k, v in iteritems(blocks))
+
+        # In case we detect the fast resolve mode we can set up an alias
+        # here that bypasses the legacy code logic.
+        if self._fast_resolve_mode:
+            self.resolve_or_missing = MethodType(resolve_or_missing, self)
+
+    def super(self, name, current):
+        """Render a parent block."""
+        try:
+            blocks = self.blocks[name]
+            index = blocks.index(current) + 1
+            blocks[index]
+        except LookupError:
+            return self.environment.undefined('there is no parent block '
+                                              'called %r.' % name,
+                                              name='super')
+        return BlockReference(name, self, blocks, index)
+
+    def get(self, key, default=None):
+        """Returns an item from the template context, if it doesn't exist
+        `default` is returned.
+        """
+        try:
+            return self[key]
+        except KeyError:
+            return default
+
+    def resolve(self, key):
+        """Looks up a variable like `__getitem__` or `get` but returns an
+        :class:`Undefined` object with the name of the name looked up.
+        """
+        if self._legacy_resolve_mode:
+            rv = resolve_or_missing(self, key)
+        else:
+            rv = self.resolve_or_missing(key)
+        if rv is missing:
+            return self.environment.undefined(name=key)
+        return rv
+
+    def resolve_or_missing(self, key):
+        """Resolves a variable like :meth:`resolve` but returns the
+        special `missing` value if it cannot be found.
+        """
+        if self._legacy_resolve_mode:
+            rv = self.resolve(key)
+            if isinstance(rv, Undefined):
+                rv = missing
+            return rv
+        return resolve_or_missing(self, key)
+
+    def get_exported(self):
+        """Get a new dict with the exported variables."""
+        return dict((k, self.vars[k]) for k in self.exported_vars)
+
+    def get_all(self):
+        """Return the complete context as dict including the exported
+        variables.  For optimizations reasons this might not return an
+        actual copy so be careful with using it.
+        """
+        if not self.vars:
+            return self.parent
+        if not self.parent:
+            return self.vars
+        return dict(self.parent, **self.vars)
+
+    @internalcode
+    def call(__self, __obj, *args, **kwargs):
+        """Call the callable with the arguments and keyword arguments
+        provided but inject the active context or environment as first
+        argument if the callable is a :func:`contextfunction` or
+        :func:`environmentfunction`.
+        """
+        if __debug__:
+            __traceback_hide__ = True  # noqa
+
+        # Allow callable classes to take a context
+        if hasattr(__obj, '__call__'):
+            fn = __obj.__call__
+            for fn_type in ('contextfunction',
+                            'evalcontextfunction',
+                            'environmentfunction'):
+                if hasattr(fn, fn_type):
+                    __obj = fn
+                    break
+
+        if isinstance(__obj, _context_function_types):
+            if getattr(__obj, 'contextfunction', 0):
+                args = (__self,) + args
+            elif getattr(__obj, 'evalcontextfunction', 0):
+                args = (__self.eval_ctx,) + args
+            elif getattr(__obj, 'environmentfunction', 0):
+                args = (__self.environment,) + args
+        try:
+            return __obj(*args, **kwargs)
+        except StopIteration:
+            return __self.environment.undefined('value was undefined because '
+                                                'a callable raised a '
+                                                'StopIteration exception')
+
+    def derived(self, locals=None):
+        """Internal helper function to create a derived context.  This is
+        used in situations where the system needs a new context in the same
+        template that is independent.
+        """
+        context = new_context(self.environment, self.name, {},
+                              self.get_all(), True, None, locals)
+        context.eval_ctx = self.eval_ctx
+        context.blocks.update((k, list(v)) for k, v in iteritems(self.blocks))
+        return context
+
+    def _all(meth):
+        proxy = lambda self: getattr(self.get_all(), meth)()
+        proxy.__doc__ = getattr(dict, meth).__doc__
+        proxy.__name__ = meth
+        return proxy
+
+    keys = _all('keys')
+    values = _all('values')
+    items = _all('items')
+
+    # not available on python 3
+    if PY2:
+        iterkeys = _all('iterkeys')
+        itervalues = _all('itervalues')
+        iteritems = _all('iteritems')
+    del _all
+
+    def __contains__(self, name):
+        return name in self.vars or name in self.parent
+
+    def __getitem__(self, key):
+        """Lookup a variable or raise `KeyError` if the variable is
+        undefined.
+        """
+        item = self.resolve_or_missing(key)
+        if item is missing:
+            raise KeyError(key)
+        return item
+
+    def __repr__(self):
+        return '<%s %s of %r>' % (
+            self.__class__.__name__,
+            repr(self.get_all()),
+            self.name
+        )
+
+
+# register the context as mapping if possible
+try:
+    from collections import Mapping
+    Mapping.register(Context)
+except ImportError:
+    pass
+
+
+class BlockReference(object):
+    """One block on a template reference."""
+
+    def __init__(self, name, context, stack, depth):
+        self.name = name
+        self._context = context
+        self._stack = stack
+        self._depth = depth
+
+    @property
+    def super(self):
+        """Super the block."""
+        if self._depth + 1 >= len(self._stack):
+            return self._context.environment. \
+                undefined('there is no parent block called %r.' %
+                          self.name, name='super')
+        return BlockReference(self.name, self._context, self._stack,
+                              self._depth + 1)
+
+    @internalcode
+    def __call__(self):
+        rv = concat(self._stack[self._depth](self._context))
+        if self._context.eval_ctx.autoescape:
+            rv = Markup(rv)
+        return rv
+
+
+class LoopContextBase(object):
+    """A loop context for dynamic iteration."""
+
+    _before = _first_iteration
+    _current = _first_iteration
+    _after = _last_iteration
+    _length = None
+
+    def __init__(self, undefined, recurse=None, depth0=0):
+        self._undefined = undefined
+        self._recurse = recurse
+        self.index0 = -1
+        self.depth0 = depth0
+        self._last_checked_value = missing
+
+    def cycle(self, *args):
+        """Cycles among the arguments with the current loop index."""
+        if not args:
+            raise TypeError('no items for cycling given')
+        return args[self.index0 % len(args)]
+
+    def changed(self, *value):
+        """Checks whether the value has changed since the last call."""
+        if self._last_checked_value != value:
+            self._last_checked_value = value
+            return True
+        return False
+
+    first = property(lambda x: x.index0 == 0)
+    last = property(lambda x: x._after is _last_iteration)
+    index = property(lambda x: x.index0 + 1)
+    revindex = property(lambda x: x.length - x.index0)
+    revindex0 = property(lambda x: x.length - x.index)
+    depth = property(lambda x: x.depth0 + 1)
+
+    @property
+    def previtem(self):
+        if self._before is _first_iteration:
+            return self._undefined('there is no previous item')
+        return self._before
+
+    @property
+    def nextitem(self):
+        if self._after is _last_iteration:
+            return self._undefined('there is no next item')
+        return self._after
+
+    def __len__(self):
+        return self.length
+
+    @internalcode
+    def loop(self, iterable):
+        if self._recurse is None:
+            raise TypeError('Tried to call non recursive loop.  Maybe you '
+                            "forgot the 'recursive' modifier.")
+        return self._recurse(iterable, self._recurse, self.depth0 + 1)
+
+    # a nifty trick to enhance the error message if someone tried to call
+    # the the loop without or with too many arguments.
+    __call__ = loop
+    del loop
+
+    def __repr__(self):
+        return '<%s %r/%r>' % (
+            self.__class__.__name__,
+            self.index,
+            self.length
+        )
+
+
+class LoopContext(LoopContextBase):
+
+    def __init__(self, iterable, undefined, recurse=None, depth0=0):
+        LoopContextBase.__init__(self, undefined, recurse, depth0)
+        self._iterator = iter(iterable)
+
+        # try to get the length of the iterable early.  This must be done
+        # here because there are some broken iterators around where there
+        # __len__ is the number of iterations left (i'm looking at your
+        # listreverseiterator!).
+        try:
+            self._length = len(iterable)
+        except (TypeError, AttributeError):
+            self._length = None
+        self._after = self._safe_next()
+
+    @property
+    def length(self):
+        if self._length is None:
+            # if was not possible to get the length of the iterator when
+            # the loop context was created (ie: iterating over a generator)
+            # we have to convert the iterable into a sequence and use the
+            # length of that + the number of iterations so far.
+            iterable = tuple(self._iterator)
+            self._iterator = iter(iterable)
+            iterations_done = self.index0 + 2
+            self._length = len(iterable) + iterations_done
+        return self._length
+
+    def __iter__(self):
+        return LoopContextIterator(self)
+
+    def _safe_next(self):
+        try:
+            return next(self._iterator)
+        except StopIteration:
+            return _last_iteration
+
+
+@implements_iterator
+class LoopContextIterator(object):
+    """The iterator for a loop context."""
+    __slots__ = ('context',)
+
+    def __init__(self, context):
+        self.context = context
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        ctx = self.context
+        ctx.index0 += 1
+        if ctx._after is _last_iteration:
+            raise StopIteration()
+        ctx._before = ctx._current
+        ctx._current = ctx._after
+        ctx._after = ctx._safe_next()
+        return ctx._current, ctx
+
+
+class Macro(object):
+    """Wraps a macro function."""
+
+    def __init__(self, environment, func, name, arguments,
+                 catch_kwargs, catch_varargs, caller,
+                 default_autoescape=None):
+        self._environment = environment
+        self._func = func
+        self._argument_count = len(arguments)
+        self.name = name
+        self.arguments = arguments
+        self.catch_kwargs = catch_kwargs
+        self.catch_varargs = catch_varargs
+        self.caller = caller
+        self.explicit_caller = 'caller' in arguments
+        if default_autoescape is None:
+            default_autoescape = environment.autoescape
+        self._default_autoescape = default_autoescape
+
+    @internalcode
+    @evalcontextfunction
+    def __call__(self, *args, **kwargs):
+        # This requires a bit of explanation,  In the past we used to
+        # decide largely based on compile-time information if a macro is
+        # safe or unsafe.  While there was a volatile mode it was largely
+        # unused for deciding on escaping.  This turns out to be
+        # problemtic for macros because if a macro is safe or not not so
+        # much depends on the escape mode when it was defined but when it
+        # was used.
+        #
+        # Because however we export macros from the module system and
+        # there are historic callers that do not pass an eval context (and
+        # will continue to not pass one), we need to perform an instance
+        # check here.
+        #
+        # This is considered safe because an eval context is not a valid
+        # argument to callables otherwise anwyays.  Worst case here is
+        # that if no eval context is passed we fall back to the compile
+        # time autoescape flag.
+        if args and isinstance(args[0], EvalContext):
+            autoescape = args[0].autoescape
+            args = args[1:]
+        else:
+            autoescape = self._default_autoescape
+
+        # try to consume the positional arguments
+        arguments = list(args[:self._argument_count])
+        off = len(arguments)
+
+        # For information why this is necessary refer to the handling
+        # of caller in the `macro_body` handler in the compiler.
+        found_caller = False
+
+        # if the number of arguments consumed is not the number of
+        # arguments expected we start filling in keyword arguments
+        # and defaults.
+        if off != self._argument_count:
+            for idx, name in enumerate(self.arguments[len(arguments):]):
+                try:
+                    value = kwargs.pop(name)
+                except KeyError:
+                    value = missing
+                if name == 'caller':
+                    found_caller = True
+                arguments.append(value)
+        else:
+            found_caller = self.explicit_caller
+
+        # it's important that the order of these arguments does not change
+        # if not also changed in the compiler's `function_scoping` method.
+        # the order is caller, keyword arguments, positional arguments!
+        if self.caller and not found_caller:
+            caller = kwargs.pop('caller', None)
+            if caller is None:
+                caller = self._environment.undefined('No caller defined',
+                                                     name='caller')
+            arguments.append(caller)
+
+        if self.catch_kwargs:
+            arguments.append(kwargs)
+        elif kwargs:
+            if 'caller' in kwargs:
+                raise TypeError('macro %r was invoked with two values for '
+                                'the special caller argument.  This is '
+                                'most likely a bug.' % self.name)
+            raise TypeError('macro %r takes no keyword argument %r' %
+                            (self.name, next(iter(kwargs))))
+        if self.catch_varargs:
+            arguments.append(args[self._argument_count:])
+        elif len(args) > self._argument_count:
+            raise TypeError('macro %r takes not more than %d argument(s)' %
+                            (self.name, len(self.arguments)))
+
+        return self._invoke(arguments, autoescape)
+
+    def _invoke(self, arguments, autoescape):
+        """This method is being swapped out by the async implementation."""
+        rv = self._func(*arguments)
+        if autoescape:
+            rv = Markup(rv)
+        return rv
+
+    def __repr__(self):
+        return '<%s %s>' % (
+            self.__class__.__name__,
+            self.name is None and 'anonymous' or repr(self.name)
+        )
+
+
+@implements_to_string
+class Undefined(object):
+    """The default undefined type.  This undefined type can be printed and
+    iterated over, but every other access will raise an :exc:`jinja2.exceptions.UndefinedError`:
+
+    >>> foo = Undefined(name='foo')
+    >>> str(foo)
+    ''
+    >>> not foo
+    True
+    >>> foo + 42
+    Traceback (most recent call last):
+      ...
+    jinja2.exceptions.UndefinedError: 'foo' is undefined
+    """
+    __slots__ = ('_undefined_hint', '_undefined_obj', '_undefined_name',
+                 '_undefined_exception')
+
+    def __init__(self, hint=None, obj=missing, name=None, exc=UndefinedError):
+        self._undefined_hint = hint
+        self._undefined_obj = obj
+        self._undefined_name = name
+        self._undefined_exception = exc
+
+    @internalcode
+    def _fail_with_undefined_error(self, *args, **kwargs):
+        """Regular callback function for undefined objects that raises an
+        `jinja2.exceptions.UndefinedError` on call.
+        """
+        if self._undefined_hint is None:
+            if self._undefined_obj is missing:
+                hint = '%r is undefined' % self._undefined_name
+            elif not isinstance(self._undefined_name, string_types):
+                hint = '%s has no element %r' % (
+                    object_type_repr(self._undefined_obj),
+                    self._undefined_name
+                )
+            else:
+                hint = '%r has no attribute %r' % (
+                    object_type_repr(self._undefined_obj),
+                    self._undefined_name
+                )
+        else:
+            hint = self._undefined_hint
+        raise self._undefined_exception(hint)
+
+    @internalcode
+    def __getattr__(self, name):
+        if name[:2] == '__':
+            raise AttributeError(name)
+        return self._fail_with_undefined_error()
+
+    __add__ = __radd__ = __mul__ = __rmul__ = __div__ = __rdiv__ = \
+        __truediv__ = __rtruediv__ = __floordiv__ = __rfloordiv__ = \
+        __mod__ = __rmod__ = __pos__ = __neg__ = __call__ = \
+        __getitem__ = __lt__ = __le__ = __gt__ = __ge__ = __int__ = \
+        __float__ = __complex__ = __pow__ = __rpow__ = __sub__ = \
+        __rsub__ = _fail_with_undefined_error
+
+    def __eq__(self, other):
+        return type(self) is type(other)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __hash__(self):
+        return id(type(self))
+
+    def __str__(self):
+        return u''
+
+    def __len__(self):
+        return 0
+
+    def __iter__(self):
+        if 0:
+            yield None
+
+    def __nonzero__(self):
+        return False
+    __bool__ = __nonzero__
+
+    def __repr__(self):
+        return 'Undefined'
+
+
+def make_logging_undefined(logger=None, base=None):
+    """Given a logger object this returns a new undefined class that will
+    log certain failures.  It will log iterations and printing.  If no
+    logger is given a default logger is created.
+
+    Example::
+
+        logger = logging.getLogger(__name__)
+        LoggingUndefined = make_logging_undefined(
+            logger=logger,
+            base=Undefined
+        )
+
+    .. versionadded:: 2.8
+
+    :param logger: the logger to use.  If not provided, a default logger
+                   is created.
+    :param base: the base class to add logging functionality to.  This
+                 defaults to :class:`Undefined`.
+    """
+    if logger is None:
+        import logging
+        logger = logging.getLogger(__name__)
+        logger.addHandler(logging.StreamHandler(sys.stderr))
+    if base is None:
+        base = Undefined
+
+    def _log_message(undef):
+        if undef._undefined_hint is None:
+            if undef._undefined_obj is missing:
+                hint = '%s is undefined' % undef._undefined_name
+            elif not isinstance(undef._undefined_name, string_types):
+                hint = '%s has no element %s' % (
+                    object_type_repr(undef._undefined_obj),
+                    undef._undefined_name)
+            else:
+                hint = '%s has no attribute %s' % (
+                    object_type_repr(undef._undefined_obj),
+                    undef._undefined_name)
+        else:
+            hint = undef._undefined_hint
+        logger.warning('Template variable warning: %s', hint)
+
+    class LoggingUndefined(base):
+
+        def _fail_with_undefined_error(self, *args, **kwargs):
+            try:
+                return base._fail_with_undefined_error(self, *args, **kwargs)
+            except self._undefined_exception as e:
+                logger.error('Template variable error: %s', str(e))
+                raise e
+
+        def __str__(self):
+            rv = base.__str__(self)
+            _log_message(self)
+            return rv
+
+        def __iter__(self):
+            rv = base.__iter__(self)
+            _log_message(self)
+            return rv
+
+        if PY2:
+            def __nonzero__(self):
+                rv = base.__nonzero__(self)
+                _log_message(self)
+                return rv
+
+            def __unicode__(self):
+                rv = base.__unicode__(self)
+                _log_message(self)
+                return rv
+        else:
+            def __bool__(self):
+                rv = base.__bool__(self)
+                _log_message(self)
+                return rv
+
+    return LoggingUndefined
+
+
+@implements_to_string
+class DebugUndefined(Undefined):
+    """An undefined that returns the debug info when printed.
+
+    >>> foo = DebugUndefined(name='foo')
+    >>> str(foo)
+    '{{ foo }}'
+    >>> not foo
+    True
+    >>> foo + 42
+    Traceback (most recent call last):
+      ...
+    jinja2.exceptions.UndefinedError: 'foo' is undefined
+    """
+    __slots__ = ()
+
+    def __str__(self):
+        if self._undefined_hint is None:
+            if self._undefined_obj is missing:
+                return u'{{ %s }}' % self._undefined_name
+            return '{{ no such element: %s[%r] }}' % (
+                object_type_repr(self._undefined_obj),
+                self._undefined_name
+            )
+        return u'{{ undefined value printed: %s }}' % self._undefined_hint
+
+
+@implements_to_string
+class StrictUndefined(Undefined):
+    """An undefined that barks on print and iteration as well as boolean
+    tests and all kinds of comparisons.  In other words: you can do nothing
+    with it except checking if it's defined using the `defined` test.
+
+    >>> foo = StrictUndefined(name='foo')
+    >>> str(foo)
+    Traceback (most recent call last):
+      ...
+    jinja2.exceptions.UndefinedError: 'foo' is undefined
+    >>> not foo
+    Traceback (most recent call last):
+      ...
+    jinja2.exceptions.UndefinedError: 'foo' is undefined
+    >>> foo + 42
+    Traceback (most recent call last):
+      ...
+    jinja2.exceptions.UndefinedError: 'foo' is undefined
+    """
+    __slots__ = ()
+    __iter__ = __str__ = __len__ = __nonzero__ = __eq__ = \
+        __ne__ = __bool__ = __hash__ = \
+        Undefined._fail_with_undefined_error
+
+
+# remove remaining slots attributes, after the metaclass did the magic they
+# are unneeded and irritating as they contain wrong data for the subclasses.
+del Undefined.__slots__, DebugUndefined.__slots__, StrictUndefined.__slots__

