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# -*- coding: utf-8 -*-
"""
jinja2.parser
~~~~~~~~~~~~~
Implements the template parser.
:copyright: 2008 by Armin Ronacher.
:license: BSD, see LICENSE for more details.
"""
from jinja2 import nodes
from jinja2.exceptions import TemplateSyntaxError, TemplateAssertionError
_statement_keywords = frozenset(['for', 'if', 'block', 'extends', 'print',
'macro', 'include', 'from', 'import',
'set'])
_compare_operators = frozenset(['eq', 'ne', 'lt', 'lteq', 'gt', 'gteq'])
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.extensions.itervalues():
for tag in extension.tags:
self.extensions[tag] = extension.parse
self._last_identifier = 0
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 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 is not 'name':
self.fail('tag name expected', token.lineno)
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)
self.fail('unknown tag %r' % token.value, token.lineno)
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)
if drop_needle:
self.stream.next()
return result
def parse_set(self):
"""Parse an assign statement."""
lineno = self.stream.next().lineno
target = self.parse_assign_target()
self.stream.expect('assign')
expr = self.parse_tuple()
return nodes.Assign(target, expr, 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 self.stream.next().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'))
token = self.stream.next()
if token.test('name:elif'):
new_node = nodes.If(lineno=self.stream.current.lineno)
node.else_ = [new_node]
node = new_node
continue
elif token.test('name:else'):
node.else_ = self.parse_statements(('name:endif',),
drop_needle=True)
else:
node.else_ = []
break
return result
def parse_block(self):
node = nodes.Block(lineno=self.stream.next().lineno)
node.name = self.stream.expect('name').value
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=self.stream.next().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 = self.stream.next().value == 'with'
self.stream.skip()
else:
node.with_context = default
return node
def parse_include(self):
node = nodes.Include(lineno=self.stream.next().lineno)
node.template = self.parse_expression()
return self.parse_import_context(node, True)
def parse_import(self):
node = nodes.Import(lineno=self.stream.next().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=self.stream.next().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 = self.stream.next().value == 'with'
self.stream.skip()
return True
return False
while 1:
if node.names:
self.stream.expect('comma')
if self.stream.current.type is '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 is not 'comma':
break
else:
break
if not hasattr(node, 'with_context'):
node.with_context = False
self.stream.skip_if('comma')
return node
def parse_signature(self, node):
node.args = args = []
node.defaults = defaults = []
self.stream.expect('lparen')
while self.stream.current.type is not '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())
args.append(arg)
self.stream.expect('rparen')
def parse_call_block(self):
node = nodes.CallBlock(lineno=self.stream.next().lineno)
if self.stream.current.type is '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=self.stream.next().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=self.stream.next().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=self.stream.next().lineno)
node.nodes = []
while self.stream.current.type is not '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):
"""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 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(with_postfix=False)
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_compare()
while self.stream.skip_if('name:and'):
right = self.parse_compare()
left = nodes.And(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_compare(self):
lineno = self.stream.current.lineno
expr = self.parse_add()
ops = []
while 1:
token_type = self.stream.current.type
if token_type in _compare_operators:
self.stream.next()
ops.append(nodes.Operand(token_type, self.parse_add()))
elif self.stream.skip_if('name:in'):
ops.append(nodes.Operand('in', self.parse_add()))
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_add()))
else:
break
lineno = self.stream.current.lineno
if not ops:
return expr
return nodes.Compare(expr, ops, lineno=lineno)
def parse_add(self):
lineno = self.stream.current.lineno
left = self.parse_sub()
while self.stream.current.type is 'add':
self.stream.next()
right = self.parse_sub()
left = nodes.Add(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_sub(self):
lineno = self.stream.current.lineno
left = self.parse_concat()
while self.stream.current.type is 'sub':
self.stream.next()
right = self.parse_concat()
left = nodes.Sub(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_concat(self):
lineno = self.stream.current.lineno
args = [self.parse_mul()]
while self.stream.current.type is 'tilde':
self.stream.next()
args.append(self.parse_mul())
if len(args) == 1:
return args[0]
return nodes.Concat(args, lineno=lineno)
def parse_mul(self):
lineno = self.stream.current.lineno
left = self.parse_div()
while self.stream.current.type is 'mul':
self.stream.next()
right = self.parse_div()
left = nodes.Mul(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_div(self):
lineno = self.stream.current.lineno
left = self.parse_floordiv()
while self.stream.current.type is 'div':
self.stream.next()
right = self.parse_floordiv()
left = nodes.Div(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_floordiv(self):
lineno = self.stream.current.lineno
left = self.parse_mod()
while self.stream.current.type is 'floordiv':
self.stream.next()
right = self.parse_mod()
