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# -*- coding: utf-8 -*-
"""
sphinx.util.tags
~~~~~~~~~~~~~~~~
:copyright: Copyright 2007-2014 by the Sphinx team, see AUTHORS.
:license: BSD, see LICENSE for details.
"""
import warnings
# jinja2.sandbox imports the sets module on purpose
warnings.filterwarnings('ignore', 'the sets module', DeprecationWarning,
module='jinja2.sandbox')
# (ab)use the Jinja parser for parsing our boolean expressions
from jinja2 import nodes
from jinja2.parser import Parser
from jinja2.environment import Environment
env = Environment()
class BooleanParser(Parser):
"""
Only allow condition exprs and/or/not operations.
"""
def parse_compare(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 == 'lparen':
next(self.stream)
node = self.parse_expression()
self.stream.expect('rparen')
else:
self.fail("unexpected token '%s'" % (token,), token.lineno)
return node
class Tags(object):
def __init__(self, tags=None):
self.tags = dict.fromkeys(tags or [], True)
def has(self, tag):
return tag in self.tags
__contains__ = has
def __iter__(self):
return iter(self.tags)
def add(self, tag):
self.tags[tag] = True
def remove(self, tag):
self.tags.pop(tag, None)
def eval_condition(self, condition):
# exceptions are handled by the caller
parser = BooleanParser(env, condition, state='variable')
expr = parser.parse_expression()
if not parser.stream.eos:
raise ValueError('chunk after expression')
def eval_node(node):
if isinstance(node, nodes.CondExpr):
if eval_node(node.test):
return eval_node(node.expr1)
else:
return eval_node(node.expr2)
elif isinstance(node, nodes.And):
return eval_node(node.left) and eval_node(node.right)
elif isinstance(node, nodes.Or):
return eval_node(node.left) or eval_node(node.right)
elif isinstance(node, nodes.Not):
return not eval_node(node.node)
elif isinstance(node, nodes.Name):
return self.tags.get(node.name, False)
else:
raise ValueError('invalid node, check parsing')
return eval_node(expr)
|