cement/cli/contrib/jinja2/sandbox.py

@@ -0,0 +1,475 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.sandbox
+    ~~~~~~~~~~~~~~
+
+    Adds a sandbox layer to Jinja as it was the default behavior in the old
+    Jinja 1 releases.  This sandbox is slightly different from Jinja 1 as the
+    default behavior is easier to use.
+
+    The behavior can be changed by subclassing the environment.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD.
+"""
+import types
+import operator
+from collections import Mapping
+from jinja2.environment import Environment
+from jinja2.exceptions import SecurityError
+from jinja2._compat import string_types, PY2
+from jinja2.utils import Markup
+
+from markupsafe import EscapeFormatter
+from string import Formatter
+
+
+#: maximum number of items a range may produce
+MAX_RANGE = 100000
+
+#: attributes of function objects that are considered unsafe.
+if PY2:
+    UNSAFE_FUNCTION_ATTRIBUTES = set(['func_closure', 'func_code', 'func_dict',
+                                      'func_defaults', 'func_globals'])
+else:
+    # On versions > python 2 the special attributes on functions are gone,
+    # but they remain on methods and generators for whatever reason.
+    UNSAFE_FUNCTION_ATTRIBUTES = set()
+
+
+#: unsafe method attributes.  function attributes are unsafe for methods too
+UNSAFE_METHOD_ATTRIBUTES = set(['im_class', 'im_func', 'im_self'])
+
+#: unsafe generator attirbutes.
+UNSAFE_GENERATOR_ATTRIBUTES = set(['gi_frame', 'gi_code'])
+
+#: unsafe attributes on coroutines
+UNSAFE_COROUTINE_ATTRIBUTES = set(['cr_frame', 'cr_code'])
+
+#: unsafe attributes on async generators
+UNSAFE_ASYNC_GENERATOR_ATTRIBUTES = set(['ag_code', 'ag_frame'])
+
+import warnings
+
+# make sure we don't warn in python 2.6 about stuff we don't care about
+warnings.filterwarnings('ignore', 'the sets module', DeprecationWarning,
+                        module='jinja2.sandbox')
+
+from collections import deque
+
+_mutable_set_types = (set,)
+_mutable_mapping_types = (dict,)
+_mutable_sequence_types = (list,)
+
+
+# on python 2.x we can register the user collection types
+try:
+    from UserDict import UserDict, DictMixin
+    from UserList import UserList
+    _mutable_mapping_types += (UserDict, DictMixin)
+    _mutable_set_types += (UserList,)
+except ImportError:
+    pass
+
+# if sets is still available, register the mutable set from there as well
+try:
+    from sets import Set
+    _mutable_set_types += (Set,)
+except ImportError:
+    pass
+
+#: register Python 2.6 abstract base classes
+from collections import MutableSet, MutableMapping, MutableSequence
+_mutable_set_types += (MutableSet,)
+_mutable_mapping_types += (MutableMapping,)
+_mutable_sequence_types += (MutableSequence,)
+
+
+_mutable_spec = (
+    (_mutable_set_types, frozenset([
+        'add', 'clear', 'difference_update', 'discard', 'pop', 'remove',
+        'symmetric_difference_update', 'update'
+    ])),
+    (_mutable_mapping_types, frozenset([
+        'clear', 'pop', 'popitem', 'setdefault', 'update'
+    ])),
+    (_mutable_sequence_types, frozenset([
+        'append', 'reverse', 'insert', 'sort', 'extend', 'remove'
+    ])),
+    (deque, frozenset([
+        'append', 'appendleft', 'clear', 'extend', 'extendleft', 'pop',
+        'popleft', 'remove', 'rotate'
+    ]))
+)
+
+
+class _MagicFormatMapping(Mapping):
+    """This class implements a dummy wrapper to fix a bug in the Python
+    standard library for string formatting.
+
+    See https://bugs.python.org/issue13598 for information about why
+    this is necessary.
+    """
+
+    def __init__(self, args, kwargs):
+        self._args = args
+        self._kwargs = kwargs
+        self._last_index = 0
+
+    def __getitem__(self, key):
+        if key == '':
+            idx = self._last_index
+            self._last_index += 1
+            try:
+                return self._args[idx]
+            except LookupError:
+                pass
+            key = str(idx)
+        return self._kwargs[key]
+
+    def __iter__(self):
+        return iter(self._kwargs)
+
+    def __len__(self):
+        return len(self._kwargs)
+
+
+def inspect_format_method(callable):
+    if not isinstance(callable, (types.MethodType,
+                                 types.BuiltinMethodType)) or \
+       callable.__name__ != 'format':
+        return None
+    obj = callable.__self__
+    if isinstance(obj, string_types):
+        return obj
+
+
+def safe_range(*args):
+    """A range that can't generate ranges with a length of more than
+    MAX_RANGE items.
+    """
+    rng = range(*args)
+    if len(rng) > MAX_RANGE:
+        raise OverflowError('range too big, maximum size for range is %d' %
+                            MAX_RANGE)
+    return rng
+
+
+def unsafe(f):
+    """Marks a function or method as unsafe.
+
+    ::
+
+        @unsafe
+        def delete(self):
+            pass
+    """
+    f.unsafe_callable = True
+    return f
+
+
+def is_internal_attribute(obj, attr):
+    """Test if the attribute given is an internal python attribute.  For
+    example this function returns `True` for the `func_code` attribute of
+    python objects.  This is useful if the environment method
+    :meth:`~SandboxedEnvironment.is_safe_attribute` is overridden.
+
+    >>> from jinja2.sandbox import is_internal_attribute
+    >>> is_internal_attribute(str, "mro")
+    True
+    >>> is_internal_attribute(str, "upper")
+    False
+    """
+    if isinstance(obj, types.FunctionType):
+        if attr in UNSAFE_FUNCTION_ATTRIBUTES:
+            return True
+    elif isinstance(obj, types.MethodType):
+        if attr in UNSAFE_FUNCTION_ATTRIBUTES or \
+           attr in UNSAFE_METHOD_ATTRIBUTES:
+            return True
+    elif isinstance(obj, type):
+        if attr == 'mro':
+            return True
+    elif isinstance(obj, (types.CodeType, types.TracebackType, types.FrameType)):
+        return True
+    elif isinstance(obj, types.GeneratorType):
+        if attr in UNSAFE_GENERATOR_ATTRIBUTES:
+            return True
+    elif hasattr(types, 'CoroutineType') and isinstance(obj, types.CoroutineType):
+        if attr in UNSAFE_COROUTINE_ATTRIBUTES:
+            return True
+    elif hasattr(types, 'AsyncGeneratorType') and isinstance(obj, types.AsyncGeneratorType):
+        if attr in UNSAFE_ASYNC_GENERATOR_ATTRIBUTES:
+            return True
+    return attr.startswith('__')
+
+
+def modifies_known_mutable(obj, attr):
+    """This function checks if an attribute on a builtin mutable object
+    (list, dict, set or deque) would modify it if called.  It also supports
+    the "user"-versions of the objects (`sets.Set`, `UserDict.*` etc.) and
+    with Python 2.6 onwards the abstract base classes `MutableSet`,
+    `MutableMapping`, and `MutableSequence`.
+
+    >>> modifies_known_mutable({}, "clear")
+    True
+    >>> modifies_known_mutable({}, "keys")
+    False
+    >>> modifies_known_mutable([], "append")
+    True
+    >>> modifies_known_mutable([], "index")
+    False
+
+    If called with an unsupported object (such as unicode) `False` is
+    returned.
+
+    >>> modifies_known_mutable("foo", "upper")
+    False
+    """
+    for typespec, unsafe in _mutable_spec:
+        if isinstance(obj, typespec):
+            return attr in unsafe
+    return False
+
+
+class SandboxedEnvironment(Environment):
+    """The sandboxed environment.  It works like the regular environment but
+    tells the compiler to generate sandboxed code.  Additionally subclasses of
+    this environment may override the methods that tell the runtime what
+    attributes or functions are safe to access.
+
+    If the template tries to access insecure code a :exc:`SecurityError` is
+    raised.  However also other exceptions may occur during the rendering so
+    the caller has to ensure that all exceptions are caught.
+    """
+    sandboxed = True
+
+    #: default callback table for the binary operators.  A copy of this is
+    #: available on each instance of a sandboxed environment as
+    #: :attr:`binop_table`
+    default_binop_table = {
+        '+':        operator.add,
+        '-':        operator.sub,
+        '*':        operator.mul,
+        '/':        operator.truediv,
+        '//':       operator.floordiv,
+        '**':       operator.pow,
+        '%':        operator.mod
+    }
+
+    #: default callback table for the unary operators.  A copy of this is
+    #: available on each instance of a sandboxed environment as
+    #: :attr:`unop_table`
+    default_unop_table = {
+        '+':        operator.pos,
+        '-':        operator.neg
+    }
+
+    #: a set of binary operators that should be intercepted.  Each operator
+    #: that is added to this set (empty by default) is delegated to the
+    #: :meth:`call_binop` method that will perform the operator.  The default
+    #: operator callback is specified by :attr:`binop_table`.
+    #:
+    #: The following binary operators are interceptable:
+    #: ``//``, ``%``, ``+``, ``*``, ``-``, ``/``, and ``**``
+    #:
+    #: The default operation form the operator table corresponds to the
+    #: builtin function.  Intercepted calls are always slower than the native
+    #: operator call, so make sure only to intercept the ones you are
+    #: interested in.
+    #:
+    #: .. versionadded:: 2.6
+    intercepted_binops = frozenset()
+
+    #: a set of unary operators that should be intercepted.  Each operator
+    #: that is added to this set (empty by default) is delegated to the
+    #: :meth:`call_unop` method that will perform the operator.  The default
+    #: operator callback is specified by :attr:`unop_table`.
+    #:
+    #: The following unary operators are interceptable: ``+``, ``-``
+    #:
+    #: The default operation form the operator table corresponds to the
+    #: builtin function.  Intercepted calls are always slower than the native
+    #: operator call, so make sure only to intercept the ones you are
+    #: interested in.
+    #:
+    #: .. versionadded:: 2.6
+    intercepted_unops = frozenset()
+
+    def intercept_unop(self, operator):
+        """Called during template compilation with the name of a unary
+        operator to check if it should be intercepted at runtime.  If this
+        method returns `True`, :meth:`call_unop` is excuted for this unary
+        operator.  The default implementation of :meth:`call_unop` will use
+        the :attr:`unop_table` dictionary to perform the operator with the
+        same logic as the builtin one.
+
+        The following unary operators are interceptable: ``+`` and ``-``
+
+        Intercepted calls are always slower than the native operator call,
+        so make sure only to intercept the ones you are interested in.
+
+        .. versionadded:: 2.6
+        """
+        return False
+
+
+    def __init__(self, *args, **kwargs):
+        Environment.__init__(self, *args, **kwargs)
+        self.globals['range'] = safe_range
+        self.binop_table = self.default_binop_table.copy()
+        self.unop_table = self.default_unop_table.copy()
+
+    def is_safe_attribute(self, obj, attr, value):
+        """The sandboxed environment will call this method to check if the
+        attribute of an object is safe to access.  Per default all attributes
+        starting with an underscore are considered private as well as the
+        special attributes of internal python objects as returned by the
+        :func:`is_internal_attribute` function.
+        """
+        return not (attr.startswith('_') or is_internal_attribute(obj, attr))
+
+    def is_safe_callable(self, obj):
+        """Check if an object is safely callable.  Per default a function is
+        considered safe unless the `unsafe_callable` attribute exists and is
+        True.  Override this method to alter the behavior, but this won't
+        affect the `unsafe` decorator from this module.
+        """
+        return not (getattr(obj, 'unsafe_callable', False) or
+                    getattr(obj, 'alters_data', False))
+
+    def call_binop(self, context, operator, left, right):
+        """For intercepted binary operator calls (:meth:`intercepted_binops`)
+        this function is executed instead of the builtin operator.  This can
+        be used to fine tune the behavior of certain operators.
+
+        .. versionadded:: 2.6
+        """
+        return self.binop_table[operator](left, right)
+
+    def call_unop(self, context, operator, arg):
+        """For intercepted unary operator calls (:meth:`intercepted_unops`)
+        this function is executed instead of the builtin operator.  This can
+        be used to fine tune the behavior of certain operators.
+
+        .. versionadded:: 2.6
+        """
+        return self.unop_table[operator](arg)
+
+    def getitem(self, obj, argument):
+        """Subscribe an object from sandboxed code."""
+        try:
+            return obj[argument]
+        except (TypeError, LookupError):
+            if isinstance(argument, string_types):
+                try:
+                    attr = str(argument)
+                except Exception:
+                    pass
+                else:
+                    try:
+                        value = getattr(obj, attr)
+                    except AttributeError:
+                        pass
+                    else:
+                        if self.is_safe_attribute(obj, argument, value):
+                            return value
+                        return self.unsafe_undefined(obj, argument)
+        return self.undefined(obj=obj, name=argument)
+
+    def getattr(self, obj, attribute):
+        """Subscribe an object from sandboxed code and prefer the
+        attribute.  The attribute passed *must* be a bytestring.
+        """
+        try:
+            value = getattr(obj, attribute)
+        except AttributeError:
+            try:
+                return obj[attribute]
+            except (TypeError, LookupError):
+                pass
+        else:
+            if self.is_safe_attribute(obj, attribute, value):
+                return value
+            return self.unsafe_undefined(obj, attribute)
+        return self.undefined(obj=obj, name=attribute)
+
+    def unsafe_undefined(self, obj, attribute):
+        """Return an undefined object for unsafe attributes."""
+        return self.undefined('access to attribute %r of %r '
+                              'object is unsafe.' % (
+            attribute,
+            obj.__class__.__name__
+        ), name=attribute, obj=obj, exc=SecurityError)
+
+    def format_string(self, s, args, kwargs):
+        """If a format call is detected, then this is routed through this
+        method so that our safety sandbox can be used for it.
+        """
+        if isinstance(s, Markup):
+            formatter = SandboxedEscapeFormatter(self, s.escape)
+        else:
+            formatter = SandboxedFormatter(self)
+        kwargs = _MagicFormatMapping(args, kwargs)
+        rv = formatter.vformat(s, args, kwargs)
+        return type(s)(rv)
+
+    def call(__self, __context, __obj, *args, **kwargs):
+        """Call an object from sandboxed code."""
+        fmt = inspect_format_method(__obj)
+        if fmt is not None:
+            return __self.format_string(fmt, args, kwargs)
+
+        # the double prefixes are to avoid double keyword argument
+        # errors when proxying the call.
+        if not __self.is_safe_callable(__obj):
+            raise SecurityError('%r is not safely callable' % (__obj,))
+        return __context.call(__obj, *args, **kwargs)
+
+
+class ImmutableSandboxedEnvironment(SandboxedEnvironment):
+    """Works exactly like the regular `SandboxedEnvironment` but does not
+    permit modifications on the builtin mutable objects `list`, `set`, and
+    `dict` by using the :func:`modifies_known_mutable` function.
+    """
+
+    def is_safe_attribute(self, obj, attr, value):
+        if not SandboxedEnvironment.is_safe_attribute(self, obj, attr, value):
+            return False
+        return not modifies_known_mutable(obj, attr)
+
+
+# This really is not a public API apparenlty.
+try:
+    from _string import formatter_field_name_split
+except ImportError:
+    def formatter_field_name_split(field_name):
+        return field_name._formatter_field_name_split()
+
+
+class SandboxedFormatterMixin(object):
+
+    def __init__(self, env):
+        self._env = env
+
+    def get_field(self, field_name, args, kwargs):
+        first, rest = formatter_field_name_split(field_name)
+        obj = self.get_value(first, args, kwargs)
+        for is_attr, i in rest:
+            if is_attr:
+                obj = self._env.getattr(obj, i)
+            else:
+                obj = self._env.getitem(obj, i)
+        return obj, first
+
+class SandboxedFormatter(SandboxedFormatterMixin, Formatter):
+
+    def __init__(self, env):
+        SandboxedFormatterMixin.__init__(self, env)
+        Formatter.__init__(self)
+
+class SandboxedEscapeFormatter(SandboxedFormatterMixin, EscapeFormatter):
+
+    def __init__(self, env, escape):
+        SandboxedFormatterMixin.__init__(self, env)
+        EscapeFormatter.__init__(self, escape)

cement/cli/contrib/jinja2/tests.py

@@ -0,0 +1,175 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.tests
+    ~~~~~~~~~~~~
+
+    Jinja test functions. Used with the "is" operator.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import operator
+import re
+from collections import Mapping
+from jinja2.runtime import Undefined
+from jinja2._compat import text_type, string_types, integer_types
+import decimal
+
+number_re = re.compile(r'^-?\d+(\.\d+)?$')
+regex_type = type(number_re)
+
+
+test_callable = callable
+
+
+def test_odd(value):
+    """Return true if the variable is odd."""
+    return value % 2 == 1
+
+
+def test_even(value):
+    """Return true if the variable is even."""
+    return value % 2 == 0
+
+
+def test_divisibleby(value, num):
+    """Check if a variable is divisible by a number."""
+    return value % num == 0
+
+
+def test_defined(value):
+    """Return true if the variable is defined:
+
+    .. sourcecode:: jinja
+
+        {% if variable is defined %}
+            value of variable: {{ variable }}
+        {% else %}
+            variable is not defined
+        {% endif %}
+
+    See the :func:`default` filter for a simple way to set undefined
+    variables.
+    """
+    return not isinstance(value, Undefined)
+
+
+def test_undefined(value):
+    """Like :func:`defined` but the other way round."""
+    return isinstance(value, Undefined)
+
+
+def test_none(value):
+    """Return true if the variable is none."""
+    return value is None
+
+
+def test_lower(value):
+    """Return true if the variable is lowercased."""
+    return text_type(value).islower()
+
+
+def test_upper(value):
+    """Return true if the variable is uppercased."""
+    return text_type(value).isupper()
+
+
+def test_string(value):
+    """Return true if the object is a string."""
+    return isinstance(value, string_types)
+
+
+def test_mapping(value):
+    """Return true if the object is a mapping (dict etc.).
+
+    .. versionadded:: 2.6
+    """
+    return isinstance(value, Mapping)
+
+
+def test_number(value):
+    """Return true if the variable is a number."""
+    return isinstance(value, integer_types + (float, complex, decimal.Decimal))
+
+
+def test_sequence(value):
+    """Return true if the variable is a sequence. Sequences are variables
+    that are iterable.
+    """
+    try:
+        len(value)
+        value.__getitem__
+    except:
+        return False
+    return True
+
+
+def test_sameas(value, other):
+    """Check if an object points to the same memory address than another
+    object:
+
+    .. sourcecode:: jinja
+
+        {% if foo.attribute is sameas false %}
+            the foo attribute really is the `False` singleton
+        {% endif %}
+    """
+    return value is other
+
+
+def test_iterable(value):
+    """Check if it's possible to iterate over an object."""
+    try:
+        iter(value)
+    except TypeError:
+        return False
+    return True
+
+
+def test_escaped(value):
+    """Check if the value is escaped."""
+    return hasattr(value, '__html__')
+
+
+def test_in(value, seq):
+    """Check if value is in seq.
+
+    .. versionadded:: 2.10
+    """
+    return value in seq
+
+
+TESTS = {
+    'odd':              test_odd,
+    'even':             test_even,
+    'divisibleby':      test_divisibleby,
+    'defined':          test_defined,
+    'undefined':        test_undefined,
+    'none':             test_none,
+    'lower':            test_lower,
+    'upper':            test_upper,
+    'string':           test_string,
+    'mapping':          test_mapping,
+    'number':           test_number,
+    'sequence':         test_sequence,
+    'iterable':         test_iterable,
+    'callable':         test_callable,
+    'sameas':           test_sameas,
+    'escaped':          test_escaped,
+    'in':               test_in,
+    '==':               operator.eq,
+    'eq':               operator.eq,
+    'equalto':          operator.eq,
+    '!=':               operator.ne,
+    'ne':               operator.ne,
+    '>':                operator.gt,
+    'gt':               operator.gt,
+    'greaterthan':      operator.gt,
+    'ge':               operator.ge,
+    '>=':               operator.ge,
+    '<':                operator.lt,
+    'lt':               operator.lt,
+    'lessthan':         operator.lt,
+    '<=':               operator.le,
+    'le':               operator.le,
+}

