733 lines
28 KiB
Python
733 lines
28 KiB
Python
# -*- 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) 2010 by the Jinja Team.
|
|
:license: BSD, see LICENSE for more details.
|
|
"""
|
|
import re
|
|
|
|
from operator import itemgetter
|
|
from collections import deque
|
|
from jinja2.exceptions import TemplateSyntaxError
|
|
from jinja2.utils import LRUCache
|
|
from jinja2._compat import next, iteritems, implements_iterator, text_type, \
|
|
intern
|
|
|
|
|
|
# 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+')
|
|
|
|
# we use the unicode identifier rule if this python version is able
|
|
# to handle unicode identifiers, otherwise the standard ASCII one.
|
|
try:
|
|
compile('föö', '<unknown>', 'eval')
|
|
except SyntaxError:
|
|
name_re = re.compile(r'\b[a-zA-Z_][a-zA-Z0-9_]*\b')
|
|
else:
|
|
from jinja2 import _stringdefs
|
|
name_re = re.compile(r'[%s][%s]*' % (_stringdefs.xid_start,
|
|
_stringdefs.xid_continue))
|
|
|
|
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_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"""
|
|
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('(?:\-%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('\-%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('(.*?)((?:\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)
|
|
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)
|
|
# if we can express it as bytestring (ascii only)
|
|
# we do that for support of semi broken APIs
|
|
# as datetime.datetime.strftime. On python 3 this
|
|
# call becomes a noop thanks to 2to3
|
|
try:
|
|
value = str(value)
|
|
except UnicodeError:
|
|
pass
|
|
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)
|