Current File : //lib/python3/dist-packages/cssutils/tokenize2.py
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""New CSS Tokenizer (a generator)
"""
__all__ = ['Tokenizer', 'CSSProductions']
__docformat__ = 'restructuredtext'
__version__ = '$Id$'
from .cssproductions import *
from .helper import normalize
import itertools
import re
import sys
_TOKENIZER_CACHE = {}
class Tokenizer(object):
"""
generates a list of Token tuples:
(Tokenname, value, startline, startcolumn)
"""
_atkeywords = {
'@font-face': CSSProductions.FONT_FACE_SYM,
'@import': CSSProductions.IMPORT_SYM,
'@media': CSSProductions.MEDIA_SYM,
'@namespace': CSSProductions.NAMESPACE_SYM,
'@page': CSSProductions.PAGE_SYM,
'@variables': CSSProductions.VARIABLES_SYM
}
_linesep = '\n'
unicodesub = re.compile(r'\\[0-9a-fA-F]{1,6}(?:\r\n|[\t\r\n\f\x20])?').sub
cleanstring = re.compile(r'\\((\r\n)|[\n\r\f])').sub
def __init__(self, macros=None, productions=None, doComments=True):
"""
inits tokenizer with given macros and productions which default to
cssutils own macros and productions
"""
if isinstance(macros, dict):
macros_hash_key = sorted(macros.items())
else:
macros_hash_key = macros
hash_key = str((macros_hash_key, productions))
if hash_key in _TOKENIZER_CACHE:
(tokenmatches, commentmatcher, urimatcher) = _TOKENIZER_CACHE[hash_key]
else:
if not macros:
macros = MACROS
if not productions:
productions = PRODUCTIONS
tokenmatches = self._compile_productions(self._expand_macros(macros,
productions))
commentmatcher = [x[1] for x in tokenmatches if x[0] == 'COMMENT'][0]
urimatcher = [x[1] for x in tokenmatches if x[0] == 'URI'][0]
_TOKENIZER_CACHE[hash_key] = (tokenmatches, commentmatcher, urimatcher)
self.tokenmatches = tokenmatches
self.commentmatcher = commentmatcher
self.urimatcher = urimatcher
self._doComments = doComments
self._pushed = []
def _expand_macros(self, macros, productions):
"""returns macro expanded productions, order of productions is kept"""
def macro_value(m):
return '(?:%s)' % macros[m.groupdict()['macro']]
expanded = []
for key, value in productions:
while re.search(r'{[a-zA-Z][a-zA-Z0-9-]*}', value):
value = re.sub(r'{(?P<macro>[a-zA-Z][a-zA-Z0-9-]*)}',
macro_value, value)
expanded.append((key, value))
return expanded
def _compile_productions(self, expanded_productions):
"""compile productions into callable match objects, order is kept"""
compiled = []
for key, value in expanded_productions:
compiled.append((key, re.compile('(?:%s)' % value, re.U).match))
return compiled
def push(self, *tokens):
"""Push back tokens which have been pulled but not processed."""
self._pushed = itertools.chain(tokens, self._pushed)
def clear(self):
self._pushed = []
def tokenize(self, text, fullsheet=False):
"""Generator: Tokenize text and yield tokens, each token is a tuple
of::
(name, value, line, col)
The token value will contain a normal string, meaning CSS unicode
escapes have been resolved to normal characters. The serializer
escapes needed characters back to unicode escapes depending on
the stylesheet target encoding.
text
to be tokenized
fullsheet
if ``True`` appends EOF token as last one and completes incomplete
COMMENT or INVALID (to STRING) tokens
"""
def _repl(m):
"used by unicodesub"
num = int(m.group(0)[1:], 16)
if num <= sys.maxunicode:
return chr(num)
else:
return m.group(0)
def _normalize(value):
"normalize and do unicodesub"
return normalize(self.unicodesub(_repl, value))
line = col = 1
# The current starting character. We just increase this instead of
# splitting off the beginning of text to increase performance.
pos = 0
# check for BOM first as it should only be max one at the start
(BOM, matcher), productions = self.tokenmatches[0], self.tokenmatches[1:]
match = matcher(text, pos)
if match:
found = match.group(0)
yield (BOM, found, line, col)
pos += len(found)
# check for @charset which is valid only at start of CSS
if has_at(text, pos, '@charset '):
found = '@charset ' # production has trailing S!