cement/cli/contrib/jinja2/utils.py

@@ -0,0 +1,647 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.utils
+    ~~~~~~~~~~~~
+
+    Utility functions.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD, see LICENSE for more details.
+"""
+import re
+import json
+import errno
+from collections import deque
+from threading import Lock
+from jinja2._compat import text_type, string_types, implements_iterator, \
+     url_quote
+
+
+_word_split_re = re.compile(r'(\s+)')
+_punctuation_re = re.compile(
+    '^(?P<lead>(?:%s)*)(?P<middle>.*?)(?P<trail>(?:%s)*)$' % (
+        '|'.join(map(re.escape, ('(', '<', '&lt;'))),
+        '|'.join(map(re.escape, ('.', ',', ')', '>', '\n', '&gt;')))
+    )
+)
+_simple_email_re = re.compile(r'^\S+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9._-]+$')
+_striptags_re = re.compile(r'(<!--.*?-->|<[^>]*>)')
+_entity_re = re.compile(r'&([^;]+);')
+_letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+_digits = '0123456789'
+
+# special singleton representing missing values for the runtime
+missing = type('MissingType', (), {'__repr__': lambda x: 'missing'})()
+
+# internal code
+internal_code = set()
+
+concat = u''.join
+
+_slash_escape = '\\/' not in json.dumps('/')
+
+
+def contextfunction(f):
+    """This decorator can be used to mark a function or method context callable.
+    A context callable is passed the active :class:`Context` as first argument when
+    called from the template.  This is useful if a function wants to get access
+    to the context or functions provided on the context object.  For example
+    a function that returns a sorted list of template variables the current
+    template exports could look like this::
+
+        @contextfunction
+        def get_exported_names(context):
+            return sorted(context.exported_vars)
+    """
+    f.contextfunction = True
+    return f
+
+
+def evalcontextfunction(f):
+    """This decorator can be used to mark a function or method as an eval
+    context callable.  This is similar to the :func:`contextfunction`
+    but instead of passing the context, an evaluation context object is
+    passed.  For more information about the eval context, see
+    :ref:`eval-context`.
+
+    .. versionadded:: 2.4
+    """
+    f.evalcontextfunction = True
+    return f
+
+
+def environmentfunction(f):
+    """This decorator can be used to mark a function or method as environment
+    callable.  This decorator works exactly like the :func:`contextfunction`
+    decorator just that the first argument is the active :class:`Environment`
+    and not context.
+    """
+    f.environmentfunction = True
+    return f
+
+
+def internalcode(f):
+    """Marks the function as internally used"""
+    internal_code.add(f.__code__)
+    return f
+
+
+def is_undefined(obj):
+    """Check if the object passed is undefined.  This does nothing more than
+    performing an instance check against :class:`Undefined` but looks nicer.
+    This can be used for custom filters or tests that want to react to
+    undefined variables.  For example a custom default filter can look like
+    this::
+
+        def default(var, default=''):
+            if is_undefined(var):
+                return default
+            return var
+    """
+    from jinja2.runtime import Undefined
+    return isinstance(obj, Undefined)
+
+
+def consume(iterable):
+    """Consumes an iterable without doing anything with it."""
+    for event in iterable:
+        pass
+
+
+def clear_caches():
+    """Jinja2 keeps internal caches for environments and lexers.  These are
+    used so that Jinja2 doesn't have to recreate environments and lexers all
+    the time.  Normally you don't have to care about that but if you are
+    measuring memory consumption you may want to clean the caches.
+    """
+    from jinja2.environment import _spontaneous_environments
+    from jinja2.lexer import _lexer_cache
+    _spontaneous_environments.clear()
+    _lexer_cache.clear()
+
+
+def import_string(import_name, silent=False):
+    """Imports an object based on a string.  This is useful if you want to
+    use import paths as endpoints or something similar.  An import path can
+    be specified either in dotted notation (``xml.sax.saxutils.escape``)
+    or with a colon as object delimiter (``xml.sax.saxutils:escape``).
+
+    If the `silent` is True the return value will be `None` if the import
+    fails.
+
+    :return: imported object
+    """
+    try:
+        if ':' in import_name:
+            module, obj = import_name.split(':', 1)
+        elif '.' in import_name:
+            items = import_name.split('.')
+            module = '.'.join(items[:-1])
+            obj = items[-1]
+        else:
+            return __import__(import_name)
+        return getattr(__import__(module, None, None, [obj]), obj)
+    except (ImportError, AttributeError):
+        if not silent:
+            raise
+
+
+def open_if_exists(filename, mode='rb'):
+    """Returns a file descriptor for the filename if that file exists,
+    otherwise `None`.
+    """
+    try:
+        return open(filename, mode)
+    except IOError as e:
+        if e.errno not in (errno.ENOENT, errno.EISDIR, errno.EINVAL):
+            raise
+
+
+def object_type_repr(obj):
+    """Returns the name of the object's type.  For some recognized
+    singletons the name of the object is returned instead. (For
+    example for `None` and `Ellipsis`).
+    """
+    if obj is None:
+        return 'None'
+    elif obj is Ellipsis:
+        return 'Ellipsis'
+    # __builtin__ in 2.x, builtins in 3.x
+    if obj.__class__.__module__ in ('__builtin__', 'builtins'):
+        name = obj.__class__.__name__
+    else:
+        name = obj.__class__.__module__ + '.' + obj.__class__.__name__
+    return '%s object' % name
+
+
+def pformat(obj, verbose=False):
+    """Prettyprint an object.  Either use the `pretty` library or the
+    builtin `pprint`.
+    """
+    try:
+        from pretty import pretty
+        return pretty(obj, verbose=verbose)
+    except ImportError:
+        from pprint import pformat
+        return pformat(obj)
+
+
+def urlize(text, trim_url_limit=None, rel=None, target=None):
+    """Converts any URLs in text into clickable links. Works on http://,
+    https:// and www. links. Links can have trailing punctuation (periods,
+    commas, close-parens) and leading punctuation (opening parens) and
+    it'll still do the right thing.
+
+    If trim_url_limit is not None, the URLs in link text will be limited
+    to trim_url_limit characters.
+
+    If nofollow is True, the URLs in link text will get a rel="nofollow"
+    attribute.
+
+    If target is not None, a target attribute will be added to the link.
+    """
+    trim_url = lambda x, limit=trim_url_limit: limit is not None \
+                         and (x[:limit] + (len(x) >=limit and '...'
+                         or '')) or x
+    words = _word_split_re.split(text_type(escape(text)))
+    rel_attr = rel and ' rel="%s"' % text_type(escape(rel)) or ''
+    target_attr = target and ' target="%s"' % escape(target) or ''
+
+    for i, word in enumerate(words):
+        match = _punctuation_re.match(word)
+        if match:
+            lead, middle, trail = match.groups()
+            if middle.startswith('www.') or (
+                '@' not in middle and
+                not middle.startswith('http://') and
+                not middle.startswith('https://') and
+                len(middle) > 0 and
+                middle[0] in _letters + _digits and (
+                    middle.endswith('.org') or
+                    middle.endswith('.net') or
+                    middle.endswith('.com')
+                )):
+                middle = '<a href="http://%s"%s%s>%s</a>' % (middle,
+                    rel_attr, target_attr, trim_url(middle))
+            if middle.startswith('http://') or \
+               middle.startswith('https://'):
+                middle = '<a href="%s"%s%s>%s</a>' % (middle,
+                    rel_attr, target_attr, trim_url(middle))
+            if '@' in middle and not middle.startswith('www.') and \
+               not ':' in middle and _simple_email_re.match(middle):
+                middle = '<a href="mailto:%s">%s</a>' % (middle, middle)
+            if lead + middle + trail != word:
+                words[i] = lead + middle + trail
+    return u''.join(words)
+
+
+def generate_lorem_ipsum(n=5, html=True, min=20, max=100):
+    """Generate some lorem ipsum for the template."""
+    from jinja2.constants import LOREM_IPSUM_WORDS
+    from random import choice, randrange
+    words = LOREM_IPSUM_WORDS.split()
+    result = []
+
+    for _ in range(n):
+        next_capitalized = True
+        last_comma = last_fullstop = 0
+        word = None
+        last = None
+        p = []
+
+        # each paragraph contains out of 20 to 100 words.
+        for idx, _ in enumerate(range(randrange(min, max))):
+            while True:
+                word = choice(words)
+                if word != last:
+                    last = word
+                    break
+            if next_capitalized:
+                word = word.capitalize()
+                next_capitalized = False
+            # add commas
+            if idx - randrange(3, 8) > last_comma:
+                last_comma = idx
+                last_fullstop += 2
+                word += ','
+            # add end of sentences
+            if idx - randrange(10, 20) > last_fullstop:
+                last_comma = last_fullstop = idx
+                word += '.'
+                next_capitalized = True
+            p.append(word)
+
+        # ensure that the paragraph ends with a dot.
+        p = u' '.join(p)
+        if p.endswith(','):
+            p = p[:-1] + '.'
+        elif not p.endswith('.'):
+            p += '.'
+        result.append(p)
+
+    if not html:
+        return u'\n\n'.join(result)
+    return Markup(u'\n'.join(u'<p>%s</p>' % escape(x) for x in result))
+
+
+def unicode_urlencode(obj, charset='utf-8', for_qs=False):
+    """URL escapes a single bytestring or unicode string with the
+    given charset if applicable to URL safe quoting under all rules
+    that need to be considered under all supported Python versions.
+
+    If non strings are provided they are converted to their unicode
+    representation first.
+    """
+    if not isinstance(obj, string_types):
+        obj = text_type(obj)
+    if isinstance(obj, text_type):
+        obj = obj.encode(charset)
+    safe = not for_qs and b'/' or b''
+    rv = text_type(url_quote(obj, safe))
+    if for_qs:
+        rv = rv.replace('%20', '+')
+    return rv
+
+
+class LRUCache(object):
+    """A simple LRU Cache implementation."""
+
+    # this is fast for small capacities (something below 1000) but doesn't
+    # scale.  But as long as it's only used as storage for templates this
+    # won't do any harm.
+
+    def __init__(self, capacity):
+        self.capacity = capacity
+        self._mapping = {}
+        self._queue = deque()
+        self._postinit()
+
+    def _postinit(self):
+        # alias all queue methods for faster lookup
+        self._popleft = self._queue.popleft
+        self._pop = self._queue.pop
+        self._remove = self._queue.remove
+        self._wlock = Lock()
+        self._append = self._queue.append
+
+    def __getstate__(self):
+        return {
+            'capacity':     self.capacity,
+            '_mapping':     self._mapping,
+            '_queue':       self._queue
+        }
+
+    def __setstate__(self, d):
+        self.__dict__.update(d)
+        self._postinit()
+
+    def __getnewargs__(self):
+        return (self.capacity,)
+
+    def copy(self):
+        """Return a shallow copy of the instance."""
+        rv = self.__class__(self.capacity)
+        rv._mapping.update(self._mapping)
+        rv._queue = deque(self._queue)
+        return rv
+
+    def get(self, key, default=None):
+        """Return an item from the cache dict or `default`"""
+        try:
+            return self[key]
+        except KeyError:
+            return default
+
+    def setdefault(self, key, default=None):
+        """Set `default` if the key is not in the cache otherwise
+        leave unchanged. Return the value of this key.
+        """
+        self._wlock.acquire()
+        try:
+            try:
+                return self[key]
+            except KeyError:
+                self[key] = default
+                return default
+        finally:
+            self._wlock.release()
+
+    def clear(self):
+        """Clear the cache."""
+        self._wlock.acquire()
+        try:
+            self._mapping.clear()
+            self._queue.clear()
+        finally:
+            self._wlock.release()
+
+    def __contains__(self, key):
+        """Check if a key exists in this cache."""
+        return key in self._mapping
+
+    def __len__(self):
+        """Return the current size of the cache."""
+        return len(self._mapping)
+
+    def __repr__(self):
+        return '<%s %r>' % (
+            self.__class__.__name__,
+            self._mapping
+        )
+
+    def __getitem__(self, key):
+        """Get an item from the cache. Moves the item up so that it has the
+        highest priority then.
+
+        Raise a `KeyError` if it does not exist.
+        """
+        self._wlock.acquire()
+        try:
+            rv = self._mapping[key]
+            if self._queue[-1] != key:
+                try:
+                    self._remove(key)
+                except ValueError:
+                    # if something removed the key from the container
+                    # when we read, ignore the ValueError that we would
+                    # get otherwise.
+                    pass
+                self._append(key)
+            return rv
+        finally:
+            self._wlock.release()
+
+    def __setitem__(self, key, value):
+        """Sets the value for an item. Moves the item up so that it
+        has the highest priority then.
+        """
+        self._wlock.acquire()
+        try:
+            if key in self._mapping:
+                self._remove(key)
+            elif len(self._mapping) == self.capacity:
+                del self._mapping[self._popleft()]
+            self._append(key)
+            self._mapping[key] = value
+        finally:
+            self._wlock.release()
+
+    def __delitem__(self, key):
+        """Remove an item from the cache dict.
+        Raise a `KeyError` if it does not exist.
+        """
+        self._wlock.acquire()
+        try:
+            del self._mapping[key]
+            try:
+                self._remove(key)
+            except ValueError:
+                # __getitem__ is not locked, it might happen
+                pass
+        finally:
+            self._wlock.release()
+
+    def items(self):
+        """Return a list of items."""
+        result = [(key, self._mapping[key]) for key in list(self._queue)]
+        result.reverse()
+        return result
+
+    def iteritems(self):
+        """Iterate over all items."""
+        return iter(self.items())
+
+    def values(self):
+        """Return a list of all values."""
+        return [x[1] for x in self.items()]
+
+    def itervalue(self):
+        """Iterate over all values."""
+        return iter(self.values())
+
+    def keys(self):
+        """Return a list of all keys ordered by most recent usage."""
+        return list(self)
+
+    def iterkeys(self):
+        """Iterate over all keys in the cache dict, ordered by
+        the most recent usage.
+        """
+        return reversed(tuple(self._queue))
+
+    __iter__ = iterkeys
+
+    def __reversed__(self):
+        """Iterate over the values in the cache dict, oldest items
+        coming first.
+        """
+        return iter(tuple(self._queue))
+
+    __copy__ = copy
+
+
+# register the LRU cache as mutable mapping if possible
+try:
+    from collections import MutableMapping
+    MutableMapping.register(LRUCache)
+except ImportError:
+    pass
+
+
+def select_autoescape(enabled_extensions=('html', 'htm', 'xml'),
+                      disabled_extensions=(),
+                      default_for_string=True,
+                      default=False):
+    """Intelligently sets the initial value of autoescaping based on the
+    filename of the template.  This is the recommended way to configure
+    autoescaping if you do not want to write a custom function yourself.
+
+    If you want to enable it for all templates created from strings or
+    for all templates with `.html` and `.xml` extensions::
+
+        from jinja2 import Environment, select_autoescape
+        env = Environment(autoescape=select_autoescape(
+            enabled_extensions=('html', 'xml'),
+            default_for_string=True,
+        ))
+
+    Example configuration to turn it on at all times except if the template
+    ends with `.txt`::
+
+        from jinja2 import Environment, select_autoescape
+        env = Environment(autoescape=select_autoescape(
+            disabled_extensions=('txt',),
+            default_for_string=True,
+            default=True,
+        ))
+
+    The `enabled_extensions` is an iterable of all the extensions that
+    autoescaping should be enabled for.  Likewise `disabled_extensions` is
+    a list of all templates it should be disabled for.  If a template is
+    loaded from a string then the default from `default_for_string` is used.
+    If nothing matches then the initial value of autoescaping is set to the
+    value of `default`.
+
+    For security reasons this function operates case insensitive.
+
+    .. versionadded:: 2.9
+    """
+    enabled_patterns = tuple('.' + x.lstrip('.').lower()
+                             for x in enabled_extensions)
+    disabled_patterns = tuple('.' + x.lstrip('.').lower()
+                              for x in disabled_extensions)
+    def autoescape(template_name):
+        if template_name is None:
+            return default_for_string
+        template_name = template_name.lower()
+        if template_name.endswith(enabled_patterns):
+            return True
+        if template_name.endswith(disabled_patterns):
+            return False
+        return default
+    return autoescape
+
+
+def htmlsafe_json_dumps(obj, dumper=None, **kwargs):
+    """Works exactly like :func:`dumps` but is safe for use in ``<script>``
+    tags.  It accepts the same arguments and returns a JSON string.  Note that
+    this is available in templates through the ``|tojson`` filter which will
+    also mark the result as safe.  Due to how this function escapes certain
+    characters this is safe even if used outside of ``<script>`` tags.
+
+    The following characters are escaped in strings:
+
+    -   ``<``
+    -   ``>``
+    -   ``&``
+    -   ``'``
+
+    This makes it safe to embed such strings in any place in HTML with the
+    notable exception of double quoted attributes.  In that case single
+    quote your attributes or HTML escape it in addition.
+    """
+    if dumper is None:
+        dumper = json.dumps
+    rv = dumper(obj, **kwargs) \
+        .replace(u'<', u'\\u003c') \
+        .replace(u'>', u'\\u003e') \
+        .replace(u'&', u'\\u0026') \
+        .replace(u"'", u'\\u0027')
+    return Markup(rv)
+
+
+@implements_iterator
+class Cycler(object):
+    """A cycle helper for templates."""
+
+    def __init__(self, *items):
+        if not items:
+            raise RuntimeError('at least one item has to be provided')
+        self.items = items
+        self.reset()
+
+    def reset(self):
+        """Resets the cycle."""
+        self.pos = 0
+
+    @property
+    def current(self):
+        """Returns the current item."""
+        return self.items[self.pos]
+
+    def next(self):
+        """Goes one item ahead and returns it."""
+        rv = self.current
+        self.pos = (self.pos + 1) % len(self.items)
+        return rv
+
+    __next__ = next
+
+
+class Joiner(object):
+    """A joining helper for templates."""
+
+    def __init__(self, sep=u', '):
+        self.sep = sep
+        self.used = False
+
+    def __call__(self):
+        if not self.used:
+            self.used = True
+            return u''
+        return self.sep
+
+
+class Namespace(object):
+    """A namespace object that can hold arbitrary attributes.  It may be
+    initialized from a dictionary or with keyword argments."""
+
+    def __init__(*args, **kwargs):
+        self, args = args[0], args[1:]
+        self.__attrs = dict(*args, **kwargs)
+
+    def __getattribute__(self, name):
+        if name == '_Namespace__attrs':
+            return object.__getattribute__(self, name)
+        try:
+            return self.__attrs[name]
+        except KeyError:
+            raise AttributeError(name)
+
+    def __setitem__(self, name, value):
+        self.__attrs[name] = value
+
+    def __repr__(self):
+        return '<Namespace %r>' % self.__attrs
+
+
+# does this python version support async for in and async generators?
+try:
+    exec('async def _():\n async for _ in ():\n  yield _')
+    have_async_gen = True
+except SyntaxError:
+    have_async_gen = False
+
+
+# Imported here because that's where it was in the past
+from markupsafe import Markup, escape, soft_unicode

cement/cli/contrib/jinja2/visitor.py

@@ -0,0 +1,87 @@
+# -*- coding: utf-8 -*-
+"""
+    jinja2.visitor
+    ~~~~~~~~~~~~~~
+
+    This module implements a visitor for the nodes.
+
+    :copyright: (c) 2017 by the Jinja Team.
+    :license: BSD.
+"""
+from jinja2.nodes import Node
+
+
+class NodeVisitor(object):
+    """Walks the abstract syntax tree and call visitor functions for every
+    node found.  The visitor functions may return values which will be
+    forwarded by the `visit` method.
+
+    Per default the visitor functions for the nodes are ``'visit_'`` +
+    class name of the node.  So a `TryFinally` node visit function would
+    be `visit_TryFinally`.  This behavior can be changed by overriding
+    the `get_visitor` function.  If no visitor function exists for a node
+    (return value `None`) the `generic_visit` visitor is used instead.
+    """
+
+    def get_visitor(self, node):
+        """Return the visitor function for this node or `None` if no visitor
+        exists for this node.  In that case the generic visit function is
+        used instead.
+        """
+        method = 'visit_' + node.__class__.__name__
+        return getattr(self, method, None)
+
+    def visit(self, node, *args, **kwargs):
+        """Visit a node."""
+        f = self.get_visitor(node)
+        if f is not None:
+            return f(node, *args, **kwargs)
+        return self.generic_visit(node, *args, **kwargs)
+
+    def generic_visit(self, node, *args, **kwargs):
+        """Called if no explicit visitor function exists for a node."""
+        for node in node.iter_child_nodes():
+            self.visit(node, *args, **kwargs)
+
+
+class NodeTransformer(NodeVisitor):
+    """Walks the abstract syntax tree and allows modifications of nodes.
+
+    The `NodeTransformer` will walk the AST and use the return value of the
+    visitor functions to replace or remove the old node.  If the return
+    value of the visitor function is `None` the node will be removed
+    from the previous location otherwise it's replaced with the return
+    value.  The return value may be the original node in which case no
+    replacement takes place.
+    """
+
+    def generic_visit(self, node, *args, **kwargs):
+        for field, old_value in node.iter_fields():
+            if isinstance(old_value, list):
+                new_values = []
+                for value in old_value:
+                    if isinstance(value, Node):
+                        value = self.visit(value, *args, **kwargs)
+                        if value is None:
+                            continue
+                        elif not isinstance(value, Node):
+                            new_values.extend(value)
+                            continue
+                    new_values.append(value)
+                old_value[:] = new_values
+            elif isinstance(old_value, Node):
+                new_node = self.visit(old_value, *args, **kwargs)
+                if new_node is None:
+                    delattr(node, field)
+                else:
+                    setattr(node, field, new_node)
+        return node
+
+    def visit_list(self, node, *args, **kwargs):
+        """As transformers may return lists in some places this method
+        can be used to enforce a list as return value.
+        """
+        rv = self.visit(node, *args, **kwargs)
+        if not isinstance(rv, list):
+            rv = [rv]
+        return rv

cement/cli/contrib/yaml/__init__.py

@@ -0,0 +1,312 @@
+
+from .error import *
+
+from .tokens import *
+from .events import *
+from .nodes import *
+
+from .loader import *
+from .dumper import *
+
+__version__ = '3.12'
+try:
+    from .cyaml import *
+    __with_libyaml__ = True
+except ImportError:
+    __with_libyaml__ = False
+
+import io
+
+def scan(stream, Loader=Loader):
+    """
+    Scan a YAML stream and produce scanning tokens.
+    """
+    loader = Loader(stream)
+    try:
+        while loader.check_token():
+            yield loader.get_token()
+    finally:
+        loader.dispose()
+
+def parse(stream, Loader=Loader):
+    """
+    Parse a YAML stream and produce parsing events.
+    """
+    loader = Loader(stream)
+    try:
+        while loader.check_event():
+            yield loader.get_event()
+    finally:
+        loader.dispose()
+
+def compose(stream, Loader=Loader):
+    """
+    Parse the first YAML document in a stream
+    and produce the corresponding representation tree.
+    """
+    loader = Loader(stream)
+    try:
+        return loader.get_single_node()
+    finally:
+        loader.dispose()
+
+def compose_all(stream, Loader=Loader):
+    """
+    Parse all YAML documents in a stream
+    and produce corresponding representation trees.
+    """
+    loader = Loader(stream)
+    try:
+        while loader.check_node():
+            yield loader.get_node()
+    finally:
+        loader.dispose()
+
+def load(stream, Loader=Loader):
+    """
+    Parse the first YAML document in a stream
+    and produce the corresponding Python object.
+    """
+    loader = Loader(stream)
+    try:
+        return loader.get_single_data()
+    finally:
+        loader.dispose()
+
+def load_all(stream, Loader=Loader):
+    """
+    Parse all YAML documents in a stream
+    and produce corresponding Python objects.
+    """
+    loader = Loader(stream)
+    try:
+        while loader.check_data():
+            yield loader.get_data()
+    finally:
+        loader.dispose()
+
+def safe_load(stream):
+    """
+    Parse the first YAML document in a stream
+    and produce the corresponding Python object.
+    Resolve only basic YAML tags.
+    """
+    return load(stream, SafeLoader)
+
+def safe_load_all(stream):
+    """
+    Parse all YAML documents in a stream
+    and produce corresponding Python objects.
+    Resolve only basic YAML tags.
+    """
+    return load_all(stream, SafeLoader)
+
+def emit(events, stream=None, Dumper=Dumper,
+        canonical=None, indent=None, width=None,
+        allow_unicode=None, line_break=None):
+    """
+    Emit YAML parsing events into a stream.
+    If stream is None, return the produced string instead.
+    """
+    getvalue = None
+    if stream is None:
+        stream = io.StringIO()
+        getvalue = stream.getvalue
+    dumper = Dumper(stream, canonical=canonical, indent=indent, width=width,
+            allow_unicode=allow_unicode, line_break=line_break)
+    try:
+        for event in events:
+            dumper.emit(event)
+    finally:
+        dumper.dispose()
+    if getvalue:
+        return getvalue()
+
+def serialize_all(nodes, stream=None, Dumper=Dumper,
+        canonical=None, indent=None, width=None,
+        allow_unicode=None, line_break=None,
+        encoding=None, explicit_start=None, explicit_end=None,
+        version=None, tags=None):
+    """
+    Serialize a sequence of representation trees into a YAML stream.
+    If stream is None, return the produced string instead.
+    """
+    getvalue = None
+    if stream is None:
+        if encoding is None:
+            stream = io.StringIO()
+        else:
+            stream = io.BytesIO()
+        getvalue = stream.getvalue
+    dumper = Dumper(stream, canonical=canonical, indent=indent, width=width,
+            allow_unicode=allow_unicode, line_break=line_break,
+            encoding=encoding, version=version, tags=tags,
+            explicit_start=explicit_start, explicit_end=explicit_end)
+    try:
+        dumper.open()
+        for node in nodes:
+            dumper.serialize(node)
+        dumper.close()
+    finally:
+        dumper.dispose()
+    if getvalue:
+        return getvalue()
+
+def serialize(node, stream=None, Dumper=Dumper, **kwds):
+    """
+    Serialize a representation tree into a YAML stream.
+    If stream is None, return the produced string instead.
+    """
+    return serialize_all([node], stream, Dumper=Dumper, **kwds)
+
+def dump_all(documents, stream=None, Dumper=Dumper,
+        default_style=None, default_flow_style=None,
+        canonical=None, indent=None, width=None,
+        allow_unicode=None, line_break=None,
+        encoding=None, explicit_start=None, explicit_end=None,
+        version=None, tags=None):
+    """
+    Serialize a sequence of Python objects into a YAML stream.
+    If stream is None, return the produced string instead.
+    """
+    getvalue = None
+    if stream is None:
+        if encoding is None:
+            stream = io.StringIO()
+        else:
+            stream = io.BytesIO()
+        getvalue = stream.getvalue
+    dumper = Dumper(stream, default_style=default_style,
+            default_flow_style=default_flow_style,
+            canonical=canonical, indent=indent, width=width,
+            allow_unicode=allow_unicode, line_break=line_break,
+            encoding=encoding, version=version, tags=tags,
+            explicit_start=explicit_start, explicit_end=explicit_end)
+    try:
+        dumper.open()
+        for data in documents:
+            dumper.represent(data)
+        dumper.close()
+    finally:
+        dumper.dispose()
+    if getvalue:
+        return getvalue()
+
+def dump(data, stream=None, Dumper=Dumper, **kwds):
+    """
+    Serialize a Python object into a YAML stream.
+    If stream is None, return the produced string instead.
+    """
+    return dump_all([data], stream, Dumper=Dumper, **kwds)
+
+def safe_dump_all(documents, stream=None, **kwds):
+    """
+    Serialize a sequence of Python objects into a YAML stream.
+    Produce only basic YAML tags.
+    If stream is None, return the produced string instead.
+    """
+    return dump_all(documents, stream, Dumper=SafeDumper, **kwds)
+
+def safe_dump(data, stream=None, **kwds):
+    """
+    Serialize a Python object into a YAML stream.
+    Produce only basic YAML tags.
+    If stream is None, return the produced string instead.
+    """
+    return dump_all([data], stream, Dumper=SafeDumper, **kwds)
+
+def add_implicit_resolver(tag, regexp, first=None,
+        Loader=Loader, Dumper=Dumper):
+    """
+    Add an implicit scalar detector.
+    If an implicit scalar value matches the given regexp,
+    the corresponding tag is assigned to the scalar.
+    first is a sequence of possible initial characters or None.
+    """
+    Loader.add_implicit_resolver(tag, regexp, first)
+    Dumper.add_implicit_resolver(tag, regexp, first)
+
+def add_path_resolver(tag, path, kind=None, Loader=Loader, Dumper=Dumper):
+    """
+    Add a path based resolver for the given tag.
+    A path is a list of keys that forms a path
+    to a node in the representation tree.
+    Keys can be string values, integers, or None.
+    """
+    Loader.add_path_resolver(tag, path, kind)
+    Dumper.add_path_resolver(tag, path, kind)
+
+def add_constructor(tag, constructor, Loader=Loader):
+    """
+    Add a constructor for the given tag.
+    Constructor is a function that accepts a Loader instance
+    and a node object and produces the corresponding Python object.
+    """
+    Loader.add_constructor(tag, constructor)
+
+def add_multi_constructor(tag_prefix, multi_constructor, Loader=Loader):
+    """
+    Add a multi-constructor for the given tag prefix.
+    Multi-constructor is called for a node if its tag starts with tag_prefix.
+    Multi-constructor accepts a Loader instance, a tag suffix,
+    and a node object and produces the corresponding Python object.
+    """
+    Loader.add_multi_constructor(tag_prefix, multi_constructor)
+
+def add_representer(data_type, representer, Dumper=Dumper):
+    """
+    Add a representer for the given type.
+    Representer is a function accepting a Dumper instance
+    and an instance of the given data type
+    and producing the corresponding representation node.
+    """
+    Dumper.add_representer(data_type, representer)
+
+def add_multi_representer(data_type, multi_representer, Dumper=Dumper):
+    """
+    Add a representer for the given type.
+    Multi-representer is a function accepting a Dumper instance
+    and an instance of the given data type or subtype
+    and producing the corresponding representation node.
+    """
+    Dumper.add_multi_representer(data_type, multi_representer)
+
+class YAMLObjectMetaclass(type):
+    """
+    The metaclass for YAMLObject.
+    """
+    def __init__(cls, name, bases, kwds):
+        super(YAMLObjectMetaclass, cls).__init__(name, bases, kwds)
+        if 'yaml_tag' in kwds and kwds['yaml_tag'] is not None:
+            cls.yaml_loader.add_constructor(cls.yaml_tag, cls.from_yaml)
+            cls.yaml_dumper.add_representer(cls, cls.to_yaml)
+
+class YAMLObject(metaclass=YAMLObjectMetaclass):
+    """
+    An object that can dump itself to a YAML stream
+    and load itself from a YAML stream.
+    """
+
+    __slots__ = ()  # no direct instantiation, so allow immutable subclasses
+
+    yaml_loader = Loader
+    yaml_dumper = Dumper
+
+    yaml_tag = None
+    yaml_flow_style = None
+
+    @classmethod
+    def from_yaml(cls, loader, node):
+        """
+        Convert a representation node to a Python object.
+        """
+        return loader.construct_yaml_object(node, cls)
+
+    @classmethod
+    def to_yaml(cls, dumper, data):
+        """
+        Convert a Python object to a representation node.
+        """
+        return dumper.represent_yaml_object(cls.yaml_tag, data, cls,
+                flow_style=cls.yaml_flow_style)
+

cement/cli/contrib/yaml/composer.py

@@ -0,0 +1,139 @@
+
+__all__ = ['Composer', 'ComposerError']
+
+from .error import MarkedYAMLError
+from .events import *
+from .nodes import *
+
+class ComposerError(MarkedYAMLError):
+    pass
+
+class Composer:
+
+    def __init__(self):
+        self.anchors = {}
+
+    def check_node(self):
+        # Drop the STREAM-START event.
+        if self.check_event(StreamStartEvent):
+            self.get_event()
+
+        # If there are more documents available?
+        return not self.check_event(StreamEndEvent)
+
+    def get_node(self):
+        # Get the root node of the next document.
+        if not self.check_event(StreamEndEvent):
+            return self.compose_document()
+
+    def get_single_node(self):
+        # Drop the STREAM-START event.
+        self.get_event()
+
+        # Compose a document if the stream is not empty.
+        document = None
+        if not self.check_event(StreamEndEvent):
+            document = self.compose_document()
+
+        # Ensure that the stream contains no more documents.
+        if not self.check_event(StreamEndEvent):
+            event = self.get_event()
+            raise ComposerError("expected a single document in the stream",
+                    document.start_mark, "but found another document",
+                    event.start_mark)
+
+        # Drop the STREAM-END event.
+        self.get_event()
+
+        return document
+
+    def compose_document(self):
+        # Drop the DOCUMENT-START event.
+        self.get_event()
+
+        # Compose the root node.
+        node = self.compose_node(None, None)
+
+        # Drop the DOCUMENT-END event.
+        self.get_event()
+
+        self.anchors = {}
+        return node
+
+    def compose_node(self, parent, index):
+        if self.check_event(AliasEvent):
+            event = self.get_event()
+            anchor = event.anchor
+            if anchor not in self.anchors:
+                raise ComposerError(None, None, "found undefined alias %r"
+                        % anchor, event.start_mark)
+            return self.anchors[anchor]
+        event = self.peek_event()
+        anchor = event.anchor
+        if anchor is not None:
+            if anchor in self.anchors:
+                raise ComposerError("found duplicate anchor %r; first occurence"
+                        % anchor, self.anchors[anchor].start_mark,
+                        "second occurence", event.start_mark)
+        self.descend_resolver(parent, index)
+        if self.check_event(ScalarEvent):
+            node = self.compose_scalar_node(anchor)
+        elif self.check_event(SequenceStartEvent):
+            node = self.compose_sequence_node(anchor)
+        elif self.check_event(MappingStartEvent):
+            node = self.compose_mapping_node(anchor)
+        self.ascend_resolver()
+        return node
+
+    def compose_scalar_node(self, anchor):
+        event = self.get_event()
+        tag = event.tag
+        if tag is None or tag == '!':
+            tag = self.resolve(ScalarNode, event.value, event.implicit)
+        node = ScalarNode(tag, event.value,
+                event.start_mark, event.end_mark, style=event.style)
+        if anchor is not None:
+            self.anchors[anchor] = node
+        return node
+
+    def compose_sequence_node(self, anchor):
+        start_event = self.get_event()
+        tag = start_event.tag
+        if tag is None or tag == '!':
+            tag = self.resolve(SequenceNode, None, start_event.implicit)
+        node = SequenceNode(tag, [],
+                start_event.start_mark, None,
+                flow_style=start_event.flow_style)
+        if anchor is not None:
+            self.anchors[anchor] = node
+        index = 0
+        while not self.check_event(SequenceEndEvent):
+            node.value.append(self.compose_node(node, index))
+            index += 1
+        end_event = self.get_event()
+        node.end_mark = end_event.end_mark
+        return node
+
+    def compose_mapping_node(self, anchor):
+        start_event = self.get_event()
+        tag = start_event.tag
+        if tag is None or tag == '!':
+            tag = self.resolve(MappingNode, None, start_event.implicit)
+        node = MappingNode(tag, [],
+                start_event.start_mark, None,
+                flow_style=start_event.flow_style)
+        if anchor is not None:
+            self.anchors[anchor] = node
+        while not self.check_event(MappingEndEvent):
+            #key_event = self.peek_event()
+            item_key = self.compose_node(node, None)
+            #if item_key in node.value:
+            #    raise ComposerError("while composing a mapping", start_event.start_mark,
+            #            "found duplicate key", key_event.start_mark)
+            item_value = self.compose_node(node, item_key)
+            #node.value[item_key] = item_value
+            node.value.append((item_key, item_value))
+        end_event = self.get_event()
+        node.end_mark = end_event.end_mark
+        return node
+

