Make the fuchsia mojo/public repo the source of truth.

mojo/public/third_party/jinja2/meta.py

-# -*- 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) 2010 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
-
-
-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 pull_locals(self, frame):
-        """Remember all undeclared identifiers."""
-        self.undeclared_identifiers.update(frame.identifiers.undeclared)
-
-
-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'])
-
-    .. 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