yield (CSSProductions.CHARSET_SYM, found, line, col)
pos += len(found)
col += len(found)
# Avoid repeated function call
_len_text = len(text)
_orig_text = text
while pos < _len_text:
# do pushed tokens before new ones
for pushed in self._pushed:
yield pushed
# speed test for most used CHARs, sadly . not possible :(
c = text[pos]
if c in ',:;{}>[]': # + but in num!
yield ('CHAR', c, line, col)
col += 1
pos += 1
else:
# check all other productions, at least CHAR must match
for name, matcher in productions:
# TODO: USE bad comment?
if (fullsheet and name == 'CHAR' and
has_at(text, pos, '/*')):
# before CHAR production test for incomplete comment
possiblecomment = '%s*/' % text[pos:]
match = self.commentmatcher(possiblecomment)
if match and self._doComments:
yield ('COMMENT', possiblecomment, line, col)
pos = _len_text # ate all remaining text
break
match = matcher(text, pos) # if no match try next production
if match:
found = match.group(0) # needed later for line/col
# The ident regex also matches the beginning of
# functions, but we can't put the function regex before
# the ident regex, as otherwise 'and(' is recognized as
# function (even though it is valid in media queries).
# So we're doing this: if we find an ident, but the next
# character is a open parenthesis, we instead skip and
# let the FUNCTION production take over - except if the
# ident is "and"
if (name == 'IDENT' and
found.lower() != "and" and
match.end(0) < len(text) and
text[match.end(0)] == '('):
continue
if fullsheet:
# check if found may be completed into a full token
if ('INVALID' == name and
suffix_eq(text, pos, found)):
# complete INVALID to STRING with start char " or '
name, found = 'STRING', '%s%s' % (found, found[0])
elif 'FUNCTION' == name and\
'url(' == _normalize(found):
# url( is a FUNCTION if incomplete sheet
# FUNCTION production MUST BE after URI production
for end in ("')", '")', ')'):
possibleuri = '%s%s' % (text[pos:], end)
match = self.urimatcher(possibleuri)
if match:
name, found = 'URI', match.group(0)
break
if name in ('DIMENSION', 'IDENT', 'STRING', 'URI',
'HASH', 'COMMENT', 'FUNCTION', 'INVALID',
'UNICODE-RANGE'):
# may contain unicode escape, replace with normal
# char but do not _normalize (?)
value = self.unicodesub(_repl, found)
if name in ('STRING', 'INVALID'): #'URI'?
# remove \ followed by nl (so escaped) from string
value = self.cleanstring('', value)
else:
if 'ATKEYWORD' == name:
try:
# get actual ATKEYWORD SYM
name = self._atkeywords[_normalize(found)]
except KeyError as e:
# might also be misplace @charset...
if ('@charset' == found and
has_at(text, pos + len(found), ' ')):
# @charset needs tailing S!
name = CSSProductions.CHARSET_SYM
found += ' '
else:
name = 'ATKEYWORD'
value = found # should not contain unicode escape (?)
if self._doComments or (not self._doComments and
name != 'COMMENT'):
yield (name, value, line, col)
pos += len(found)
nls = found.count(self._linesep)
line += nls
if nls:
col = len(found[found.rfind(self._linesep):])
else:
col += len(found)
break
# Make sure we didn't accidentally modify text in the process
assert text is _orig_text
if fullsheet:
yield ('EOF', '', line, col)
def has_at(text, pos, string):
"""Check if text has substring string as position pos.
This is effectively equal to ``text[pos:pos+len(string)] == string``.
If ``pos`` is 0, this is equal to ``text.startswith(string)``.
:param str text: The text to check against.
:param int pos: The starting position where the substring should be
searched.
:param str string: The string to search.
"""
return text[pos:pos+len(string)] == string
def suffix_eq(text, pos, expected):
"""Check if the suffix of text starting at pos equals expected.
This is effectively equivalent to ``text[pos:] == expected``, but avoids
allocating a huge substring.
If ``pos`` is 0, this is equal to ``text == expected``.
:param str text: Text to compare.
:param int pos: Starting position for the suffix.
:param str expected: String to compare to.
"""
if not pos:
return text == expected
return (len(text) - pos == len(expected) and
all(text[i + pos] == expected[i] for i in range(len(expected))))
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