cement/cli/contrib/yaml/constructor.py

@@ -0,0 +1,686 @@
+
+__all__ = ['BaseConstructor', 'SafeConstructor', 'Constructor',
+    'ConstructorError']
+
+from .error import *
+from .nodes import *
+
+import collections, datetime, base64, binascii, re, sys, types
+
+class ConstructorError(MarkedYAMLError):
+    pass
+
+class BaseConstructor:
+
+    yaml_constructors = {}
+    yaml_multi_constructors = {}
+
+    def __init__(self):
+        self.constructed_objects = {}
+        self.recursive_objects = {}
+        self.state_generators = []
+        self.deep_construct = False
+
+    def check_data(self):
+        # If there are more documents available?
+        return self.check_node()
+
+    def get_data(self):
+        # Construct and return the next document.
+        if self.check_node():
+            return self.construct_document(self.get_node())
+
+    def get_single_data(self):
+        # Ensure that the stream contains a single document and construct it.
+        node = self.get_single_node()
+        if node is not None:
+            return self.construct_document(node)
+        return None
+
+    def construct_document(self, node):
+        data = self.construct_object(node)
+        while self.state_generators:
+            state_generators = self.state_generators
+            self.state_generators = []
+            for generator in state_generators:
+                for dummy in generator:
+                    pass
+        self.constructed_objects = {}
+        self.recursive_objects = {}
+        self.deep_construct = False
+        return data
+
+    def construct_object(self, node, deep=False):
+        if node in self.constructed_objects:
+            return self.constructed_objects[node]
+        if deep:
+            old_deep = self.deep_construct
+            self.deep_construct = True
+        if node in self.recursive_objects:
+            raise ConstructorError(None, None,
+                    "found unconstructable recursive node", node.start_mark)
+        self.recursive_objects[node] = None
+        constructor = None
+        tag_suffix = None
+        if node.tag in self.yaml_constructors:
+            constructor = self.yaml_constructors[node.tag]
+        else:
+            for tag_prefix in self.yaml_multi_constructors:
+                if node.tag.startswith(tag_prefix):
+                    tag_suffix = node.tag[len(tag_prefix):]
+                    constructor = self.yaml_multi_constructors[tag_prefix]
+                    break
+            else:
+                if None in self.yaml_multi_constructors:
+                    tag_suffix = node.tag
+                    constructor = self.yaml_multi_constructors[None]
+                elif None in self.yaml_constructors:
+                    constructor = self.yaml_constructors[None]
+                elif isinstance(node, ScalarNode):
+                    constructor = self.__class__.construct_scalar
+                elif isinstance(node, SequenceNode):
+                    constructor = self.__class__.construct_sequence
+                elif isinstance(node, MappingNode):
+                    constructor = self.__class__.construct_mapping
+        if tag_suffix is None:
+            data = constructor(self, node)
+        else:
+            data = constructor(self, tag_suffix, node)
+        if isinstance(data, types.GeneratorType):
+            generator = data
+            data = next(generator)
+            if self.deep_construct:
+                for dummy in generator:
+                    pass
+            else:
+                self.state_generators.append(generator)
+        self.constructed_objects[node] = data
+        del self.recursive_objects[node]
+        if deep:
+            self.deep_construct = old_deep
+        return data
+
+    def construct_scalar(self, node):
+        if not isinstance(node, ScalarNode):
+            raise ConstructorError(None, None,
+                    "expected a scalar node, but found %s" % node.id,
+                    node.start_mark)
+        return node.value
+
+    def construct_sequence(self, node, deep=False):
+        if not isinstance(node, SequenceNode):
+            raise ConstructorError(None, None,
+                    "expected a sequence node, but found %s" % node.id,
+                    node.start_mark)
+        return [self.construct_object(child, deep=deep)
+                for child in node.value]
+
+    def construct_mapping(self, node, deep=False):
+        if not isinstance(node, MappingNode):
+            raise ConstructorError(None, None,
+                    "expected a mapping node, but found %s" % node.id,
+                    node.start_mark)
+        mapping = {}
+        for key_node, value_node in node.value:
+            key = self.construct_object(key_node, deep=deep)
+            if not isinstance(key, collections.Hashable):
+                raise ConstructorError("while constructing a mapping", node.start_mark,
+                        "found unhashable key", key_node.start_mark)
+            value = self.construct_object(value_node, deep=deep)
+            mapping[key] = value
+        return mapping
+
+    def construct_pairs(self, node, deep=False):
+        if not isinstance(node, MappingNode):
+            raise ConstructorError(None, None,
+                    "expected a mapping node, but found %s" % node.id,
+                    node.start_mark)
+        pairs = []
+        for key_node, value_node in node.value:
+            key = self.construct_object(key_node, deep=deep)
+            value = self.construct_object(value_node, deep=deep)
+            pairs.append((key, value))
+        return pairs
+
+    @classmethod
+    def add_constructor(cls, tag, constructor):
+        if not 'yaml_constructors' in cls.__dict__:
+            cls.yaml_constructors = cls.yaml_constructors.copy()
+        cls.yaml_constructors[tag] = constructor
+
+    @classmethod
+    def add_multi_constructor(cls, tag_prefix, multi_constructor):
+        if not 'yaml_multi_constructors' in cls.__dict__:
+            cls.yaml_multi_constructors = cls.yaml_multi_constructors.copy()
+        cls.yaml_multi_constructors[tag_prefix] = multi_constructor
+
+class SafeConstructor(BaseConstructor):
+
+    def construct_scalar(self, node):
+        if isinstance(node, MappingNode):
+            for key_node, value_node in node.value:
+                if key_node.tag == 'tag:yaml.org,2002:value':
+                    return self.construct_scalar(value_node)
+        return super().construct_scalar(node)
+
+    def flatten_mapping(self, node):
+        merge = []
+        index = 0
+        while index < len(node.value):
+            key_node, value_node = node.value[index]
+            if key_node.tag == 'tag:yaml.org,2002:merge':
+                del node.value[index]
+                if isinstance(value_node, MappingNode):
+                    self.flatten_mapping(value_node)
+                    merge.extend(value_node.value)
+                elif isinstance(value_node, SequenceNode):
+                    submerge = []
+                    for subnode in value_node.value:
+                        if not isinstance(subnode, MappingNode):
+                            raise ConstructorError("while constructing a mapping",
+                                    node.start_mark,
+                                    "expected a mapping for merging, but found %s"
+                                    % subnode.id, subnode.start_mark)
+                        self.flatten_mapping(subnode)
+                        submerge.append(subnode.value)
+                    submerge.reverse()
+                    for value in submerge:
+                        merge.extend(value)
+                else:
+                    raise ConstructorError("while constructing a mapping", node.start_mark,
+                            "expected a mapping or list of mappings for merging, but found %s"
+                            % value_node.id, value_node.start_mark)
+            elif key_node.tag == 'tag:yaml.org,2002:value':
+                key_node.tag = 'tag:yaml.org,2002:str'
+                index += 1
+            else:
+                index += 1
+        if merge:
+            node.value = merge + node.value
+
+    def construct_mapping(self, node, deep=False):
+        if isinstance(node, MappingNode):
+            self.flatten_mapping(node)
+        return super().construct_mapping(node, deep=deep)
+
+    def construct_yaml_null(self, node):
+        self.construct_scalar(node)
+        return None
+
+    bool_values = {
+        'yes':      True,
+        'no':       False,
+        'true':     True,
+        'false':    False,
+        'on':       True,
+        'off':      False,
+    }
+
+    def construct_yaml_bool(self, node):
+        value = self.construct_scalar(node)
+        return self.bool_values[value.lower()]
+
+    def construct_yaml_int(self, node):
+        value = self.construct_scalar(node)
+        value = value.replace('_', '')
+        sign = +1
+        if value[0] == '-':
+            sign = -1
+        if value[0] in '+-':
+            value = value[1:]
+        if value == '0':
+            return 0
+        elif value.startswith('0b'):
+            return sign*int(value[2:], 2)
+        elif value.startswith('0x'):
+            return sign*int(value[2:], 16)
+        elif value[0] == '0':
+            return sign*int(value, 8)
+        elif ':' in value:
+            digits = [int(part) for part in value.split(':')]
+            digits.reverse()
+            base = 1
+            value = 0
+            for digit in digits:
+                value += digit*base
+                base *= 60
+            return sign*value
+        else:
+            return sign*int(value)
+
+    inf_value = 1e300
+    while inf_value != inf_value*inf_value:
+        inf_value *= inf_value
+    nan_value = -inf_value/inf_value   # Trying to make a quiet NaN (like C99).
+
+    def construct_yaml_float(self, node):
+        value = self.construct_scalar(node)
+        value = value.replace('_', '').lower()
+        sign = +1
+        if value[0] == '-':
+            sign = -1
+        if value[0] in '+-':
+            value = value[1:]
+        if value == '.inf':
+            return sign*self.inf_value
+        elif value == '.nan':
+            return self.nan_value
+        elif ':' in value:
+            digits = [float(part) for part in value.split(':')]
+            digits.reverse()
+            base = 1
+            value = 0.0
+            for digit in digits:
+                value += digit*base
+                base *= 60
+            return sign*value
+        else:
+            return sign*float(value)
+
+    def construct_yaml_binary(self, node):
+        try:
+            value = self.construct_scalar(node).encode('ascii')
+        except UnicodeEncodeError as exc:
+            raise ConstructorError(None, None,
+                    "failed to convert base64 data into ascii: %s" % exc,
+                    node.start_mark)
+        try:
+            if hasattr(base64, 'decodebytes'):
+                return base64.decodebytes(value)
+            else:
+                return base64.decodestring(value)
+        except binascii.Error as exc:
+            raise ConstructorError(None, None,
+                    "failed to decode base64 data: %s" % exc, node.start_mark)
+
+    timestamp_regexp = re.compile(
+            r'''^(?P<year>[0-9][0-9][0-9][0-9])
+                -(?P<month>[0-9][0-9]?)
+                -(?P<day>[0-9][0-9]?)
+                (?:(?:[Tt]|[ \t]+)
+                (?P<hour>[0-9][0-9]?)
+                :(?P<minute>[0-9][0-9])
+                :(?P<second>[0-9][0-9])
+                (?:\.(?P<fraction>[0-9]*))?
+                (?:[ \t]*(?P<tz>Z|(?P<tz_sign>[-+])(?P<tz_hour>[0-9][0-9]?)
+                (?::(?P<tz_minute>[0-9][0-9]))?))?)?$''', re.X)
+
+    def construct_yaml_timestamp(self, node):
+        value = self.construct_scalar(node)
+        match = self.timestamp_regexp.match(node.value)
+        values = match.groupdict()
+        year = int(values['year'])
+        month = int(values['month'])
+        day = int(values['day'])
+        if not values['hour']:
+            return datetime.date(year, month, day)
+        hour = int(values['hour'])
+        minute = int(values['minute'])
+        second = int(values['second'])
+        fraction = 0
+        if values['fraction']:
+            fraction = values['fraction'][:6]
+            while len(fraction) < 6:
+                fraction += '0'
+            fraction = int(fraction)
+        delta = None
+        if values['tz_sign']:
+            tz_hour = int(values['tz_hour'])
+            tz_minute = int(values['tz_minute'] or 0)
+            delta = datetime.timedelta(hours=tz_hour, minutes=tz_minute)
+            if values['tz_sign'] == '-':
+                delta = -delta
+        data = datetime.datetime(year, month, day, hour, minute, second, fraction)
+        if delta:
+            data -= delta
+        return data
+
+    def construct_yaml_omap(self, node):
+        # Note: we do not check for duplicate keys, because it's too
+        # CPU-expensive.
+        omap = []
+        yield omap
+        if not isinstance(node, SequenceNode):
+            raise ConstructorError("while constructing an ordered map", node.start_mark,
+                    "expected a sequence, but found %s" % node.id, node.start_mark)
+        for subnode in node.value:
+            if not isinstance(subnode, MappingNode):
+                raise ConstructorError("while constructing an ordered map", node.start_mark,
+                        "expected a mapping of length 1, but found %s" % subnode.id,
+                        subnode.start_mark)
+            if len(subnode.value) != 1:
+                raise ConstructorError("while constructing an ordered map", node.start_mark,
+                        "expected a single mapping item, but found %d items" % len(subnode.value),
+                        subnode.start_mark)
+            key_node, value_node = subnode.value[0]
+            key = self.construct_object(key_node)
+            value = self.construct_object(value_node)
+            omap.append((key, value))
+
+    def construct_yaml_pairs(self, node):
+        # Note: the same code as `construct_yaml_omap`.
+        pairs = []
+        yield pairs
+        if not isinstance(node, SequenceNode):
+            raise ConstructorError("while constructing pairs", node.start_mark,
+                    "expected a sequence, but found %s" % node.id, node.start_mark)
+        for subnode in node.value:
+            if not isinstance(subnode, MappingNode):
+                raise ConstructorError("while constructing pairs", node.start_mark,
+                        "expected a mapping of length 1, but found %s" % subnode.id,
+                        subnode.start_mark)
+            if len(subnode.value) != 1:
+                raise ConstructorError("while constructing pairs", node.start_mark,
+                        "expected a single mapping item, but found %d items" % len(subnode.value),
+                        subnode.start_mark)
+            key_node, value_node = subnode.value[0]
+            key = self.construct_object(key_node)
+            value = self.construct_object(value_node)
+            pairs.append((key, value))
+
+    def construct_yaml_set(self, node):
+        data = set()
+        yield data
+        value = self.construct_mapping(node)
+        data.update(value)
+
+    def construct_yaml_str(self, node):
+        return self.construct_scalar(node)
+
+    def construct_yaml_seq(self, node):
+        data = []
+        yield data
+        data.extend(self.construct_sequence(node))
+
+    def construct_yaml_map(self, node):
+        data = {}
+        yield data
+        value = self.construct_mapping(node)
+        data.update(value)
+
+    def construct_yaml_object(self, node, cls):
+        data = cls.__new__(cls)
+        yield data
+        if hasattr(data, '__setstate__'):
+            state = self.construct_mapping(node, deep=True)
+            data.__setstate__(state)
+        else:
+            state = self.construct_mapping(node)
+            data.__dict__.update(state)
+
+    def construct_undefined(self, node):
+        raise ConstructorError(None, None,
+                "could not determine a constructor for the tag %r" % node.tag,
+                node.start_mark)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:null',
+        SafeConstructor.construct_yaml_null)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:bool',
+        SafeConstructor.construct_yaml_bool)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:int',
+        SafeConstructor.construct_yaml_int)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:float',
+        SafeConstructor.construct_yaml_float)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:binary',
+        SafeConstructor.construct_yaml_binary)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:timestamp',
+        SafeConstructor.construct_yaml_timestamp)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:omap',
+        SafeConstructor.construct_yaml_omap)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:pairs',
+        SafeConstructor.construct_yaml_pairs)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:set',
+        SafeConstructor.construct_yaml_set)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:str',
+        SafeConstructor.construct_yaml_str)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:seq',
+        SafeConstructor.construct_yaml_seq)
+
+SafeConstructor.add_constructor(
+        'tag:yaml.org,2002:map',
+        SafeConstructor.construct_yaml_map)
+
+SafeConstructor.add_constructor(None,
+        SafeConstructor.construct_undefined)
+
+class Constructor(SafeConstructor):
+
+    def construct_python_str(self, node):
+        return self.construct_scalar(node)
+
+    def construct_python_unicode(self, node):
+        return self.construct_scalar(node)
+
+    def construct_python_bytes(self, node):
+        try:
+            value = self.construct_scalar(node).encode('ascii')
+        except UnicodeEncodeError as exc:
+            raise ConstructorError(None, None,
+                    "failed to convert base64 data into ascii: %s" % exc,
+                    node.start_mark)
+        try:
+            if hasattr(base64, 'decodebytes'):
+                return base64.decodebytes(value)
+            else:
+                return base64.decodestring(value)
+        except binascii.Error as exc:
+            raise ConstructorError(None, None,
+                    "failed to decode base64 data: %s" % exc, node.start_mark)
+
+    def construct_python_long(self, node):
+        return self.construct_yaml_int(node)
+
+    def construct_python_complex(self, node):
+       return complex(self.construct_scalar(node))
+
+    def construct_python_tuple(self, node):
+        return tuple(self.construct_sequence(node))
+
+    def find_python_module(self, name, mark):
+        if not name:
+            raise ConstructorError("while constructing a Python module", mark,
+                    "expected non-empty name appended to the tag", mark)
+        try:
+            __import__(name)
+        except ImportError as exc:
+            raise ConstructorError("while constructing a Python module", mark,
+                    "cannot find module %r (%s)" % (name, exc), mark)
+        return sys.modules[name]
+
+    def find_python_name(self, name, mark):
+        if not name:
+            raise ConstructorError("while constructing a Python object", mark,
+                    "expected non-empty name appended to the tag", mark)
+        if '.' in name:
+            module_name, object_name = name.rsplit('.', 1)
+        else:
+            module_name = 'builtins'
+            object_name = name
+        try:
+            __import__(module_name)
+        except ImportError as exc:
+            raise ConstructorError("while constructing a Python object", mark,
+                    "cannot find module %r (%s)" % (module_name, exc), mark)
+        module = sys.modules[module_name]
+        if not hasattr(module, object_name):
+            raise ConstructorError("while constructing a Python object", mark,
+                    "cannot find %r in the module %r"
+                    % (object_name, module.__name__), mark)
+        return getattr(module, object_name)
+
+    def construct_python_name(self, suffix, node):
+        value = self.construct_scalar(node)
+        if value:
+            raise ConstructorError("while constructing a Python name", node.start_mark,
+                    "expected the empty value, but found %r" % value, node.start_mark)
+        return self.find_python_name(suffix, node.start_mark)
+
+    def construct_python_module(self, suffix, node):
+        value = self.construct_scalar(node)
+        if value:
+            raise ConstructorError("while constructing a Python module", node.start_mark,
+                    "expected the empty value, but found %r" % value, node.start_mark)
+        return self.find_python_module(suffix, node.start_mark)
+
+    def make_python_instance(self, suffix, node,
+            args=None, kwds=None, newobj=False):
+        if not args:
+            args = []
+        if not kwds:
+            kwds = {}
+        cls = self.find_python_name(suffix, node.start_mark)
+        if newobj and isinstance(cls, type):
+            return cls.__new__(cls, *args, **kwds)
+        else:
+            return cls(*args, **kwds)
+
+    def set_python_instance_state(self, instance, state):
+        if hasattr(instance, '__setstate__'):
+            instance.__setstate__(state)
+        else:
+            slotstate = {}
+            if isinstance(state, tuple) and len(state) == 2:
+                state, slotstate = state
+            if hasattr(instance, '__dict__'):
+                instance.__dict__.update(state)
+            elif state:
+                slotstate.update(state)
+            for key, value in slotstate.items():
+                setattr(object, key, value)
+
+    def construct_python_object(self, suffix, node):
+        # Format:
+        #   !!python/object:module.name { ... state ... }
+        instance = self.make_python_instance(suffix, node, newobj=True)
+        yield instance
+        deep = hasattr(instance, '__setstate__')
+        state = self.construct_mapping(node, deep=deep)
+        self.set_python_instance_state(instance, state)
+
+    def construct_python_object_apply(self, suffix, node, newobj=False):
+        # Format:
+        #   !!python/object/apply       # (or !!python/object/new)
+        #   args: [ ... arguments ... ]
+        #   kwds: { ... keywords ... }
+        #   state: ... state ...
+        #   listitems: [ ... listitems ... ]
+        #   dictitems: { ... dictitems ... }
+        # or short format:
+        #   !!python/object/apply [ ... arguments ... ]
+        # The difference between !!python/object/apply and !!python/object/new
+        # is how an object is created, check make_python_instance for details.
+        if isinstance(node, SequenceNode):
+            args = self.construct_sequence(node, deep=True)
+            kwds = {}
+            state = {}
+            listitems = []
+            dictitems = {}
+        else:
+            value = self.construct_mapping(node, deep=True)
+            args = value.get('args', [])
+            kwds = value.get('kwds', {})
+            state = value.get('state', {})
+            listitems = value.get('listitems', [])
+            dictitems = value.get('dictitems', {})
+        instance = self.make_python_instance(suffix, node, args, kwds, newobj)
+        if state:
+            self.set_python_instance_state(instance, state)
+        if listitems:
+            instance.extend(listitems)
+        if dictitems:
+            for key in dictitems:
+                instance[key] = dictitems[key]
+        return instance
+
+    def construct_python_object_new(self, suffix, node):
+        return self.construct_python_object_apply(suffix, node, newobj=True)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/none',
+    Constructor.construct_yaml_null)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/bool',
+    Constructor.construct_yaml_bool)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/str',
+    Constructor.construct_python_str)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/unicode',
+    Constructor.construct_python_unicode)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/bytes',
+    Constructor.construct_python_bytes)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/int',
+    Constructor.construct_yaml_int)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/long',
+    Constructor.construct_python_long)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/float',
+    Constructor.construct_yaml_float)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/complex',
+    Constructor.construct_python_complex)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/list',
+    Constructor.construct_yaml_seq)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/tuple',
+    Constructor.construct_python_tuple)
+
+Constructor.add_constructor(
+    'tag:yaml.org,2002:python/dict',
+    Constructor.construct_yaml_map)
+
+Constructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/name:',
+    Constructor.construct_python_name)
+
+Constructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/module:',
+    Constructor.construct_python_module)
+
+Constructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/object:',
+    Constructor.construct_python_object)
+
+Constructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/object/apply:',
+    Constructor.construct_python_object_apply)
+
+Constructor.add_multi_constructor(
+    'tag:yaml.org,2002:python/object/new:',
+    Constructor.construct_python_object_new)
+

cement/cli/contrib/yaml/cyaml.py

@@ -0,0 +1,85 @@
+
+__all__ = ['CBaseLoader', 'CSafeLoader', 'CLoader',
+        'CBaseDumper', 'CSafeDumper', 'CDumper']
+
+from _yaml import CParser, CEmitter
+
+from .constructor import *
+
+from .serializer import *
+from .representer import *
+
+from .resolver import *
+
+class CBaseLoader(CParser, BaseConstructor, BaseResolver):
+
+    def __init__(self, stream):
+        CParser.__init__(self, stream)
+        BaseConstructor.__init__(self)
+        BaseResolver.__init__(self)
+
+class CSafeLoader(CParser, SafeConstructor, Resolver):
+
+    def __init__(self, stream):
+        CParser.__init__(self, stream)
+        SafeConstructor.__init__(self)
+        Resolver.__init__(self)
+
+class CLoader(CParser, Constructor, Resolver):
+
+    def __init__(self, stream):
+        CParser.__init__(self, stream)
+        Constructor.__init__(self)
+        Resolver.__init__(self)
+
+class CBaseDumper(CEmitter, BaseRepresenter, BaseResolver):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=None,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None):
+        CEmitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width, encoding=encoding,
+                allow_unicode=allow_unicode, line_break=line_break,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        Representer.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style)
+        Resolver.__init__(self)
+
+class CSafeDumper(CEmitter, SafeRepresenter, Resolver):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=None,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None):
+        CEmitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width, encoding=encoding,
+                allow_unicode=allow_unicode, line_break=line_break,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        SafeRepresenter.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style)
+        Resolver.__init__(self)
+
+class CDumper(CEmitter, Serializer, Representer, Resolver):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=None,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None):
+        CEmitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width, encoding=encoding,
+                allow_unicode=allow_unicode, line_break=line_break,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        Representer.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style)
+        Resolver.__init__(self)
+

cement/cli/contrib/yaml/dumper.py

@@ -0,0 +1,62 @@
+
+__all__ = ['BaseDumper', 'SafeDumper', 'Dumper']
+
+from .emitter import *
+from .serializer import *
+from .representer import *
+from .resolver import *
+
+class BaseDumper(Emitter, Serializer, BaseRepresenter, BaseResolver):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=None,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None):
+        Emitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width,
+                allow_unicode=allow_unicode, line_break=line_break)
+        Serializer.__init__(self, encoding=encoding,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        Representer.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style)
+        Resolver.__init__(self)
+
+class SafeDumper(Emitter, Serializer, SafeRepresenter, Resolver):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=None,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None):
+        Emitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width,
+                allow_unicode=allow_unicode, line_break=line_break)
+        Serializer.__init__(self, encoding=encoding,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        SafeRepresenter.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style)
+        Resolver.__init__(self)
+
+class Dumper(Emitter, Serializer, Representer, Resolver):
+
+    def __init__(self, stream,
+            default_style=None, default_flow_style=None,
+            canonical=None, indent=None, width=None,
+            allow_unicode=None, line_break=None,
+            encoding=None, explicit_start=None, explicit_end=None,
+            version=None, tags=None):
+        Emitter.__init__(self, stream, canonical=canonical,
+                indent=indent, width=width,
+                allow_unicode=allow_unicode, line_break=line_break)
+        Serializer.__init__(self, encoding=encoding,
+                explicit_start=explicit_start, explicit_end=explicit_end,
+                version=version, tags=tags)
+        Representer.__init__(self, default_style=default_style,
+                default_flow_style=default_flow_style)
+        Resolver.__init__(self)
+