left = nodes.FloorDiv(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_mod(self):
lineno = self.stream.current.lineno
left = self.parse_pow()
while self.stream.current.type is 'mod':
self.stream.next()
right = self.parse_pow()
left = nodes.Mod(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 is 'pow':
self.stream.next()
right = self.parse_unary()
left = nodes.Pow(left, right, lineno=lineno)
lineno = self.stream.current.lineno
return left
def parse_unary(self):
token_type = self.stream.current.type
lineno = self.stream.current.lineno
if token_type is 'name' and self.stream.current.value == 'not':
self.stream.next()
node = self.parse_unary()
return nodes.Not(node, lineno=lineno)
if token_type is 'sub':
self.stream.next()
node = self.parse_unary()
return nodes.Neg(node, lineno=lineno)
if token_type is 'add':
self.stream.next()
node = self.parse_unary()
return nodes.Pos(node, lineno=lineno)
return self.parse_primary()
def parse_primary(self, with_postfix=True):
token = self.stream.current
if token.type is '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)
self.stream.next()
elif token.type is 'string':
self.stream.next()
buf = [token.value]
lineno = token.lineno
while self.stream.current.type is 'string':
buf.append(self.stream.current.value)
self.stream.next()
node = nodes.Const(''.join(buf), lineno=lineno)
elif token.type in ('integer', 'float'):
self.stream.next()
node = nodes.Const(token.value, lineno=token.lineno)
elif token.type is 'lparen':
self.stream.next()
node = self.parse_tuple()
self.stream.expect('rparen')
elif token.type is 'lbracket':
node = self.parse_list()
elif token.type is 'lbrace':
node = self.parse_dict()
else:
self.fail("unexpected token '%s'" % (token,), token.lineno)
if with_postfix:
node = self.parse_postfix(node)
return node
def parse_tuple(self, simplified=False, with_condexpr=True,
extra_end_rules=None):
"""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']``.
"""
lineno = self.stream.current.lineno
if simplified:
parse = lambda: self.parse_primary(with_postfix=False)
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 is 'comma':
is_tuple = True
else:
break
lineno = self.stream.current.lineno
if not is_tuple and args:
return args[0]
return nodes.Tuple(args, 'load', lineno=lineno)
def parse_list(self):
token = self.stream.expect('lbracket')
items = []
while self.stream.current.type is not '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 is not '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 is 'dot' or token_type is 'lbracket':
node = self.parse_subscript(node)
elif token_type is 'lparen':
node = self.parse_call(node)
elif token_type is 'pipe':
node = self.parse_filter(node)
elif token_type is 'name' and self.stream.current.value == 'is':
node = self.parse_test(node)
else:
break
return node
def parse_subscript(self, node):
token = self.stream.next()
if token.type is 'dot':
attr_token = self.stream.current
self.stream.next()
if attr_token.type is 'name':
return nodes.Getattr(node, attr_token.value, 'load',
lineno=token.lineno)
elif attr_token.type is not '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 is 'lbracket':
priority_on_attribute = False
args = []
while self.stream.current.type is not '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, self.lineno, self.filename)
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 is 'colon':
self.stream.next()
args = [None]
else:
node = self.parse_expression()
if self.stream.current.type is not 'colon':
return node
self.stream.next()
args = [node]
if self.stream.current.type is '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 is 'colon':
self.stream.next()
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 is not 'rparen':
if require_comma:
self.stream.expect('comma')
# support for trailing comma
if self.stream.current.type is 'rparen':
break
if self.stream.current.type is 'mul':
ensure(dyn_args is None and dyn_kwargs is None)
self.stream.next()
dyn_args = self.parse_expression()
elif self.stream.current.type is 'pow':
ensure(dyn_kwargs is None)
self.stream.next()
dyn_kwargs = self.parse_expression()
else:
ensure(dyn_args is None and dyn_kwargs is None)
if self.stream.current.type is 'name' and \
self.stream.look().type is '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:
self.stream.next()
token = self.stream.expect('name')
name = token.value
while self.stream.current.type is 'dot':
self.stream.next()
name += '.' + self.stream.expect('name').value
if self.stream.current.type is '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 = self.stream.next()
if self.stream.current.test('name:not'):
self.stream.next()
negated = True
else:
negated = False
name = self.stream.expect('name').value
while self.stream.current.type is 'dot':
self.stream.next()
name += '.' + self.stream.expect('name').value
dyn_args = dyn_kwargs = None
kwargs = []
if self.stream.current.type is '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_expression()]
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
def flush_data():
if data_buffer:
lineno = data_buffer[0].lineno
body.append(nodes.Output(data_buffer[:], lineno=lineno))
del data_buffer[:]
while self.stream:
token = self.stream.current
if token.type is 'data':
if token.value:
add_data(nodes.TemplateData(token.value,
lineno=token.lineno))
self.stream.next()
elif token.type is 'variable_begin':
self.stream.next()
add_data(self.parse_tuple(with_condexpr=True))
self.stream.expect('variable_end')
elif token.type is 'block_begin':
flush_data()
self.stream.next()
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()
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
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