cement/cli/contrib/yaml/error.py

@@ -0,0 +1,75 @@
+
+__all__ = ['Mark', 'YAMLError', 'MarkedYAMLError']
+
+class Mark:
+
+    def __init__(self, name, index, line, column, buffer, pointer):
+        self.name = name
+        self.index = index
+        self.line = line
+        self.column = column
+        self.buffer = buffer
+        self.pointer = pointer
+
+    def get_snippet(self, indent=4, max_length=75):
+        if self.buffer is None:
+            return None
+        head = ''
+        start = self.pointer
+        while start > 0 and self.buffer[start-1] not in '\0\r\n\x85\u2028\u2029':
+            start -= 1
+            if self.pointer-start > max_length/2-1:
+                head = ' ... '
+                start += 5
+                break
+        tail = ''
+        end = self.pointer
+        while end < len(self.buffer) and self.buffer[end] not in '\0\r\n\x85\u2028\u2029':
+            end += 1
+            if end-self.pointer > max_length/2-1:
+                tail = ' ... '
+                end -= 5
+                break
+        snippet = self.buffer[start:end]
+        return ' '*indent + head + snippet + tail + '\n'  \
+                + ' '*(indent+self.pointer-start+len(head)) + '^'
+
+    def __str__(self):
+        snippet = self.get_snippet()
+        where = "  in \"%s\", line %d, column %d"   \
+                % (self.name, self.line+1, self.column+1)
+        if snippet is not None:
+            where += ":\n"+snippet
+        return where
+
+class YAMLError(Exception):
+    pass
+
+class MarkedYAMLError(YAMLError):
+
+    def __init__(self, context=None, context_mark=None,
+            problem=None, problem_mark=None, note=None):
+        self.context = context
+        self.context_mark = context_mark
+        self.problem = problem
+        self.problem_mark = problem_mark
+        self.note = note
+
+    def __str__(self):
+        lines = []
+        if self.context is not None:
+            lines.append(self.context)
+        if self.context_mark is not None  \
+            and (self.problem is None or self.problem_mark is None
+                    or self.context_mark.name != self.problem_mark.name
+                    or self.context_mark.line != self.problem_mark.line
+                    or self.context_mark.column != self.problem_mark.column):
+            lines.append(str(self.context_mark))
+        if self.problem is not None:
+            lines.append(self.problem)
+        if self.problem_mark is not None:
+            lines.append(str(self.problem_mark))
+        if self.note is not None:
+            lines.append(self.note)
+        return '\n'.join(lines)
+

cement/cli/contrib/yaml/events.py

@@ -0,0 +1,86 @@
+
+# Abstract classes.
+
+class Event(object):
+    def __init__(self, start_mark=None, end_mark=None):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+    def __repr__(self):
+        attributes = [key for key in ['anchor', 'tag', 'implicit', 'value']
+                if hasattr(self, key)]
+        arguments = ', '.join(['%s=%r' % (key, getattr(self, key))
+                for key in attributes])
+        return '%s(%s)' % (self.__class__.__name__, arguments)
+
+class NodeEvent(Event):
+    def __init__(self, anchor, start_mark=None, end_mark=None):
+        self.anchor = anchor
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+
+class CollectionStartEvent(NodeEvent):
+    def __init__(self, anchor, tag, implicit, start_mark=None, end_mark=None,
+            flow_style=None):
+        self.anchor = anchor
+        self.tag = tag
+        self.implicit = implicit
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.flow_style = flow_style
+
+class CollectionEndEvent(Event):
+    pass
+
+# Implementations.
+
+class StreamStartEvent(Event):
+    def __init__(self, start_mark=None, end_mark=None, encoding=None):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.encoding = encoding
+
+class StreamEndEvent(Event):
+    pass
+
+class DocumentStartEvent(Event):
+    def __init__(self, start_mark=None, end_mark=None,
+            explicit=None, version=None, tags=None):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.explicit = explicit
+        self.version = version
+        self.tags = tags
+
+class DocumentEndEvent(Event):
+    def __init__(self, start_mark=None, end_mark=None,
+            explicit=None):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.explicit = explicit
+
+class AliasEvent(NodeEvent):
+    pass
+
+class ScalarEvent(NodeEvent):
+    def __init__(self, anchor, tag, implicit, value,
+            start_mark=None, end_mark=None, style=None):
+        self.anchor = anchor
+        self.tag = tag
+        self.implicit = implicit
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.style = style
+
+class SequenceStartEvent(CollectionStartEvent):
+    pass
+
+class SequenceEndEvent(CollectionEndEvent):
+    pass
+
+class MappingStartEvent(CollectionStartEvent):
+    pass
+
+class MappingEndEvent(CollectionEndEvent):
+    pass
+

cement/cli/contrib/yaml/loader.py

@@ -0,0 +1,40 @@
+
+__all__ = ['BaseLoader', 'SafeLoader', 'Loader']
+
+from .reader import *
+from .scanner import *
+from .parser import *
+from .composer import *
+from .constructor import *
+from .resolver import *
+
+class BaseLoader(Reader, Scanner, Parser, Composer, BaseConstructor, BaseResolver):
+
+    def __init__(self, stream):
+        Reader.__init__(self, stream)
+        Scanner.__init__(self)
+        Parser.__init__(self)
+        Composer.__init__(self)
+        BaseConstructor.__init__(self)
+        BaseResolver.__init__(self)
+
+class SafeLoader(Reader, Scanner, Parser, Composer, SafeConstructor, Resolver):
+
+    def __init__(self, stream):
+        Reader.__init__(self, stream)
+        Scanner.__init__(self)
+        Parser.__init__(self)
+        Composer.__init__(self)
+        SafeConstructor.__init__(self)
+        Resolver.__init__(self)
+
+class Loader(Reader, Scanner, Parser, Composer, Constructor, Resolver):
+
+    def __init__(self, stream):
+        Reader.__init__(self, stream)
+        Scanner.__init__(self)
+        Parser.__init__(self)
+        Composer.__init__(self)
+        Constructor.__init__(self)
+        Resolver.__init__(self)
+

cement/cli/contrib/yaml/nodes.py

@@ -0,0 +1,49 @@
+
+class Node(object):
+    def __init__(self, tag, value, start_mark, end_mark):
+        self.tag = tag
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+    def __repr__(self):
+        value = self.value
+        #if isinstance(value, list):
+        #    if len(value) == 0:
+        #        value = '<empty>'
+        #    elif len(value) == 1:
+        #        value = '<1 item>'
+        #    else:
+        #        value = '<%d items>' % len(value)
+        #else:
+        #    if len(value) > 75:
+        #        value = repr(value[:70]+u' ... ')
+        #    else:
+        #        value = repr(value)
+        value = repr(value)
+        return '%s(tag=%r, value=%s)' % (self.__class__.__name__, self.tag, value)
+
+class ScalarNode(Node):
+    id = 'scalar'
+    def __init__(self, tag, value,
+            start_mark=None, end_mark=None, style=None):
+        self.tag = tag
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.style = style
+
+class CollectionNode(Node):
+    def __init__(self, tag, value,
+            start_mark=None, end_mark=None, flow_style=None):
+        self.tag = tag
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.flow_style = flow_style
+
+class SequenceNode(CollectionNode):
+    id = 'sequence'
+
+class MappingNode(CollectionNode):
+    id = 'mapping'
+

cement/cli/contrib/yaml/parser.py

@@ -0,0 +1,589 @@
+
+# The following YAML grammar is LL(1) and is parsed by a recursive descent
+# parser.
+#
+# stream            ::= STREAM-START implicit_document? explicit_document* STREAM-END
+# implicit_document ::= block_node DOCUMENT-END*
+# explicit_document ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+# block_node_or_indentless_sequence ::=
+#                       ALIAS
+#                       | properties (block_content | indentless_block_sequence)?
+#                       | block_content
+#                       | indentless_block_sequence
+# block_node        ::= ALIAS
+#                       | properties block_content?
+#                       | block_content
+# flow_node         ::= ALIAS
+#                       | properties flow_content?
+#                       | flow_content
+# properties        ::= TAG ANCHOR? | ANCHOR TAG?
+# block_content     ::= block_collection | flow_collection | SCALAR
+# flow_content      ::= flow_collection | SCALAR
+# block_collection  ::= block_sequence | block_mapping
+# flow_collection   ::= flow_sequence | flow_mapping
+# block_sequence    ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+# indentless_sequence   ::= (BLOCK-ENTRY block_node?)+
+# block_mapping     ::= BLOCK-MAPPING_START
+#                       ((KEY block_node_or_indentless_sequence?)?
+#                       (VALUE block_node_or_indentless_sequence?)?)*
+#                       BLOCK-END
+# flow_sequence     ::= FLOW-SEQUENCE-START
+#                       (flow_sequence_entry FLOW-ENTRY)*
+#                       flow_sequence_entry?
+#                       FLOW-SEQUENCE-END
+# flow_sequence_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+# flow_mapping      ::= FLOW-MAPPING-START
+#                       (flow_mapping_entry FLOW-ENTRY)*
+#                       flow_mapping_entry?
+#                       FLOW-MAPPING-END
+# flow_mapping_entry    ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+#
+# FIRST sets:
+#
+# stream: { STREAM-START }
+# explicit_document: { DIRECTIVE DOCUMENT-START }
+# implicit_document: FIRST(block_node)
+# block_node: { ALIAS TAG ANCHOR SCALAR BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START }
+# flow_node: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START }
+# block_content: { BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START SCALAR }
+# flow_content: { FLOW-SEQUENCE-START FLOW-MAPPING-START SCALAR }
+# block_collection: { BLOCK-SEQUENCE-START BLOCK-MAPPING-START }
+# flow_collection: { FLOW-SEQUENCE-START FLOW-MAPPING-START }
+# block_sequence: { BLOCK-SEQUENCE-START }
+# block_mapping: { BLOCK-MAPPING-START }
+# block_node_or_indentless_sequence: { ALIAS ANCHOR TAG SCALAR BLOCK-SEQUENCE-START BLOCK-MAPPING-START FLOW-SEQUENCE-START FLOW-MAPPING-START BLOCK-ENTRY }
+# indentless_sequence: { ENTRY }
+# flow_collection: { FLOW-SEQUENCE-START FLOW-MAPPING-START }
+# flow_sequence: { FLOW-SEQUENCE-START }
+# flow_mapping: { FLOW-MAPPING-START }
+# flow_sequence_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START KEY }
+# flow_mapping_entry: { ALIAS ANCHOR TAG SCALAR FLOW-SEQUENCE-START FLOW-MAPPING-START KEY }
+
+__all__ = ['Parser', 'ParserError']
+
+from .error import MarkedYAMLError
+from .tokens import *
+from .events import *
+from .scanner import *
+
+class ParserError(MarkedYAMLError):
+    pass
+
+class Parser:
+    # Since writing a recursive-descendant parser is a straightforward task, we
+    # do not give many comments here.
+
+    DEFAULT_TAGS = {
+        '!':   '!',
+        '!!':  'tag:yaml.org,2002:',
+    }
+
+    def __init__(self):
+        self.current_event = None
+        self.yaml_version = None
+        self.tag_handles = {}
+        self.states = []
+        self.marks = []
+        self.state = self.parse_stream_start
+
+    def dispose(self):
+        # Reset the state attributes (to clear self-references)
+        self.states = []
+        self.state = None
+
+    def check_event(self, *choices):
+        # Check the type of the next event.
+        if self.current_event is None:
+            if self.state:
+                self.current_event = self.state()
+        if self.current_event is not None:
+            if not choices:
+                return True
+            for choice in choices:
+                if isinstance(self.current_event, choice):
+                    return True
+        return False
+
+    def peek_event(self):
+        # Get the next event.
+        if self.current_event is None:
+            if self.state:
+                self.current_event = self.state()
+        return self.current_event
+
+    def get_event(self):
+        # Get the next event and proceed further.
+        if self.current_event is None:
+            if self.state:
+                self.current_event = self.state()
+        value = self.current_event
+        self.current_event = None
+        return value
+
+    # stream    ::= STREAM-START implicit_document? explicit_document* STREAM-END
+    # implicit_document ::= block_node DOCUMENT-END*
+    # explicit_document ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+
+    def parse_stream_start(self):
+
+        # Parse the stream start.
+        token = self.get_token()
+        event = StreamStartEvent(token.start_mark, token.end_mark,
+                encoding=token.encoding)
+
+        # Prepare the next state.
+        self.state = self.parse_implicit_document_start
+
+        return event
+
+    def parse_implicit_document_start(self):
+
+        # Parse an implicit document.
+        if not self.check_token(DirectiveToken, DocumentStartToken,
+                StreamEndToken):
+            self.tag_handles = self.DEFAULT_TAGS
+            token = self.peek_token()
+            start_mark = end_mark = token.start_mark
+            event = DocumentStartEvent(start_mark, end_mark,
+                    explicit=False)
+
+            # Prepare the next state.
+            self.states.append(self.parse_document_end)
+            self.state = self.parse_block_node
+
+            return event
+
+        else:
+            return self.parse_document_start()
+
+    def parse_document_start(self):
+
+        # Parse any extra document end indicators.
+        while self.check_token(DocumentEndToken):
+            self.get_token()
+
+        # Parse an explicit document.
+        if not self.check_token(StreamEndToken):
+            token = self.peek_token()
+            start_mark = token.start_mark
+            version, tags = self.process_directives()
+            if not self.check_token(DocumentStartToken):
+                raise ParserError(None, None,
+                        "expected '<document start>', but found %r"
+                        % self.peek_token().id,
+                        self.peek_token().start_mark)
+            token = self.get_token()
+            end_mark = token.end_mark
+            event = DocumentStartEvent(start_mark, end_mark,
+                    explicit=True, version=version, tags=tags)
+            self.states.append(self.parse_document_end)
+            self.state = self.parse_document_content
+        else:
+            # Parse the end of the stream.
+            token = self.get_token()
+            event = StreamEndEvent(token.start_mark, token.end_mark)
+            assert not self.states
+            assert not self.marks
+            self.state = None
+        return event
+
+    def parse_document_end(self):
+
+        # Parse the document end.
+        token = self.peek_token()
+        start_mark = end_mark = token.start_mark
+        explicit = False
+        if self.check_token(DocumentEndToken):
+            token = self.get_token()
+            end_mark = token.end_mark
+            explicit = True
+        event = DocumentEndEvent(start_mark, end_mark,
+                explicit=explicit)
+
+        # Prepare the next state.
+        self.state = self.parse_document_start
+
+        return event
+
+    def parse_document_content(self):
+        if self.check_token(DirectiveToken,
+                DocumentStartToken, DocumentEndToken, StreamEndToken):
+            event = self.process_empty_scalar(self.peek_token().start_mark)
+            self.state = self.states.pop()
+            return event
+        else:
+            return self.parse_block_node()
+
+    def process_directives(self):
+        self.yaml_version = None
+        self.tag_handles = {}
+        while self.check_token(DirectiveToken):
+            token = self.get_token()
+            if token.name == 'YAML':
+                if self.yaml_version is not None:
+                    raise ParserError(None, None,
+                            "found duplicate YAML directive", token.start_mark)
+                major, minor = token.value
+                if major != 1:
+                    raise ParserError(None, None,
+                            "found incompatible YAML document (version 1.* is required)",
+                            token.start_mark)
+                self.yaml_version = token.value
+            elif token.name == 'TAG':
+                handle, prefix = token.value
+                if handle in self.tag_handles:
+                    raise ParserError(None, None,
+                            "duplicate tag handle %r" % handle,
+                            token.start_mark)
+                self.tag_handles[handle] = prefix
+        if self.tag_handles:
+            value = self.yaml_version, self.tag_handles.copy()
+        else:
+            value = self.yaml_version, None
+        for key in self.DEFAULT_TAGS:
+            if key not in self.tag_handles:
+                self.tag_handles[key] = self.DEFAULT_TAGS[key]
+        return value
+
+    # block_node_or_indentless_sequence ::= ALIAS
+    #               | properties (block_content | indentless_block_sequence)?
+    #               | block_content
+    #               | indentless_block_sequence
+    # block_node    ::= ALIAS
+    #                   | properties block_content?
+    #                   | block_content
+    # flow_node     ::= ALIAS
+    #                   | properties flow_content?
+    #                   | flow_content
+    # properties    ::= TAG ANCHOR? | ANCHOR TAG?
+    # block_content     ::= block_collection | flow_collection | SCALAR
+    # flow_content      ::= flow_collection | SCALAR
+    # block_collection  ::= block_sequence | block_mapping
+    # flow_collection   ::= flow_sequence | flow_mapping
+
+    def parse_block_node(self):
+        return self.parse_node(block=True)
+
+    def parse_flow_node(self):
+        return self.parse_node()
+
+    def parse_block_node_or_indentless_sequence(self):
+        return self.parse_node(block=True, indentless_sequence=True)
+
+    def parse_node(self, block=False, indentless_sequence=False):
+        if self.check_token(AliasToken):
+            token = self.get_token()
+            event = AliasEvent(token.value, token.start_mark, token.end_mark)
+            self.state = self.states.pop()
+        else:
+            anchor = None
+            tag = None
+            start_mark = end_mark = tag_mark = None
+            if self.check_token(AnchorToken):
+                token = self.get_token()
+                start_mark = token.start_mark
+                end_mark = token.end_mark
+                anchor = token.value
+                if self.check_token(TagToken):
+                    token = self.get_token()
+                    tag_mark = token.start_mark
+                    end_mark = token.end_mark
+                    tag = token.value
+            elif self.check_token(TagToken):
+                token = self.get_token()
+                start_mark = tag_mark = token.start_mark
+                end_mark = token.end_mark
+                tag = token.value
+                if self.check_token(AnchorToken):
+                    token = self.get_token()
+                    end_mark = token.end_mark
+                    anchor = token.value
+            if tag is not None:
+                handle, suffix = tag
+                if handle is not None:
+                    if handle not in self.tag_handles:
+                        raise ParserError("while parsing a node", start_mark,
+                                "found undefined tag handle %r" % handle,
+                                tag_mark)
+                    tag = self.tag_handles[handle]+suffix
+                else:
+                    tag = suffix
+            #if tag == '!':
+            #    raise ParserError("while parsing a node", start_mark,
+            #            "found non-specific tag '!'", tag_mark,
+            #            "Please check 'http://pyyaml.org/wiki/YAMLNonSpecificTag' and share your opinion.")
+            if start_mark is None:
+                start_mark = end_mark = self.peek_token().start_mark
+            event = None
+            implicit = (tag is None or tag == '!')
+            if indentless_sequence and self.check_token(BlockEntryToken):
+                end_mark = self.peek_token().end_mark
+                event = SequenceStartEvent(anchor, tag, implicit,
+                        start_mark, end_mark)
+                self.state = self.parse_indentless_sequence_entry
+            else:
+                if self.check_token(ScalarToken):
+                    token = self.get_token()
+                    end_mark = token.end_mark
+                    if (token.plain and tag is None) or tag == '!':
+                        implicit = (True, False)
+                    elif tag is None:
+                        implicit = (False, True)
+                    else:
+                        implicit = (False, False)
+                    event = ScalarEvent(anchor, tag, implicit, token.value,
+                            start_mark, end_mark, style=token.style)
+                    self.state = self.states.pop()
+                elif self.check_token(FlowSequenceStartToken):
+                    end_mark = self.peek_token().end_mark
+                    event = SequenceStartEvent(anchor, tag, implicit,
+                            start_mark, end_mark, flow_style=True)
+                    self.state = self.parse_flow_sequence_first_entry
+                elif self.check_token(FlowMappingStartToken):
+                    end_mark = self.peek_token().end_mark
+                    event = MappingStartEvent(anchor, tag, implicit,
+                            start_mark, end_mark, flow_style=True)
+                    self.state = self.parse_flow_mapping_first_key
+                elif block and self.check_token(BlockSequenceStartToken):
+                    end_mark = self.peek_token().start_mark
+                    event = SequenceStartEvent(anchor, tag, implicit,
+                            start_mark, end_mark, flow_style=False)
+                    self.state = self.parse_block_sequence_first_entry
+                elif block and self.check_token(BlockMappingStartToken):
+                    end_mark = self.peek_token().start_mark
+                    event = MappingStartEvent(anchor, tag, implicit,
+                            start_mark, end_mark, flow_style=False)
+                    self.state = self.parse_block_mapping_first_key
+                elif anchor is not None or tag is not None:
+                    # Empty scalars are allowed even if a tag or an anchor is
+                    # specified.
+                    event = ScalarEvent(anchor, tag, (implicit, False), '',
+                            start_mark, end_mark)
+                    self.state = self.states.pop()
+                else:
+                    if block:
+                        node = 'block'
+                    else:
+                        node = 'flow'
+                    token = self.peek_token()
+                    raise ParserError("while parsing a %s node" % node, start_mark,
+                            "expected the node content, but found %r" % token.id,
+                            token.start_mark)
+        return event
+
+    # block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+
+    def parse_block_sequence_first_entry(self):
+        token = self.get_token()
+        self.marks.append(token.start_mark)
+        return self.parse_block_sequence_entry()
+
+    def parse_block_sequence_entry(self):
+        if self.check_token(BlockEntryToken):
+            token = self.get_token()
+            if not self.check_token(BlockEntryToken, BlockEndToken):
+                self.states.append(self.parse_block_sequence_entry)
+                return self.parse_block_node()
+            else:
+                self.state = self.parse_block_sequence_entry
+                return self.process_empty_scalar(token.end_mark)
+        if not self.check_token(BlockEndToken):
+            token = self.peek_token()
+            raise ParserError("while parsing a block collection", self.marks[-1],
+                    "expected <block end>, but found %r" % token.id, token.start_mark)
+        token = self.get_token()
+        event = SequenceEndEvent(token.start_mark, token.end_mark)
+        self.state = self.states.pop()
+        self.marks.pop()
+        return event
+
+    # indentless_sequence ::= (BLOCK-ENTRY block_node?)+
+
+    def parse_indentless_sequence_entry(self):
+        if self.check_token(BlockEntryToken):
+            token = self.get_token()
+            if not self.check_token(BlockEntryToken,
+                    KeyToken, ValueToken, BlockEndToken):
+                self.states.append(self.parse_indentless_sequence_entry)
+                return self.parse_block_node()
+            else:
+                self.state = self.parse_indentless_sequence_entry
+                return self.process_empty_scalar(token.end_mark)
+        token = self.peek_token()
+        event = SequenceEndEvent(token.start_mark, token.start_mark)
+        self.state = self.states.pop()
+        return event
+
+    # block_mapping     ::= BLOCK-MAPPING_START
+    #                       ((KEY block_node_or_indentless_sequence?)?
+    #                       (VALUE block_node_or_indentless_sequence?)?)*
+    #                       BLOCK-END
+
+    def parse_block_mapping_first_key(self):
+        token = self.get_token()
+        self.marks.append(token.start_mark)
+        return self.parse_block_mapping_key()
+
+    def parse_block_mapping_key(self):
+        if self.check_token(KeyToken):
+            token = self.get_token()
+            if not self.check_token(KeyToken, ValueToken, BlockEndToken):
+                self.states.append(self.parse_block_mapping_value)
+                return self.parse_block_node_or_indentless_sequence()
+            else:
+                self.state = self.parse_block_mapping_value
+                return self.process_empty_scalar(token.end_mark)
+        if not self.check_token(BlockEndToken):
+            token = self.peek_token()
+            raise ParserError("while parsing a block mapping", self.marks[-1],
+                    "expected <block end>, but found %r" % token.id, token.start_mark)
+        token = self.get_token()
+        event = MappingEndEvent(token.start_mark, token.end_mark)
+        self.state = self.states.pop()
+        self.marks.pop()
+        return event
+
+    def parse_block_mapping_value(self):
+        if self.check_token(ValueToken):
+            token = self.get_token()
+            if not self.check_token(KeyToken, ValueToken, BlockEndToken):
+                self.states.append(self.parse_block_mapping_key)
+                return self.parse_block_node_or_indentless_sequence()
+            else:
+                self.state = self.parse_block_mapping_key
+                return self.process_empty_scalar(token.end_mark)
+        else:
+            self.state = self.parse_block_mapping_key
+            token = self.peek_token()
+            return self.process_empty_scalar(token.start_mark)
+
+    # flow_sequence     ::= FLOW-SEQUENCE-START
+    #                       (flow_sequence_entry FLOW-ENTRY)*
+    #                       flow_sequence_entry?
+    #                       FLOW-SEQUENCE-END
+    # flow_sequence_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+    #
+    # Note that while production rules for both flow_sequence_entry and
+    # flow_mapping_entry are equal, their interpretations are different.
+    # For `flow_sequence_entry`, the part `KEY flow_node? (VALUE flow_node?)?`
+    # generate an inline mapping (set syntax).
+
+    def parse_flow_sequence_first_entry(self):
+        token = self.get_token()
+        self.marks.append(token.start_mark)
+        return self.parse_flow_sequence_entry(first=True)
+
+    def parse_flow_sequence_entry(self, first=False):
+        if not self.check_token(FlowSequenceEndToken):
+            if not first:
+                if self.check_token(FlowEntryToken):
+                    self.get_token()
+                else:
+                    token = self.peek_token()
+                    raise ParserError("while parsing a flow sequence", self.marks[-1],
+                            "expected ',' or ']', but got %r" % token.id, token.start_mark)
+            
+            if self.check_token(KeyToken):
+                token = self.peek_token()
+                event = MappingStartEvent(None, None, True,
+                        token.start_mark, token.end_mark,
+                        flow_style=True)
+                self.state = self.parse_flow_sequence_entry_mapping_key
+                return event
+            elif not self.check_token(FlowSequenceEndToken):
+                self.states.append(self.parse_flow_sequence_entry)
+                return self.parse_flow_node()
+        token = self.get_token()
+        event = SequenceEndEvent(token.start_mark, token.end_mark)
+        self.state = self.states.pop()
+        self.marks.pop()
+        return event
+
+    def parse_flow_sequence_entry_mapping_key(self):
+        token = self.get_token()
+        if not self.check_token(ValueToken,
+                FlowEntryToken, FlowSequenceEndToken):
+            self.states.append(self.parse_flow_sequence_entry_mapping_value)
+            return self.parse_flow_node()
+        else:
+            self.state = self.parse_flow_sequence_entry_mapping_value
+            return self.process_empty_scalar(token.end_mark)
+
+    def parse_flow_sequence_entry_mapping_value(self):
+        if self.check_token(ValueToken):
+            token = self.get_token()
+            if not self.check_token(FlowEntryToken, FlowSequenceEndToken):
+                self.states.append(self.parse_flow_sequence_entry_mapping_end)
+                return self.parse_flow_node()
+            else:
+                self.state = self.parse_flow_sequence_entry_mapping_end
+                return self.process_empty_scalar(token.end_mark)
+        else:
+            self.state = self.parse_flow_sequence_entry_mapping_end
+            token = self.peek_token()
+            return self.process_empty_scalar(token.start_mark)
+
+    def parse_flow_sequence_entry_mapping_end(self):
+        self.state = self.parse_flow_sequence_entry
+        token = self.peek_token()
+        return MappingEndEvent(token.start_mark, token.start_mark)
+
+    # flow_mapping  ::= FLOW-MAPPING-START
+    #                   (flow_mapping_entry FLOW-ENTRY)*
+    #                   flow_mapping_entry?
+    #                   FLOW-MAPPING-END
+    # flow_mapping_entry    ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+
+    def parse_flow_mapping_first_key(self):
+        token = self.get_token()
+        self.marks.append(token.start_mark)
+        return self.parse_flow_mapping_key(first=True)
+
+    def parse_flow_mapping_key(self, first=False):
+        if not self.check_token(FlowMappingEndToken):
+            if not first:
+                if self.check_token(FlowEntryToken):
+                    self.get_token()
+                else:
+                    token = self.peek_token()
+                    raise ParserError("while parsing a flow mapping", self.marks[-1],
+                            "expected ',' or '}', but got %r" % token.id, token.start_mark)
+            if self.check_token(KeyToken):
+                token = self.get_token()
+                if not self.check_token(ValueToken,
+                        FlowEntryToken, FlowMappingEndToken):
+                    self.states.append(self.parse_flow_mapping_value)
+                    return self.parse_flow_node()
+                else:
+                    self.state = self.parse_flow_mapping_value
+                    return self.process_empty_scalar(token.end_mark)
+            elif not self.check_token(FlowMappingEndToken):
+                self.states.append(self.parse_flow_mapping_empty_value)
+                return self.parse_flow_node()
+        token = self.get_token()
+        event = MappingEndEvent(token.start_mark, token.end_mark)
+        self.state = self.states.pop()
+        self.marks.pop()
+        return event
+
+    def parse_flow_mapping_value(self):
+        if self.check_token(ValueToken):
+            token = self.get_token()
+            if not self.check_token(FlowEntryToken, FlowMappingEndToken):
+                self.states.append(self.parse_flow_mapping_key)
+                return self.parse_flow_node()
+            else:
+                self.state = self.parse_flow_mapping_key
+                return self.process_empty_scalar(token.end_mark)
+        else:
+            self.state = self.parse_flow_mapping_key
+            token = self.peek_token()
+            return self.process_empty_scalar(token.start_mark)
+
+    def parse_flow_mapping_empty_value(self):
+        self.state = self.parse_flow_mapping_key
+        return self.process_empty_scalar(self.peek_token().start_mark)
+
+    def process_empty_scalar(self, mark):
+        return ScalarEvent(None, None, (True, False), '', mark, mark)
+

cement/cli/contrib/yaml/reader.py

@@ -0,0 +1,192 @@
+# This module contains abstractions for the input stream. You don't have to
+# looks further, there are no pretty code.
+#
+# We define two classes here.
+#
+#   Mark(source, line, column)
+# It's just a record and its only use is producing nice error messages.
+# Parser does not use it for any other purposes.
+#
+#   Reader(source, data)
+# Reader determines the encoding of `data` and converts it to unicode.
+# Reader provides the following methods and attributes:
+#   reader.peek(length=1) - return the next `length` characters
+#   reader.forward(length=1) - move the current position to `length` characters.
+#   reader.index - the number of the current character.
+#   reader.line, stream.column - the line and the column of the current character.
+
+__all__ = ['Reader', 'ReaderError']
+
+from .error import YAMLError, Mark
+
+import codecs, re
+
+class ReaderError(YAMLError):
+
+    def __init__(self, name, position, character, encoding, reason):
+        self.name = name
+        self.character = character
+        self.position = position
+        self.encoding = encoding
+        self.reason = reason
+
+    def __str__(self):
+        if isinstance(self.character, bytes):
+            return "'%s' codec can't decode byte #x%02x: %s\n"  \
+                    "  in \"%s\", position %d"    \
+                    % (self.encoding, ord(self.character), self.reason,
+                            self.name, self.position)
+        else:
+            return "unacceptable character #x%04x: %s\n"    \
+                    "  in \"%s\", position %d"    \
+                    % (self.character, self.reason,
+                            self.name, self.position)
+
+class Reader(object):
+    # Reader:
+    # - determines the data encoding and converts it to a unicode string,
+    # - checks if characters are in allowed range,
+    # - adds '\0' to the end.
+
+    # Reader accepts
+    #  - a `bytes` object,
+    #  - a `str` object,
+    #  - a file-like object with its `read` method returning `str`,
+    #  - a file-like object with its `read` method returning `unicode`.
+
+    # Yeah, it's ugly and slow.
+
+    def __init__(self, stream):
+        self.name = None
+        self.stream = None
+        self.stream_pointer = 0
+        self.eof = True
+        self.buffer = ''
+        self.pointer = 0
+        self.raw_buffer = None
+        self.raw_decode = None
+        self.encoding = None
+        self.index = 0
+        self.line = 0
+        self.column = 0
+        if isinstance(stream, str):
+            self.name = "<unicode string>"
+            self.check_printable(stream)
+            self.buffer = stream+'\0'
+        elif isinstance(stream, bytes):
+            self.name = "<byte string>"
+            self.raw_buffer = stream
+            self.determine_encoding()
+        else:
+            self.stream = stream
+            self.name = getattr(stream, 'name', "<file>")
+            self.eof = False
+            self.raw_buffer = None
+            self.determine_encoding()
+
+    def peek(self, index=0):
+        try:
+            return self.buffer[self.pointer+index]
+        except IndexError:
+            self.update(index+1)
+            return self.buffer[self.pointer+index]
+
+    def prefix(self, length=1):
+        if self.pointer+length >= len(self.buffer):
+            self.update(length)
+        return self.buffer[self.pointer:self.pointer+length]
+
+    def forward(self, length=1):
+        if self.pointer+length+1 >= len(self.buffer):
+            self.update(length+1)
+        while length:
+            ch = self.buffer[self.pointer]
+            self.pointer += 1
+            self.index += 1
+            if ch in '\n\x85\u2028\u2029'  \
+                    or (ch == '\r' and self.buffer[self.pointer] != '\n'):
+                self.line += 1
+                self.column = 0
+            elif ch != '\uFEFF':
+                self.column += 1
+            length -= 1
+
+    def get_mark(self):
+        if self.stream is None:
+            return Mark(self.name, self.index, self.line, self.column,
+                    self.buffer, self.pointer)
+        else:
+            return Mark(self.name, self.index, self.line, self.column,
+                    None, None)
+
+    def determine_encoding(self):
+        while not self.eof and (self.raw_buffer is None or len(self.raw_buffer) < 2):
+            self.update_raw()
+        if isinstance(self.raw_buffer, bytes):
+            if self.raw_buffer.startswith(codecs.BOM_UTF16_LE):
+                self.raw_decode = codecs.utf_16_le_decode
+                self.encoding = 'utf-16-le'
+            elif self.raw_buffer.startswith(codecs.BOM_UTF16_BE):
+                self.raw_decode = codecs.utf_16_be_decode
+                self.encoding = 'utf-16-be'
+            else:
+                self.raw_decode = codecs.utf_8_decode
+                self.encoding = 'utf-8'
+        self.update(1)
+
+    NON_PRINTABLE = re.compile('[^\x09\x0A\x0D\x20-\x7E\x85\xA0-\uD7FF\uE000-\uFFFD]')
+    def check_printable(self, data):
+        match = self.NON_PRINTABLE.search(data)
+        if match:
+            character = match.group()
+            position = self.index+(len(self.buffer)-self.pointer)+match.start()
+            raise ReaderError(self.name, position, ord(character),
+                    'unicode', "special characters are not allowed")
+
+    def update(self, length):
+        if self.raw_buffer is None:
+            return
+        self.buffer = self.buffer[self.pointer:]
+        self.pointer = 0
+        while len(self.buffer) < length:
+            if not self.eof:
+                self.update_raw()
+            if self.raw_decode is not None:
+                try:
+                    data, converted = self.raw_decode(self.raw_buffer,
+                            'strict', self.eof)
+                except UnicodeDecodeError as exc:
+                    character = self.raw_buffer[exc.start]
+                    if self.stream is not None:
+                        position = self.stream_pointer-len(self.raw_buffer)+exc.start
+                    else:
+                        position = exc.start
+                    raise ReaderError(self.name, position, character,
+                            exc.encoding, exc.reason)
+            else:
+                data = self.raw_buffer
+                converted = len(data)
+            self.check_printable(data)
+            self.buffer += data
+            self.raw_buffer = self.raw_buffer[converted:]
+            if self.eof:
+                self.buffer += '\0'
+                self.raw_buffer = None
+                break
+
+    def update_raw(self, size=4096):
+        data = self.stream.read(size)
+        if self.raw_buffer is None:
+            self.raw_buffer = data
+        else:
+            self.raw_buffer += data
+        self.stream_pointer += len(data)
+        if not data:
+            self.eof = True
+
+#try:
+#    import psyco
+#    psyco.bind(Reader)
+#except ImportError:
+#    pass
+

cement/cli/contrib/yaml/representer.py

@@ -0,0 +1,387 @@
+
+__all__ = ['BaseRepresenter', 'SafeRepresenter', 'Representer',
+    'RepresenterError']
+
+from .error import *
+from .nodes import *
+
+import datetime, sys, copyreg, types, base64, collections
+
+class RepresenterError(YAMLError):
+    pass
+
+class BaseRepresenter:
+
+    yaml_representers = {}
+    yaml_multi_representers = {}
+
+    def __init__(self, default_style=None, default_flow_style=None):
+        self.default_style = default_style
+        self.default_flow_style = default_flow_style
+        self.represented_objects = {}
+        self.object_keeper = []
+        self.alias_key = None
+
+    def represent(self, data):
+        node = self.represent_data(data)
+        self.serialize(node)
+        self.represented_objects = {}
+        self.object_keeper = []
+        self.alias_key = None
+
+    def represent_data(self, data):
+        if self.ignore_aliases(data):
+            self.alias_key = None
+        else:
+            self.alias_key = id(data)
+        if self.alias_key is not None:
+            if self.alias_key in self.represented_objects:
+                node = self.represented_objects[self.alias_key]
+                #if node is None:
+                #    raise RepresenterError("recursive objects are not allowed: %r" % data)
+                return node
+            #self.represented_objects[alias_key] = None
+            self.object_keeper.append(data)
+        data_types = type(data).__mro__
+        if data_types[0] in self.yaml_representers:
+            node = self.yaml_representers[data_types[0]](self, data)
+        else:
+            for data_type in data_types:
+                if data_type in self.yaml_multi_representers:
+                    node = self.yaml_multi_representers[data_type](self, data)
+                    break
+            else:
+                if None in self.yaml_multi_representers:
+                    node = self.yaml_multi_representers[None](self, data)
+                elif None in self.yaml_representers:
+                    node = self.yaml_representers[None](self, data)
+                else:
+                    node = ScalarNode(None, str(data))
+        #if alias_key is not None:
+        #    self.represented_objects[alias_key] = node
+        return node
+
+    @classmethod
+    def add_representer(cls, data_type, representer):
+        if not 'yaml_representers' in cls.__dict__:
+            cls.yaml_representers = cls.yaml_representers.copy()
+        cls.yaml_representers[data_type] = representer
+
+    @classmethod
+    def add_multi_representer(cls, data_type, representer):
+        if not 'yaml_multi_representers' in cls.__dict__:
+            cls.yaml_multi_representers = cls.yaml_multi_representers.copy()
+        cls.yaml_multi_representers[data_type] = representer
+
+    def represent_scalar(self, tag, value, style=None):
+        if style is None:
+            style = self.default_style
+        node = ScalarNode(tag, value, style=style)
+        if self.alias_key is not None:
+            self.represented_objects[self.alias_key] = node
+        return node
+
+    def represent_sequence(self, tag, sequence, flow_style=None):
+        value = []
+        node = SequenceNode(tag, value, flow_style=flow_style)
+        if self.alias_key is not None:
+            self.represented_objects[self.alias_key] = node
+        best_style = True
+        for item in sequence:
+            node_item = self.represent_data(item)
+            if not (isinstance(node_item, ScalarNode) and not node_item.style):
+                best_style = False
+            value.append(node_item)
+        if flow_style is None:
+            if self.default_flow_style is not None:
+                node.flow_style = self.default_flow_style
+            else:
+                node.flow_style = best_style
+        return node
+
+    def represent_mapping(self, tag, mapping, flow_style=None):
+        value = []
+        node = MappingNode(tag, value, flow_style=flow_style)
+        if self.alias_key is not None:
+            self.represented_objects[self.alias_key] = node
+        best_style = True
+        if hasattr(mapping, 'items'):
+            mapping = list(mapping.items())
+            try:
+                mapping = sorted(mapping)
+            except TypeError:
+                pass
+        for item_key, item_value in mapping:
+            node_key = self.represent_data(item_key)
+            node_value = self.represent_data(item_value)
+            if not (isinstance(node_key, ScalarNode) and not node_key.style):
+                best_style = False
+            if not (isinstance(node_value, ScalarNode) and not node_value.style):
+                best_style = False
+            value.append((node_key, node_value))
+        if flow_style is None:
+            if self.default_flow_style is not None:
+                node.flow_style = self.default_flow_style
+            else:
+                node.flow_style = best_style
+        return node
+
+    def ignore_aliases(self, data):
+        return False
+
+class SafeRepresenter(BaseRepresenter):
+
+    def ignore_aliases(self, data):
+        if data is None:
+            return True
+        if isinstance(data, tuple) and data == ():
+            return True
+        if isinstance(data, (str, bytes, bool, int, float)):
+            return True
+
+    def represent_none(self, data):
+        return self.represent_scalar('tag:yaml.org,2002:null', 'null')
+
+    def represent_str(self, data):
+        return self.represent_scalar('tag:yaml.org,2002:str', data)
+
+    def represent_binary(self, data):
+        if hasattr(base64, 'encodebytes'):
+            data = base64.encodebytes(data).decode('ascii')
+        else:
+            data = base64.encodestring(data).decode('ascii')
+        return self.represent_scalar('tag:yaml.org,2002:binary', data, style='|')
+
+    def represent_bool(self, data):
+        if data:
+            value = 'true'
+        else:
+            value = 'false'
+        return self.represent_scalar('tag:yaml.org,2002:bool', value)
+
+    def represent_int(self, data):
+        return self.represent_scalar('tag:yaml.org,2002:int', str(data))
+
+    inf_value = 1e300
+    while repr(inf_value) != repr(inf_value*inf_value):
+        inf_value *= inf_value
+
+    def represent_float(self, data):
+        if data != data or (data == 0.0 and data == 1.0):
+            value = '.nan'
+        elif data == self.inf_value:
+            value = '.inf'
+        elif data == -self.inf_value:
+            value = '-.inf'
+        else:
+            value = repr(data).lower()
+            # Note that in some cases `repr(data)` represents a float number
+            # without the decimal parts.  For instance:
+            #   >>> repr(1e17)
+            #   '1e17'
+            # Unfortunately, this is not a valid float representation according
+            # to the definition of the `!!float` tag.  We fix this by adding
+            # '.0' before the 'e' symbol.
+            if '.' not in value and 'e' in value:
+                value = value.replace('e', '.0e', 1)
+        return self.represent_scalar('tag:yaml.org,2002:float', value)
+
+    def represent_list(self, data):
+        #pairs = (len(data) > 0 and isinstance(data, list))
+        #if pairs:
+        #    for item in data:
+        #        if not isinstance(item, tuple) or len(item) != 2:
+        #            pairs = False
+        #            break
+        #if not pairs:
+            return self.represent_sequence('tag:yaml.org,2002:seq', data)
+        #value = []
+        #for item_key, item_value in data:
+        #    value.append(self.represent_mapping(u'tag:yaml.org,2002:map',
+        #        [(item_key, item_value)]))
+        #return SequenceNode(u'tag:yaml.org,2002:pairs', value)
+
+    def represent_dict(self, data):
+        return self.represent_mapping('tag:yaml.org,2002:map', data)
+
+    def represent_set(self, data):
+        value = {}
+        for key in data:
+            value[key] = None
+        return self.represent_mapping('tag:yaml.org,2002:set', value)
+
+    def represent_date(self, data):
+        value = data.isoformat()
+        return self.represent_scalar('tag:yaml.org,2002:timestamp', value)
+
+    def represent_datetime(self, data):
+        value = data.isoformat(' ')
+        return self.represent_scalar('tag:yaml.org,2002:timestamp', value)
+
+    def represent_yaml_object(self, tag, data, cls, flow_style=None):
+        if hasattr(data, '__getstate__'):
+            state = data.__getstate__()
+        else:
+            state = data.__dict__.copy()
+        return self.represent_mapping(tag, state, flow_style=flow_style)
+
+    def represent_undefined(self, data):
+        raise RepresenterError("cannot represent an object: %s" % data)
+
+SafeRepresenter.add_representer(type(None),
+        SafeRepresenter.represent_none)
+
+SafeRepresenter.add_representer(str,
+        SafeRepresenter.represent_str)
+
+SafeRepresenter.add_representer(bytes,
+        SafeRepresenter.represent_binary)
+
+SafeRepresenter.add_representer(bool,
+        SafeRepresenter.represent_bool)
+
+SafeRepresenter.add_representer(int,
+        SafeRepresenter.represent_int)
+
+SafeRepresenter.add_representer(float,
+        SafeRepresenter.represent_float)
+
+SafeRepresenter.add_representer(list,
+        SafeRepresenter.represent_list)
+
+SafeRepresenter.add_representer(tuple,
+        SafeRepresenter.represent_list)
+
+SafeRepresenter.add_representer(dict,
+        SafeRepresenter.represent_dict)
+
+SafeRepresenter.add_representer(set,
+        SafeRepresenter.represent_set)
+
+SafeRepresenter.add_representer(datetime.date,
+        SafeRepresenter.represent_date)
+
+SafeRepresenter.add_representer(datetime.datetime,
+        SafeRepresenter.represent_datetime)
+
+SafeRepresenter.add_representer(None,
+        SafeRepresenter.represent_undefined)
+
+class Representer(SafeRepresenter):
+
+    def represent_complex(self, data):
+        if data.imag == 0.0:
+            data = '%r' % data.real
+        elif data.real == 0.0:
+            data = '%rj' % data.imag
+        elif data.imag > 0:
+            data = '%r+%rj' % (data.real, data.imag)
+        else:
+            data = '%r%rj' % (data.real, data.imag)
+        return self.represent_scalar('tag:yaml.org,2002:python/complex', data)
+
+    def represent_tuple(self, data):
+        return self.represent_sequence('tag:yaml.org,2002:python/tuple', data)
+
+    def represent_name(self, data):
+        name = '%s.%s' % (data.__module__, data.__name__)
+        return self.represent_scalar('tag:yaml.org,2002:python/name:'+name, '')
+
+    def represent_module(self, data):
+        return self.represent_scalar(
+                'tag:yaml.org,2002:python/module:'+data.__name__, '')
+
+    def represent_object(self, data):
+        # We use __reduce__ API to save the data. data.__reduce__ returns
+        # a tuple of length 2-5:
+        #   (function, args, state, listitems, dictitems)
+
+        # For reconstructing, we calls function(*args), then set its state,
+        # listitems, and dictitems if they are not None.
+
+        # A special case is when function.__name__ == '__newobj__'. In this
+        # case we create the object with args[0].__new__(*args).
+
+        # Another special case is when __reduce__ returns a string - we don't
+        # support it.
+
+        # We produce a !!python/object, !!python/object/new or
+        # !!python/object/apply node.
+
+        cls = type(data)
+        if cls in copyreg.dispatch_table:
+            reduce = copyreg.dispatch_table[cls](data)
+        elif hasattr(data, '__reduce_ex__'):
+            reduce = data.__reduce_ex__(2)
+        elif hasattr(data, '__reduce__'):
+            reduce = data.__reduce__()
+        else:
+            raise RepresenterError("cannot represent object: %r" % data)
+        reduce = (list(reduce)+[None]*5)[:5]
+        function, args, state, listitems, dictitems = reduce
+        args = list(args)
+        if state is None:
+            state = {}
+        if listitems is not None:
+            listitems = list(listitems)
+        if dictitems is not None:
+            dictitems = dict(dictitems)
+        if function.__name__ == '__newobj__':
+            function = args[0]
+            args = args[1:]
+            tag = 'tag:yaml.org,2002:python/object/new:'
+            newobj = True
+        else:
+            tag = 'tag:yaml.org,2002:python/object/apply:'
+            newobj = False
+        function_name = '%s.%s' % (function.__module__, function.__name__)
+        if not args and not listitems and not dictitems \
+                and isinstance(state, dict) and newobj:
+            return self.represent_mapping(
+                    'tag:yaml.org,2002:python/object:'+function_name, state)
+        if not listitems and not dictitems  \
+                and isinstance(state, dict) and not state:
+            return self.represent_sequence(tag+function_name, args)
+        value = {}
+        if args:
+            value['args'] = args
+        if state or not isinstance(state, dict):
+            value['state'] = state
+        if listitems:
+            value['listitems'] = listitems
+        if dictitems:
+            value['dictitems'] = dictitems
+        return self.represent_mapping(tag+function_name, value)
+
+    def represent_ordered_dict(self, data):
+        # Provide uniform representation across different Python versions.
+        data_type = type(data)
+        tag = 'tag:yaml.org,2002:python/object/apply:%s.%s' \
+                % (data_type.__module__, data_type.__name__)
+        items = [[key, value] for key, value in data.items()]
+        return self.represent_sequence(tag, [items])
+
+Representer.add_representer(complex,
+        Representer.represent_complex)
+
+Representer.add_representer(tuple,
+        Representer.represent_tuple)
+
+Representer.add_representer(type,
+        Representer.represent_name)
+
+Representer.add_representer(collections.OrderedDict,
+        Representer.represent_ordered_dict)
+
+Representer.add_representer(types.FunctionType,
+        Representer.represent_name)
+
+Representer.add_representer(types.BuiltinFunctionType,
+        Representer.represent_name)
+
+Representer.add_representer(types.ModuleType,
+        Representer.represent_module)
+
+Representer.add_multi_representer(object,
+        Representer.represent_object)
+

cement/cli/contrib/yaml/resolver.py

@@ -0,0 +1,227 @@
+
+__all__ = ['BaseResolver', 'Resolver']
+
+from .error import *
+from .nodes import *
+
+import re
+
+class ResolverError(YAMLError):
+    pass
+
+class BaseResolver:
+
+    DEFAULT_SCALAR_TAG = 'tag:yaml.org,2002:str'
+    DEFAULT_SEQUENCE_TAG = 'tag:yaml.org,2002:seq'
+    DEFAULT_MAPPING_TAG = 'tag:yaml.org,2002:map'
+
+    yaml_implicit_resolvers = {}
+    yaml_path_resolvers = {}
+
+    def __init__(self):
+        self.resolver_exact_paths = []
+        self.resolver_prefix_paths = []
+
+    @classmethod
+    def add_implicit_resolver(cls, tag, regexp, first):
+        if not 'yaml_implicit_resolvers' in cls.__dict__:
+            implicit_resolvers = {}
+            for key in cls.yaml_implicit_resolvers:
+                implicit_resolvers[key] = cls.yaml_implicit_resolvers[key][:]
+            cls.yaml_implicit_resolvers = implicit_resolvers
+        if first is None:
+            first = [None]
+        for ch in first:
+            cls.yaml_implicit_resolvers.setdefault(ch, []).append((tag, regexp))
+
+    @classmethod
+    def add_path_resolver(cls, tag, path, kind=None):
+        # Note: `add_path_resolver` is experimental.  The API could be changed.
+        # `new_path` is a pattern that is matched against the path from the
+        # root to the node that is being considered.  `node_path` elements are
+        # tuples `(node_check, index_check)`.  `node_check` is a node class:
+        # `ScalarNode`, `SequenceNode`, `MappingNode` or `None`.  `None`
+        # matches any kind of a node.  `index_check` could be `None`, a boolean
+        # value, a string value, or a number.  `None` and `False` match against
+        # any _value_ of sequence and mapping nodes.  `True` matches against
+        # any _key_ of a mapping node.  A string `index_check` matches against
+        # a mapping value that corresponds to a scalar key which content is
+        # equal to the `index_check` value.  An integer `index_check` matches
+        # against a sequence value with the index equal to `index_check`.
+        if not 'yaml_path_resolvers' in cls.__dict__:
+            cls.yaml_path_resolvers = cls.yaml_path_resolvers.copy()
+        new_path = []
+        for element in path:
+            if isinstance(element, (list, tuple)):
+                if len(element) == 2:
+                    node_check, index_check = element
+                elif len(element) == 1:
+                    node_check = element[0]
+                    index_check = True
+                else:
+                    raise ResolverError("Invalid path element: %s" % element)
+            else:
+                node_check = None
+                index_check = element
+            if node_check is str:
+                node_check = ScalarNode
+            elif node_check is list:
+                node_check = SequenceNode
+            elif node_check is dict:
+                node_check = MappingNode
+            elif node_check not in [ScalarNode, SequenceNode, MappingNode]  \
+                    and not isinstance(node_check, str) \
+                    and node_check is not None:
+                raise ResolverError("Invalid node checker: %s" % node_check)
+            if not isinstance(index_check, (str, int))  \
+                    and index_check is not None:
+                raise ResolverError("Invalid index checker: %s" % index_check)
+            new_path.append((node_check, index_check))
+        if kind is str:
+            kind = ScalarNode
+        elif kind is list:
+            kind = SequenceNode
+        elif kind is dict:
+            kind = MappingNode
+        elif kind not in [ScalarNode, SequenceNode, MappingNode]    \
+                and kind is not None:
+            raise ResolverError("Invalid node kind: %s" % kind)
+        cls.yaml_path_resolvers[tuple(new_path), kind] = tag
+
+    def descend_resolver(self, current_node, current_index):
+        if not self.yaml_path_resolvers:
+            return
+        exact_paths = {}
+        prefix_paths = []
+        if current_node:
+            depth = len(self.resolver_prefix_paths)
+            for path, kind in self.resolver_prefix_paths[-1]:
+                if self.check_resolver_prefix(depth, path, kind,
+                        current_node, current_index):
+                    if len(path) > depth:
+                        prefix_paths.append((path, kind))
+                    else:
+                        exact_paths[kind] = self.yaml_path_resolvers[path, kind]
+        else:
+            for path, kind in self.yaml_path_resolvers:
+                if not path:
+                    exact_paths[kind] = self.yaml_path_resolvers[path, kind]
+                else:
+                    prefix_paths.append((path, kind))
+        self.resolver_exact_paths.append(exact_paths)
+        self.resolver_prefix_paths.append(prefix_paths)
+
+    def ascend_resolver(self):
+        if not self.yaml_path_resolvers:
+            return
+        self.resolver_exact_paths.pop()
+        self.resolver_prefix_paths.pop()
+
+    def check_resolver_prefix(self, depth, path, kind,
+            current_node, current_index):
+        node_check, index_check = path[depth-1]
+        if isinstance(node_check, str):
+            if current_node.tag != node_check:
+                return
+        elif node_check is not None:
+            if not isinstance(current_node, node_check):
+                return
+        if index_check is True and current_index is not None:
+            return
+        if (index_check is False or index_check is None)    \
+                and current_index is None:
+            return
+        if isinstance(index_check, str):
+            if not (isinstance(current_index, ScalarNode)
+                    and index_check == current_index.value):
+                return
+        elif isinstance(index_check, int) and not isinstance(index_check, bool):
+            if index_check != current_index:
+                return
+        return True
+
+    def resolve(self, kind, value, implicit):
+        if kind is ScalarNode and implicit[0]:
+            if value == '':
+                resolvers = self.yaml_implicit_resolvers.get('', [])
+            else:
+                resolvers = self.yaml_implicit_resolvers.get(value[0], [])
+            resolvers += self.yaml_implicit_resolvers.get(None, [])
+            for tag, regexp in resolvers:
+                if regexp.match(value):
+                    return tag
+            implicit = implicit[1]
+        if self.yaml_path_resolvers:
+            exact_paths = self.resolver_exact_paths[-1]
+            if kind in exact_paths:
+                return exact_paths[kind]
+            if None in exact_paths:
+                return exact_paths[None]
+        if kind is ScalarNode:
+            return self.DEFAULT_SCALAR_TAG
+        elif kind is SequenceNode:
+            return self.DEFAULT_SEQUENCE_TAG
+        elif kind is MappingNode:
+            return self.DEFAULT_MAPPING_TAG
+
+class Resolver(BaseResolver):
+    pass
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:bool',
+        re.compile(r'''^(?:yes|Yes|YES|no|No|NO
+                    |true|True|TRUE|false|False|FALSE
+                    |on|On|ON|off|Off|OFF)$''', re.X),
+        list('yYnNtTfFoO'))
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:float',
+        re.compile(r'''^(?:[-+]?(?:[0-9][0-9_]*)\.[0-9_]*(?:[eE][-+][0-9]+)?
+                    |\.[0-9_]+(?:[eE][-+][0-9]+)?
+                    |[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\.[0-9_]*
+                    |[-+]?\.(?:inf|Inf|INF)
+                    |\.(?:nan|NaN|NAN))$''', re.X),
+        list('-+0123456789.'))
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:int',
+        re.compile(r'''^(?:[-+]?0b[0-1_]+
+                    |[-+]?0[0-7_]+
+                    |[-+]?(?:0|[1-9][0-9_]*)
+                    |[-+]?0x[0-9a-fA-F_]+
+                    |[-+]?[1-9][0-9_]*(?::[0-5]?[0-9])+)$''', re.X),
+        list('-+0123456789'))
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:merge',
+        re.compile(r'^(?:<<)$'),
+        ['<'])
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:null',
+        re.compile(r'''^(?: ~
+                    |null|Null|NULL
+                    | )$''', re.X),
+        ['~', 'n', 'N', ''])
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:timestamp',
+        re.compile(r'''^(?:[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]
+                    |[0-9][0-9][0-9][0-9] -[0-9][0-9]? -[0-9][0-9]?
+                     (?:[Tt]|[ \t]+)[0-9][0-9]?
+                     :[0-9][0-9] :[0-9][0-9] (?:\.[0-9]*)?
+                     (?:[ \t]*(?:Z|[-+][0-9][0-9]?(?::[0-9][0-9])?))?)$''', re.X),
+        list('0123456789'))
+
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:value',
+        re.compile(r'^(?:=)$'),
+        ['='])
+
+# The following resolver is only for documentation purposes. It cannot work
+# because plain scalars cannot start with '!', '&', or '*'.
+Resolver.add_implicit_resolver(
+        'tag:yaml.org,2002:yaml',
+        re.compile(r'^(?:!|&|\*)$'),
+        list('!&*'))
+

cement/cli/contrib/yaml/serializer.py

@@ -0,0 +1,111 @@
+
+__all__ = ['Serializer', 'SerializerError']
+
+from .error import YAMLError
+from .events import *
+from .nodes import *
+
+class SerializerError(YAMLError):
+    pass
+
+class Serializer:
+
+    ANCHOR_TEMPLATE = 'id%03d'
+
+    def __init__(self, encoding=None,
+            explicit_start=None, explicit_end=None, version=None, tags=None):
+        self.use_encoding = encoding
+        self.use_explicit_start = explicit_start
+        self.use_explicit_end = explicit_end
+        self.use_version = version
+        self.use_tags = tags
+        self.serialized_nodes = {}
+        self.anchors = {}
+        self.last_anchor_id = 0
+        self.closed = None
+
+    def open(self):
+        if self.closed is None:
+            self.emit(StreamStartEvent(encoding=self.use_encoding))
+            self.closed = False
+        elif self.closed:
+            raise SerializerError("serializer is closed")
+        else:
+            raise SerializerError("serializer is already opened")
+
+    def close(self):
+        if self.closed is None:
+            raise SerializerError("serializer is not opened")
+        elif not self.closed:
+            self.emit(StreamEndEvent())
+            self.closed = True
+
+    #def __del__(self):
+    #    self.close()
+
+    def serialize(self, node):
+        if self.closed is None:
+            raise SerializerError("serializer is not opened")
+        elif self.closed:
+            raise SerializerError("serializer is closed")
+        self.emit(DocumentStartEvent(explicit=self.use_explicit_start,
+            version=self.use_version, tags=self.use_tags))
+        self.anchor_node(node)
+        self.serialize_node(node, None, None)
+        self.emit(DocumentEndEvent(explicit=self.use_explicit_end))
+        self.serialized_nodes = {}
+        self.anchors = {}
+        self.last_anchor_id = 0
+
+    def anchor_node(self, node):
+        if node in self.anchors:
+            if self.anchors[node] is None:
+                self.anchors[node] = self.generate_anchor(node)
+        else:
+            self.anchors[node] = None
+            if isinstance(node, SequenceNode):
+                for item in node.value:
+                    self.anchor_node(item)
+            elif isinstance(node, MappingNode):
+                for key, value in node.value:
+                    self.anchor_node(key)
+                    self.anchor_node(value)
+
+    def generate_anchor(self, node):
+        self.last_anchor_id += 1
+        return self.ANCHOR_TEMPLATE % self.last_anchor_id
+
+    def serialize_node(self, node, parent, index):
+        alias = self.anchors[node]
+        if node in self.serialized_nodes:
+            self.emit(AliasEvent(alias))
+        else:
+            self.serialized_nodes[node] = True
+            self.descend_resolver(parent, index)
+            if isinstance(node, ScalarNode):
+                detected_tag = self.resolve(ScalarNode, node.value, (True, False))
+                default_tag = self.resolve(ScalarNode, node.value, (False, True))
+                implicit = (node.tag == detected_tag), (node.tag == default_tag)
+                self.emit(ScalarEvent(alias, node.tag, implicit, node.value,
+                    style=node.style))
+            elif isinstance(node, SequenceNode):
+                implicit = (node.tag
+                            == self.resolve(SequenceNode, node.value, True))
+                self.emit(SequenceStartEvent(alias, node.tag, implicit,
+                    flow_style=node.flow_style))
+                index = 0
+                for item in node.value:
+                    self.serialize_node(item, node, index)
+                    index += 1
+                self.emit(SequenceEndEvent())
+            elif isinstance(node, MappingNode):
+                implicit = (node.tag
+                            == self.resolve(MappingNode, node.value, True))
+                self.emit(MappingStartEvent(alias, node.tag, implicit,
+                    flow_style=node.flow_style))
+                for key, value in node.value:
+                    self.serialize_node(key, node, None)
+                    self.serialize_node(value, node, key)
+                self.emit(MappingEndEvent())
+            self.ascend_resolver()
+

cement/cli/contrib/yaml/tokens.py

@@ -0,0 +1,104 @@
+
+class Token(object):
+    def __init__(self, start_mark, end_mark):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+    def __repr__(self):
+        attributes = [key for key in self.__dict__
+                if not key.endswith('_mark')]
+        attributes.sort()
+        arguments = ', '.join(['%s=%r' % (key, getattr(self, key))
+                for key in attributes])
+        return '%s(%s)' % (self.__class__.__name__, arguments)
+
+#class BOMToken(Token):
+#    id = '<byte order mark>'
+
+class DirectiveToken(Token):
+    id = '<directive>'
+    def __init__(self, name, value, start_mark, end_mark):
+        self.name = name
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+
+class DocumentStartToken(Token):
+    id = '<document start>'
+
+class DocumentEndToken(Token):
+    id = '<document end>'
+
+class StreamStartToken(Token):
+    id = '<stream start>'
+    def __init__(self, start_mark=None, end_mark=None,
+            encoding=None):
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.encoding = encoding
+
+class StreamEndToken(Token):
+    id = '<stream end>'
+
+class BlockSequenceStartToken(Token):
+    id = '<block sequence start>'
+
+class BlockMappingStartToken(Token):
+    id = '<block mapping start>'
+
+class BlockEndToken(Token):
+    id = '<block end>'
+
+class FlowSequenceStartToken(Token):
+    id = '['
+
+class FlowMappingStartToken(Token):
+    id = '{'
+
+class FlowSequenceEndToken(Token):
+    id = ']'
+
+class FlowMappingEndToken(Token):
+    id = '}'
+
+class KeyToken(Token):
+    id = '?'
+
+class ValueToken(Token):
+    id = ':'
+
+class BlockEntryToken(Token):
+    id = '-'
+
+class FlowEntryToken(Token):
+    id = ','
+
+class AliasToken(Token):
+    id = '<alias>'
+    def __init__(self, value, start_mark, end_mark):
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+
+class AnchorToken(Token):
+    id = '<anchor>'
+    def __init__(self, value, start_mark, end_mark):
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+
+class TagToken(Token):
+    id = '<tag>'
+    def __init__(self, value, start_mark, end_mark):
+        self.value = value
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+
+class ScalarToken(Token):
+    id = '<scalar>'
+    def __init__(self, value, plain, start_mark, end_mark, style=None):
+        self.value = value
+        self.plain = plain
+        self.start_mark = start_mark
+        self.end_mark = end_mark
+        self.style = style
+

cement/cli/controllers/base.py

@@ -0,0 +1,12 @@
+
+from cement import Controller
+
+
+class Base(Controller):
+    class Meta:
+        label = 'base'
+        description = 'Cement Framework Developer Tools'
+        epilog = 'Example: cement generate app /path/to/myapp'
+
+    def _default(self):
+        self.app.args.print_help()

cement/cli/main.py

@@ -0,0 +1,53 @@
+
+import os
+import sys
+sys.path.append(os.path.join(os.path.dirname(__file__), 'contrib'))
+
+from cement import App, init_defaults, CaughtSignal         # noqa: E402
+from .controllers.base import Base                          # noqa: E402
+
+META = init_defaults('generate')
+
+
+class CementApp(App):
+    class Meta:
+        label = 'cement'
+        controller = 'base'
+        meta_defaults = META
+        template_module = 'cement.cli.templates'
+        template_handler = 'jinja2'
+        config_handler = 'yaml'
+        config_file_suffix = '.yml'
+
+        extensions = [
+            'generate',
+            'yaml',
+            'jinja2',
+        ]
+
+        handlers = [
+            Base,
+        ]
+
+
+class CementTestApp(CementApp):
+    class Meta:
+        argv = []
+        config_files = []
+        exit_on_close = False
+
+
+def main(argv=None):
+    with CementApp() as app:
+        try:
+            app.run()
+        except AssertionError as e:                     # pragma: nocover
+            print('AssertionError > %s' % e.args[0])    # pragma: nocover
+            app.exit_code = 1                           # pragma: nocover
+        except CaughtSignal as e:                       # pragma: nocover
+            print('\n%s' % e)                           # pragma: nocover
+            app.exit_code = 0                           # pragma: nocover
+
+
+if __name__ == '__main__':
+    main()                                              # pragma: nocover

cement/cli/templates/generate/app/.generate.yml

@@ -0,0 +1,39 @@
+---
+
+exclude:
+    - '^(.*)[\/\\\\]app[\/\\\\]{{ label }}[\/\\\\]templates[\/\\\\](.*)$'
+
+variables:
+    -   name: label
+        prompt: "App Label"
+        case: "lower"
+        default: "myapp"
+
+    -   name: name
+        prompt: "App Name"
+        default: "My Application"
+
+    -   name: class_name
+        prompt: "App Class Name"
+        validate: "^[a-zA-Z0-9]+$"
+        default: "MyApp"
+
+    -   name: description
+        prompt: "App Description"
+        default: "MyApp Does Amazing Things!"
+
+    -   name: creator
+        prompt: "Creator Name"
+        default: "John Doe"
+
+    -   name: creator_email
+        prompt: "Creator Email"
+        default: "john.doe@example.com"
+
+    -   name: url
+        prompt: "Project URL"
+        default: "https://github.com/johndoe/myapp/"
+
+    -   name: license
+        prompt: "License"
+        default: "unlicensed"

cement/cli/templates/generate/app/.gitignore

@@ -0,0 +1,105 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+coverage-report/
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/

cement/cli/templates/generate/app/Dockerfile

@@ -0,0 +1,15 @@
+FROM python:3.6-alpine
+MAINTAINER {{ creator }} <{{ creator_email }}>
+WORKDIR /app
+COPY . /app
+RUN apk update \
+    && apk add git \
+    && pip install --no-cache-dir -r requirements.txt \
+    && rm -f /usr/local/lib/python3.6/site-packages/cement.egg-link \
+    && cd src/cement \
+    && python setup.py install \
+    && cd /app \
+    && python setup.py install \
+    && rm -rf /app
+WORKDIR /
+ENTRYPOINT ["{{ label }}"]

cement/cli/templates/generate/app/LICENSE.md

@@ -0,0 +1 @@
+

cement/cli/templates/generate/app/MANIFEST.in

@@ -0,0 +1,4 @@
+recursive-include *.py
+include setup.cfg
+include README.md CHANGELOG.md LICENSE.md
+include *.txt

cement/cli/templates/generate/app/Makefile

@@ -0,0 +1,28 @@
+.PHONY: clean dev test docker dist dist-upload
+
+clean:
+	find . -name '*.py[co]' -delete
+	rm -rf docs/build
+
+dev:
+	docker-compose up -d
+	docker-compose exec {{ label }} /bin/ash
+
+test:
+	python -m pytest \
+		-v \
+		--cov={{ label }} \
+		--cov-report=term \
+		--cov-report=html:coverage-report \
+		tests/
+
+docker: clean
+	docker build -t {{ label }}:latest .
+
+dist: clean
+	rm -rf dist/*
+	python setup.py sdist
+	python setup.py bdist_wheel
+
+dist-upload:
+	twine upload dist/*

cement/cli/templates/generate/app/README.md

@@ -0,0 +1,85 @@
+# {{ description }}
+
+## Installation
+
+```
+$ pip install -r requirements.txt
+
+$ pip install setup.py
+```
+
+## Development
+
+### Environment Setup
+
+This project includes a basic Docker Compose configuration that will setup a local development environment with all dependencies, and services required for development and testing.
+
+```
+$ make dev
+[...]
+|> {{ label }} <| app #
+```
+
+The `{{ label }}` command line application is installed in `develop` mode, therefore all changes will be live and can be tested immediately as code is modified.
+
+```
+|> {{ label }} <| app # {{ label }} --help
+```
+
+### Running Tests
+
+Execute tests from within the development environment:
+
+```
+|> {{ label }} <| app # make test
+```
+
+
+### Releasing to PyPi
+
+Before releasing to PyPi, you must configure your login credentials:
+
+**~/.pypirc**:
+
+```
+[pypi]
+username = YOUR_USERNAME
+password = YOUR_PASSWORD
+```
+
+Then use the included helper function via the `Makefile`:
+
+```
+$ make dist
+
+$ make dist-upload
+```
+
+## Deployments
+
+### Docker
+
+Included is a basic `Dockerfile` for building and distributing `{{ name }}`,
+and can be built with the included `make` helper:
+
+```
+$ make docker
+
+$ docker run -it {{ label }} --help
+usage: {{ label }} [-h] [--debug] [--quiet] [-o {json,yaml}] [-v] {command1} ...
+
+{{ description }}
+
+optional arguments:
+  -h, --help      show this help message and exit
+  --debug         toggle debug output
+  --quiet         suppress all output
+  -o {json,yaml}  output handler
+  -v, --version   show program's version number and exit
+
+sub-commands:
+  {command1}
+    command1      example sub command1
+
+Usage: {{ title }} command1 --foo bar
+```

cement/cli/templates/generate/app/config/{{ label }}.yml.example

@@ -0,0 +1,46 @@
+### {{ name }} Configuration Settings
+---
+
+{{ label }}:
+
+### Toggle application level debug (does not toggle framework debugging)
+# debug: false
+
+### Where external (third-party) plugins are loaded from
+# plugin_dir: /var/lib/{{ label }}/plugins/
+
+### Where all plugin configurations are loaded from
+# plugin_config_dir: /etc/{{ label }}/plugins.d/
+
+### Where external templates are loaded from
+# template_dir: /var/lib/{{ label }}/templates/
+
+### The log handler label
+# log_handler: colorlog
+
+### The output handler label
+# output_handler: jinja2
+
+### sample foo option
+# foo: bar
+
+
+log.colorlog:
+
+### Where the log file lives (no log file by default)
+# file: null
+
+### The level for which to log.  One of: info, warning, error, fatal, debug
+# level: info
+
+### Whether or not to log to console
+# to_console: true
+
+### Whether or not to rotate the log file when it reaches `max_bytes`
+# rotate: false
+
+### Max size in bytes that a log file can grow until it is rotated.
+# max_bytes: 512000
+
+### The maximun number of log files to maintain when rotating
+# max_files: 4

cement/cli/templates/generate/app/docker-compose.yml

@@ -0,0 +1,12 @@
+version: "3"
+services:
+    {{ label }}:
+        image: "{{ label }}:dev"
+        build:
+            context: .
+            dockerfile: docker/Dockerfile.dev
+        hostname: cement
+        stdin_open: true
+        tty: true
+        volumes:
+            - ".:/app"

cement/cli/templates/generate/app/docker/Dockerfile.dev

@@ -0,0 +1,17 @@
+FROM python:3.6-alpine
+MAINTAINER {{ creator }} <{{ creator_email }}>
+ENV PS1="\[\e[0;33m\]|> {{ label }} <| \[\e[1;35m\]\W\[\e[0m\] \[\e[0m\]\# "
+
+WORKDIR /app
+COPY requirements.txt requirements-dev.txt /app/
+RUN apk update \
+    && apk add git make \
+    && pip install -r requirements-dev.txt \
+    && rm -f /usr/local/lib/python3.6/site-packages/cement.egg-link \
+    && cd src/cement \
+    && python setup.py install \
+    && cd /app \
+    && rm -rf src/cement
+COPY . /app
+RUN python setup.py develop
+CMD ["/bin/ash"]

cement/cli/templates/generate/app/requirements-dev.txt

@@ -0,0 +1,15 @@
+-r requirements.txt
+
+pytest
+pytest-cov
+mock
+coverage
+sphinx
+pep8
+autopep8
+# version cap due to bug: https://gitlab.com/pycqa/flake8/issues/406
+pycodestyle<2.4
+flake8
+twine>=1.11.0
+setuptools>=38.6.0
+wheel>=0.31.0

cement/cli/templates/generate/app/requirements.txt

@@ -0,0 +1,6 @@
+### FIXME: Replace with 'cement==3.0.0' once it is stable
+-e git+https://github.com/datafolklabs/cement.git@portland#egg=cement
+
+jinja2
+pyyaml
+colorlog

cement/cli/templates/generate/app/setup.py

@@ -0,0 +1,28 @@
+
+from setuptools import setup, find_packages
+from {{ label }}.core.version import get_version
+
+VERSION = get_version()
+
+f = open('README.md', 'r')
+LONG_DESCRIPTION = f.read()
+f.close()
+
+setup(
+    name='{{ label }}',
+    version=VERSION,
+    description='{{ description }}',
+    long_description=LONG_DESCRIPTION,
+    long_description_content_type='text/markdown',
+    author='{{ creator }}',
+    author_email='{{ creator_email }}',
+    url='{{ url }}',
+    license='{{ license }}',
+    packages=find_packages(exclude=['ez_setup', 'tests*']),
+    package_data={'{{ label }}': ['templates/*']},
+    include_package_data=True,
+    entry_points="""
+        [console_scripts]
+        {{ label }} = {{ label }}.main:main
+    """,
+)

cement/cli/templates/generate/app/tests/conftest.py

@@ -0,0 +1,27 @@
+"""
+PyTest Fixtures.
+"""
+
+import os
+import shutil
+import pytest
+from tempfile import mkstemp, mkdtemp
+
+
+@pytest.fixture(scope="function")
+def tmp(request):
+    """
+    Create a `tmp` object that geneates a unique temporary directory, and file
+    for each test function that requires it.
+    """
+
+    class Tmp(object):
+        def __init__(self):
+            self.dir = mkdtemp()
+            _, self.file = mkstemp(dir=self.dir)
+    t = Tmp()
+    yield t
+
+    # cleanup
+    if os.path.exists(t.dir):
+        shutil.rmtree(t.dir)

cement/cli/templates/generate/app/tests/test_main.py

@@ -0,0 +1,13 @@
+
+from {{ label }}.main import {{ class_name}}Test
+
+def test_{{ label }}(tmp):
+    with {{ class_name }}Test() as app:
+        res = app.run()
+        print(res)
+        raise Exception
+
+def test_command1(tmp):
+    argv = ['command1']
+    with {{ class_name }}Test(argv=argv) as app:
+        app.run()

cement/cli/templates/generate/app/{{ label }}/bootstrap.py

@@ -0,0 +1,5 @@
+
+from .controllers.base import Base
+
+def load(app):
+    app.handler.register(Base)

cement/cli/templates/generate/app/{{ label }}/controllers/base.py

@@ -0,0 +1,61 @@
+
+from cement import Controller, ex
+from ..core.version import get_version
+
+VERSION_BANNER = """
+{{ description }}
+Version: %s
+Created by: {{ creator }}
+URL: {{ url }}
+""" % get_version()
+
+
+class Base(Controller):
+    class Meta:
+        label = 'base'
+
+        # text displayed at the top of --help output
+        description = '{{ description }}'
+
+        # text displayed at the bottom of --help output
+        epilog = 'Usage: {{ label }} command1 --foo bar'
+
+        # controller level arguments. ex: '{{ label }} --version'
+        arguments = [
+            ### add a version banner
+            ( [ '-v', '--version' ],
+              { 'action'  : 'version',
+                'version' : VERSION_BANNER } ),
+        ]
+
+
+    def _default(self):
+        """Default action if no sub-command is passed."""
+
+        self.app.args.print_help()
+
+
+    @ex(
+        help='example sub command1',
+
+        # sub-command level arguments. ex: '{{ label }} command1 --foo bar'
+        arguments=[
+            ### add a sample foo option under subcommand namespace
+            ( [ '-f', '--foo' ],
+              { 'help' : 'notorious foo option',
+                'action'  : 'store',
+                'dest' : 'foo' } ),
+        ],
+    )
+    def command1(self):
+        """Example sub-command."""
+
+        data = {
+            'foo' : 'bar',
+        }
+
+        ### do something with arguments
+        if self.app.pargs.foo is not None:
+            data['foo'] = self.app.pargs.foo
+
+        self.app.render(data, 'command1.jinja2')

cement/cli/templates/generate/app/{{ label }}/core/exc.py

@@ -0,0 +1,13 @@
+
+class {{ class_name }}Error(Exception):
+    """Generic errors."""
+
+    def __init__(self, msg):
+        Exception.__init__(self)
+        self.msg = msg
+
+    def __str__(self):
+        return self.msg
+
+    def __repr__(self):
+        return "<{{ class_name }}Error - %s>" % self.msg

cement/cli/templates/generate/app/{{ label }}/core/version.py

@@ -0,0 +1,7 @@
+
+from cement.utils.version import get_version as cement_get_version
+
+VERSION = (0, 0, 1, 'alpha', 0)
+
+def get_version(version=VERSION):
+    return cement_get_version(version)

cement/cli/templates/generate/app/{{ label }}/main.py

@@ -0,0 +1,90 @@
+
+from cement import App, init_defaults
+from cement.core.exc import CaughtSignal
+from .core.exc import {{ class_name }}Error
+
+
+# configuration defaults
+DEFAULTS = init_defaults('{{ label }}')
+DEFAULTS['{{ label }}']['{{ foo }}'] = 'bar'
+
+
+class {{ class_name }}(App):
+    """{{ name }} primary application."""
+
+    class Meta:
+        label = '{{ label }}'
+
+        # offload handler/hook registration to a separate module
+        bootstrap = '{{ label }}.bootstrap'
+
+        # configuration defaults
+        config_defaults = DEFAULTS
+
+        # load additional framework extensions
+        extensions = [
+            'json',
+            'yaml',
+            'colorlog',
+            'jinja2',
+        ]
+
+        # configuration handler
+        config_handler = 'yaml'
+
+        # configuration file suffix
+        config_file_suffix = '.yml'
+
+        # set the log handler
+        log_handler = 'colorlog'
+
+        # set the output handler
+        output_handler = 'jinja2'
+
+        # call sys.exit() on close
+        close_on_exit = True
+
+
+class {{ class_name }}Test({{ class_name}}):
+    """A test app that is better suited for testing."""
+
+    class Meta:
+        # default argv to empty (don't use sys.argv)
+        argv = []
+
+        # don't look for config files (could break tests)
+        config_files = []
+
+        # don't call sys.exit() when app.close() is called in tests
+        exit_on_close = False
+
+
+def main():
+    with {{ class_name }}() as app:
+        try:
+            app.run()
+
+        except AssertionError as e:
+            print('AssertionError > %s' % e.args[0])
+            app.exit_code = 1
+
+            if app.debug is True:
+                import traceback
+                traceback.print_exc()
+
+        except {{ class_name}}Error:
+            print('{{ class_name }}Error > %s' % e.args[0])
+            app.exit_code = 1
+
+            if app.debug is True:
+                import traceback
+                traceback.print_exc()
+
+        except CaughtSignal as e:
+            # Default Cement signals are SIGINT and SIGTERM, exit 0 (non-error)
+            print('\n%s' % e)
+            app.exit_code = 0
+
+
+if __name__ == '__main__':
+    main()

cement/cli/templates/generate/app/{{ label }}/templates/command1.jinja2

@@ -0,0 +1 @@
+Example template: Foo => {{ foo }}

cement/cli/templates/generate/extension/.generate.yml

@@ -0,0 +1,8 @@
+---
+
+variables:
+    -   name: label
+        prompt: "Extension Label"
+        default: "myextension"
+        case: lower
+        validate: "^[a-zA-Z0-9]+$"

cement/cli/templates/generate/extension/ext_{{ label }}.py

@@ -0,0 +1,12 @@
+
+from cement import minimal_logger
+
+LOG = minimal_logger(__name__)
+
+def {{ label }}_pre_run_hook(app):
+    # do something with app
+    LOG.debug('Inside {{ label }}_pre_run_hook!')
+
+def load(app):
+    # do something to extend cement
+    app.hook.register('pre_run', {{ label }}_pre_run_hook)

cement/cli/templates/generate/plugin/.generate.yml

@@ -0,0 +1,15 @@
+---
+
+exclude:
+    - '^(.*)[\/\\\\]plugin[\/\\\\]{{ label }}[\/\\\\]templates[\/\\\\](.*)$'
+
+variables:
+    -   name: label
+        prompt: "Plugin Label"
+        case: "lower"
+        default: "myplugin"
+
+    -   name: class_name
+        prompt: "Plugin Class Name"
+        validate: "^[a-zA-Z0-9]+$"
+        default: "MyPlugin"

cement/cli/templates/generate/plugin/{{ label }}/__init__.py

@@ -0,0 +1,11 @@
+
+import os
+from .controllers.{{ label }} import {{ class_name }}
+
+def add_template_dir(app):
+    path = os.path.join(os.path.dirname(__file__), 'templates')
+    app.add_template_dir(path)
+
+def load(app):
+    app.handler.register({{ class_name }})
+    app.hook.register('post_setup', add_template_dir)

cement/cli/templates/generate/plugin/{{ label }}/controllers/{{ label }}.py

@@ -0,0 +1,36 @@
+
+from cement import Controller, ex
+
+
+class {{ class_name }}(Controller):
+
+    class Meta:
+        label = '{{ label }}'
+        stacked_on = 'base'
+        stacked_type = 'nested'
+
+    def _default(self):
+        self._parser.print_help()
+
+    @ex(
+        help='example sub command1',
+        arguments=[
+            ### add a sample foo option under subcommand namespace
+            ( [ '-f', '--foo' ],
+              { 'help' : 'notorious foo option',
+                'action'  : 'store',
+                'dest' : 'foo' } ),
+        ],
+    )
+    def command1(self):
+        """Example sub-command."""
+
+        data = {
+            'foo' : 'bar',
+        }
+
+        ### do something with arguments
+        if self.app.pargs.foo is not None:
+            data['foo'] = self.app.pargs.foo
+
+        self.app.render(data, 'plugins/{{ label }}/command1.jinja2')

cement/cli/templates/generate/plugin/{{ label }}/templates/plugins/{{ label }}/command1.jinja2

@@ -0,0 +1 @@
+Example template: Foo => {{ foo }}

cement/cli/templates/generate/script/.generate.yml

@@ -0,0 +1,7 @@
+---
+
+variables:
+    -   name: label
+        prompt: "Script Name"
+        default: "myscript"
+        validate: "^[a-zA-Z0-9]+$"

cement/cli/templates/generate/script/{{ label }}.py

@@ -0,0 +1,75 @@
+
+from cement import App, CaughtSignal, Controller, ex, get_version
+
+VERSION = (0, 0, 1, 'alpha', 0)
+
+VERSION_BANNER = """
+{{ label }} v%s
+""" % get_version()
+
+
+class Base(Controller):
+    class Meta:
+        label = 'base'
+
+        arguments = [
+            ### add a version banner
+            ( [ '-v', '--version' ],
+              { 'action'  : 'version',
+                'version' : VERSION_BANNER } ),
+        ]
+
+
+    def _default(self):
+        """Default action if no sub-command is passed."""
+
+        self.app.args.print_help()
+
+
+    @ex(
+        help='example sub command1',
+        arguments=[
+            ### add a sample foo option under subcommand namespace
+            ( [ '-f', '--foo' ],
+              { 'help' : 'notorious foo option',
+                'action'  : 'store',
+                'dest' : 'foo' } ),
+        ],
+    )
+    def command1(self):
+        """Example sub-command."""
+
+        print('Inside Base.command1')
+
+        ### do something with arguments
+        if self.app.pargs.foo is not None:
+            print('Foo Argument > %s' % self.app.pargs.foo)
+
+
+class MyApp(App):
+
+    class Meta:
+        # application label
+        label = '{{ label }}'
+
+        # register handlers
+        handlers = [
+            Base
+        ]
+
+        # call sys.exit() on close
+        close_on_exit = True
+
+
+def main():
+    with MyApp() as app:
+        try:
+            app.run()
+        except CaughtSignal as e:
+            # Default Cement signals are SIGINT and SIGTERM, exit 0 (non-error)
+            print('\n%s' % e)
+            app.exit_code = 0
+
+
+if __name__ == '__main__':
+    main()

cement/core/template.py

@@ -102,13 +102,13 @@ class TemplateHandler(TemplateHandlerBase):
     """
 
     class Meta:
-        # Unique identifier (str), used internally.
+        #: Unique identifier (str), used internally.
         label = None
 
-        # The interface that this handler implements.
+        #: The interface that this handler implements.
         interface = 'template'
 
-        # List of file patterns to exclude
+        #: List of file patterns to exclude (copy but not render as template)
         exclude = [
             '^(.*)\.png$',
             '^(.*)\.jpg$',
@@ -125,20 +125,68 @@ class TemplateHandler(TemplateHandlerBase):
             '^(.*)\.pyc$',
         ]
 
+        #: List of file patterns to ignore completely (not copy at all)
+        ignore = None
+
+    def __init__(self, *args, **kwargs):
+        super(TemplateHandler, self).__init__(*args, **kwargs)
+        if self._meta.ignore is None:
+            self._meta.ignore = []
+        if self._meta.exclude is None:
+            self._meta.exclude = []
+
     def render(self, content, data):
+        """
+        Render ``content`` as template using using the ``data`` dictionary.
+
+        Args:
+            content (str): The content to render.
+            data (dict): The data dictionary to interpolate in the template.
+
+        Returns:
+            str: The rendered content.
+        """
+
         # must be provided by a subclass
         raise NotImplemented
 
-    def copy(self, src, dest, data):
+    def copy(self, src, dest, data, force=False, exclude=None, ignore=None):
+        """
+        Render ``src`` directory as template, including directory and file
+        names, and copy to ``dest`` directory.
+
+        Args:
+            src (str): The source directory path.
+            dest (str): The destination directory path.
+            data (dict): The data dictionary to interpolate in the template.
+            force (bool): Whether to overwrite existing files.
+            exclude (list): List of regular expressions to match files that
+                should only be copied, and not rendered as template.
+            ignore (list): List of regular expressions to match files that
+                should be completely ignored and not copied at all.
+
+        Returns:
+            bool: Returns ``True`` if the copy completed successfully.
+
+        Raises:
+            AssertionError: If the ``src`` template directory path does not
+                exists, and when a ``dest`` file already exists and
+                ``force is not True``.
+        """
+
         dest = fs.abspath(dest)
         src = fs.abspath(src)
+        if exclude is None:
+            exclude = []
+        if ignore is None:
+            ignore = []
 
         assert os.path.exists(src), "Source path %s does not exist!" % src
 
         if not os.path.exists(dest):
             os.makedirs(dest)
 
-        self.app.log.info('Copying source template %s -> %s' % (src, dest))
+        self.app.log.debug('Copying source template %s -> %s' % (src, dest))
 
         # here's the fun
         for cur_dir, sub_dirs, files in os.walk(src):
@@ -174,25 +222,41 @@ class TemplateHandler(TemplateHandlerBase):
 
             for _file in files:
                 self.app.log.debug('rendering template %s' % _file)
-                new_file = re.sub(src,
-                                  '',
-                                  self.render(_file, data))
-                _file_dest = os.path.join(cur_dir_dest, new_file)
+                new_file = re.sub(src, '', self.render(_file, data))
+                _file = fs.abspath(os.path.join(cur_dir, _file))
+                _file_dest = fs.abspath(os.path.join(cur_dir_dest, new_file))
 
-                assert not os.path.exists(_file_dest), \
-                    'Destination file already exists: %s ' % _file_dest
+                if force is True:
+                    LOG.debug('Overwriting existing file: %s ' % _file_dest)
+                else:
+                    assert not os.path.exists(_file_dest), \
+                        'Destination file already exists: %s ' % _file_dest
 
-                exclude = False
-                for pattern in self._meta.exclude:
+                ignore_it = False
+                all_patterns = self._meta.ignore + ignore
+                for pattern in all_patterns:
                     if re.match(pattern, _file):
-                        exclude = True
+                        ignore_it = True
                         break
 
-                if exclude is True:
-                    self.app.log.warn(
+                if ignore_it is True:
+                    self.app.log.debug(
+                        'Not copying ignored file: ' +
+                        '%s' % _file)
+                    continue
+
+                exclude_it = False
+                all_patterns = self._meta.exclude + exclude
+                for pattern in all_patterns:
+                    if re.match(pattern, _file):
+                        exclude_it = True
+                        break
+
+                if exclude_it is True:
+                    self.app.log.debug(
                         'Not rendering excluded file as template: ' +
-                        '%s' % os.path.join(cur_dir, _file))
-                    shutil.copy(os.path.join(cur_dir, _file), _file_dest)
+                        '%s' % _file)
+                    shutil.copy(_file, _file_dest)
                 else:
                     f = open(os.path.join(cur_dir, _file), 'r')
                     content = f.read()

cement/ext/ext_generate.py

@@ -0,0 +1,297 @@
+"""
+The Generate Extension provides a mechanism for generating common content
+from template directories.  Example use case would be the ability for
+application developers to easily generate new plugins for their application...
+or similar in other applications such as Chef Software's
+``chef generate cookbook`` type utilities.
+
+The Cement CLI uses this extension to generate apps, plugins, extensions, and
+scripts for developers building their applications on the framework.
+
+**Requirements**
+
+ * pyYaml (``pip install pyYaml``)
+ * A valid TemplateHandler must be defined at the application level via
+   ``App.Meta.template_handler`` such as ``jinja2``, ``mustache``, etc.
+
+
+**Configuration**
+
+This extension does not currently honor any application configuration settings.
+
+**App Meta Data**
+
+This extension honors the following ``App.Meta`` options:
+
+* **template_handler**: A handler class that implements the Template interface.
+* **template_dirs**: A list of data directories to look for templates.
+* **template_module**: A python module to look for templates.
+
+**Example**
+
+.. code-block:: python
+
+    from cement import App
+
+    class MyApp(App):
+        class Meta:
+            label = 'myapp'
+            extensions = ['generate', 'jinja2']
+            template_handler = 'jinja2'
+
+
+    with MyApp() as app:
+        app.run()
+
+
+Looks like:
+
+.. code-block:: console
+
+    $ python myapp.py --help
+    usage: myapp [-h] [--debug] [--quiet] {generate} ...
+
+    optional arguments:
+      -h, --help  show this help message and exit
+      --debug     toggle debug output
+      --quiet     suppress all output
+
+    sub-commands:
+      {generate}
+        generate  generate controller
+
+
+    $ python myapp.py generate --help
+    usage: myapp generate [-h] {plugin} ...
+
+    optional arguments:
+      -h, --help  show this help message and exit
+
+    sub-commands:
+      {plugin}
+        plugin      generate plugin from template
+
+
+**Generate Templates**
+
+The Generate Extension looks for a ``generate`` sub-directory in all defined
+template directory paths defined at the application level.  If it finds a
+``generate`` directory it treats all items within that directory as a
+generate template.
+
+A Generate Template requires a single configuration YAML file called
+``.generate.yml`` that looks something like:
+
+.. code-block:: yaml
+
+    ---
+
+    ignore:
+        - "^(.*)ignore-this(.*)$"
+        - "^(.*)ignore-that(.*)$"
+
+    exclude:
+        - "^(.*)exclude-this(.*)$"
+        - "^(.*)exclude-that(.*)$"
+
+    variables:
+        - name: 'my_variable_name'
+          prompt: 'The Prompt Displayed to The User'
+
+**Generate Template Configuration**
+
+The following configurations are supported in a generate template's config:
+
+* **ignore**: A list of regular expressions to match files that you want to
+  completely ignore.
+* **exclude**: A list of regular expressions to match files that you want to
+  copy, but not render as a template.
+* **variables**: A list of variable definitions that support the following
+  sub-keys:
+    * **name** *(required)*: The variable name (how it will be used in the
+      template).
+    * **prompt** *(required)*: The text displayed to the user to prompt for the
+      value of ``name``.
+    * **validate**: A single regular expression to validate the input value
+      with.
+    * **case**: A case modifyer to apply to the input value.  Valid options
+      are: ``lower``, ``upper``, ``title``.
+"""
+
+import re
+import os
+import inspect
+import yaml
+from .. import Controller, minimal_logger, shell, FrameworkError
+
+LOG = minimal_logger(__name__)
+
+
+class GenerateTemplateAbstractBase(Controller):
+    class Meta:
+        pass
+
+    def _default(self):
+        source = self._meta.source_path
+        dest = self.app.pargs.dest
+        msg = 'Generating %s %s in %s' % (
+                   self.app._meta.label, self._meta.label, dest
+               )
+        self.app.log.info(msg)
+        data = {}
+
+        f = open(os.path.join(source, '.generate.yml'))
+        g_config = yaml.load(f)
+        f.close()
+
+        vars = g_config.get('variables', {})
+        exclude_list = g_config.get('exclude', [])
+        ignore_list = g_config.get('ignore', [])
+
+        # default ignore the .generate.yml config
+        g_config_yml = '^(.*)[\/\\\\]%s[\/\\\\]\.generate\.yml$' % \
+                       self._meta.label
+        ignore_list.append(g_config_yml)
+
+        var_defaults = {
+            'name': None,
+            'prompt': None,
+            'validate': None,
+            'case': None,
+            'default': None,
+        }
+
+        for defined_var in vars:
+            var = var_defaults.copy()
+            var.update(defined_var)
+            for key in ['name', 'prompt']:
+                assert var[key] is not None, \
+                    "Required generate config key missing: %s" % key
+
+            val = None
+            if var['default'] is not None and self.app.pargs.defaults:
+                val = var['default']
+
+            elif 'default' is not None:
+                default_text = ' [%s]' % var['default']
+
+            else:
+                default_text = ''
+
+            if val is None:
+                class MyPrompt(shell.Prompt):
+                    class Meta:
+                        text = "%s%s:" % (var['prompt'], default_text)
+                        default = var.get('default', None)
+
+                p = MyPrompt()
+                val = p.prompt()
+
+            if var['case'] in ['lower', 'upper', 'title']:
+                val = getattr(val, var['case'])()
+            elif var['case'] is not None:
+                self.app.log.warning(
+                    "Invalid configuration for variable " +
+                    "'%s': " % var['name'] +
+                    "case must be one of lower, upper, or title."
+                )
+
+            if var['validate'] is not None:
+                assert re.match(var['validate'], val), \
+                    "Invalid Response (must match: '%s')" % var['validate']
+
+            data[var['name']] = val
+
+        try:
+            self.app.template.copy(source, dest, data,
+                                   force=self.app.pargs.force,
+                                   ignore=ignore_list,
+                                   exclude=exclude_list)
+        except AssertionError as e:
+            if re.match('(.*)already exists(.*)', e.args[0]):
+                raise AssertionError(e.args[0] + ' (try: --force)')
+            else:
+                raise
+
+
+def setup_template_items(app):
+    template_dirs = []
+    template_items = []
+
+    # nothing will work without a base controller
+    try:
+        assert app._meta.base_controller is not None, \
+            "The ext.generate extension requires an application base " + \
+            "controller, but none is defined!"
+    except AssertionError as e:
+        raise FrameworkError(e.args[0])
+
+    # look in app template dirs
+    for path in app._meta.template_dirs:
+        subdir_path = os.path.join(path, 'generate')
+        if os.path.exists(subdir_path):
+            template_dirs.append(subdir_path)
+
+    # use app template module, find it's path on filesystem
+    if app._meta.template_module is not None:
+        mod_parts = app._meta.template_module.split('.')
+        mod = mod_parts.pop()
+        try:
+            mod = app.__import__(mod, from_module='.'.join(mod_parts))
+            mod_path = os.path.dirname(inspect.getfile(mod))
+            subdir_path = os.path.join(mod_path, 'generate')
+            if os.path.exists(subdir_path):
+                template_dirs.append(subdir_path)
+        except AttributeError as e:
+            msg = 'unable to load template module' + \
+                  '%s from %s' % (mod, '.'.join(mod_parts))
+            app.log.debug(msg)
+
+    for path in template_dirs:
+        for item in os.listdir(path):
+            if item not in template_items:
+                template_items.append(item)
+
+            class GenerateTemplate(GenerateTemplateAbstractBase):
+                class Meta:
+                    label = item
+                    stacked_on = 'generate'
+                    stacked_type = 'nested'
+                    help = 'generate %s from template' % item
+                    arguments = [
+                        # ------------------------------------------------------
+                        (['dest'],
+                         {'help': 'destination directory path'}),
+                        # ------------------------------------------------------
+                        (['-f', '--force'],
+                         {'help': 'force operation if destination exists',
+                          'dest': 'force',
+                          'action': 'store_true'}),
+                        # ------------------------------------------------------
+                        (['-D', '--defaults'],
+                         {'help': 'use all default variable values',
+                          'dest': 'defaults',
+                          'action': 'store_true'}),
+                    ]
+                    source_path = os.path.join(path, item)
+
+            app.handler.register(GenerateTemplate)
+
+
+class Generate(Controller):
+    class Meta:
+        label = 'generate'
+        stacked_on = 'base'
+        stacked_type = 'nested'
+        config_section = 'generate'
+
+    def _setup(self, app):
+        super(Generate, self)._setup(app)
+
+    def _default(self):
+        self._parser.print_help()
+
+
+def load(app):
+    app.handler.register(Generate)
+    app.hook.register('pre_run', setup_template_items)

cement/ext/ext_jinja2.py

@@ -217,6 +217,7 @@ class Jinja2TemplateHandler(TemplateHandler):
             str: The rendered template text
 
         """
+        LOG.debug("rendering output as text via %s" % self.__module__)
 
         if not isinstance(content, str):
             content = content.decode('utf-8')

doc/source/api/ext/ext_generate.rst

@@ -0,0 +1,9 @@
+.. _cement.ext.ext_generate:
+
+:mod:`cement.ext.ext_generate`
+==============================================================================
+
+.. automodule:: cement.ext.ext_generate
+    :members:
+    :private-members:
+    :show-inheritance:

doc/source/api/ext/index.rst

@@ -11,6 +11,7 @@ Extension Modules
    ext_configparser
    ext_daemon
    ext_dummy
+   ext_generate
    ext_handlebars
    ext_jinja2
    ext_json

setup.cfg

@@ -1,15 +1,3 @@
-[nosetests]
-verbosity=2
-debug=0
-detailed-errors=1
-with-coverage=1
-cover-package=cement
-cover-inclusive=1
-cover-erase=1
-cover-html=1
-cover-html-dir=coverage_report/
-where=tests/
-
 [build_sphinx]
 source-dir = doc/source
 build-dir  = doc/build
@@ -17,3 +5,6 @@ all_files  = 1
 
 [tool:pytest]
 python_files=test_*.py
+
+[flake8]
+exclude = .git,cement/cli/templates,cement/cli/contrib

setup.py

@@ -5,48 +5,27 @@ from cement.utils import version
 
 VERSION = version.get_version()
 
-LONG = """
-Cement is an advanced CLI Application Framework for Python.  Its goal is to
-introduce a standard, and feature-full platform for both simple and complex
-command line applications as well as support rapid development needs without
-sacrificing quality.
-
-For more information please visit the official site at:
-
-    * http://builtoncement.com/
-
-"""
-
-DEPS = [
-    ### Required to build documentation
-    # "Sphinx >= 1.0",
-    ### Required for testing
-    # "nose",
-    # "coverage",
-    ]
-
-# Python < 2.7/3.2 require argparse
-if (sys.version_info[0] < 3 and sys.version_info < (2, 7)) or \
-   (sys.version_info[0] >= 3 and sys.version_info < (3, 2)):
-    DEPS.append('argparse')
+f = open('README.md', 'r')
+LONG = f.read()
+f.close()
 
 setup(name='cement',
     version=VERSION,
-    description="CLI Application Framework for Python",
+    description='CLI Application Framework for Python',
     long_description=LONG,
+    long_description_content_type='text/markdown',
     classifiers=[],
     keywords='cli framework',
     author='Data Folk Labs, LLC',
-    author_email='team@datafolklabs.com',
+    author_email='derks@datafolklabs.com',
     url='http://builtoncement.org',
     license='BSD',
     packages=find_packages(exclude=['ez_setup', 'tests*']),
     include_package_data=True,
     zip_safe=False,
     test_suite='nose.collector',
-    install_requires=DEPS,
-    setup_requires=[],
     entry_points="""
+        [console_scripts]
+        cement = cement.cli.main:main
     """,
-    namespace_packages=[],
-    )
+)