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- # -*- coding: utf-8 -*-
- #
- # Secret Labs' Regular Expression Engine
- #
- # convert template to internal format
- #
- # Copyright (c) 1997-2001 by Secret Labs AB. All rights reserved.
- #
- # See the sre.py file for information on usage and redistribution.
- #
- """Internal support module for sre"""
- import _sre, sys
- import sre_parse
- from sre_constants import *
- assert _sre.MAGIC == MAGIC, "SRE module mismatch"
- if _sre.CODESIZE == 2:
- MAXCODE = 65535
- else:
- MAXCODE = 0xFFFFFFFFL
- _LITERAL_CODES = set([LITERAL, NOT_LITERAL])
- _REPEATING_CODES = set([REPEAT, MIN_REPEAT, MAX_REPEAT])
- _SUCCESS_CODES = set([SUCCESS, FAILURE])
- _ASSERT_CODES = set([ASSERT, ASSERT_NOT])
- # Sets of lowercase characters which have the same uppercase.
- _equivalences = (
- # LATIN SMALL LETTER I, LATIN SMALL LETTER DOTLESS I
- (0x69, 0x131), # iı
- # LATIN SMALL LETTER S, LATIN SMALL LETTER LONG S
- (0x73, 0x17f), # sſ
- # MICRO SIGN, GREEK SMALL LETTER MU
- (0xb5, 0x3bc), # µμ
- # COMBINING GREEK YPOGEGRAMMENI, GREEK SMALL LETTER IOTA, GREEK PROSGEGRAMMENI
- (0x345, 0x3b9, 0x1fbe), # \u0345ιι
- # GREEK SMALL LETTER BETA, GREEK BETA SYMBOL
- (0x3b2, 0x3d0), # βϐ
- # GREEK SMALL LETTER EPSILON, GREEK LUNATE EPSILON SYMBOL
- (0x3b5, 0x3f5), # εϵ
- # GREEK SMALL LETTER THETA, GREEK THETA SYMBOL
- (0x3b8, 0x3d1), # θϑ
- # GREEK SMALL LETTER KAPPA, GREEK KAPPA SYMBOL
- (0x3ba, 0x3f0), # κϰ
- # GREEK SMALL LETTER PI, GREEK PI SYMBOL
- (0x3c0, 0x3d6), # πϖ
- # GREEK SMALL LETTER RHO, GREEK RHO SYMBOL
- (0x3c1, 0x3f1), # ρϱ
- # GREEK SMALL LETTER FINAL SIGMA, GREEK SMALL LETTER SIGMA
- (0x3c2, 0x3c3), # ςσ
- # GREEK SMALL LETTER PHI, GREEK PHI SYMBOL
- (0x3c6, 0x3d5), # φϕ
- # LATIN SMALL LETTER S WITH DOT ABOVE, LATIN SMALL LETTER LONG S WITH DOT ABOVE
- (0x1e61, 0x1e9b), # ṡẛ
- )
- # Maps the lowercase code to lowercase codes which have the same uppercase.
- _ignorecase_fixes = {i: tuple(j for j in t if i != j)
- for t in _equivalences for i in t}
- def _compile(code, pattern, flags):
- # internal: compile a (sub)pattern
- emit = code.append
- _len = len
- LITERAL_CODES = _LITERAL_CODES
- REPEATING_CODES = _REPEATING_CODES
- SUCCESS_CODES = _SUCCESS_CODES
- ASSERT_CODES = _ASSERT_CODES
- if (flags & SRE_FLAG_IGNORECASE and
- not (flags & SRE_FLAG_LOCALE) and
- flags & SRE_FLAG_UNICODE):
- fixes = _ignorecase_fixes
- else:
- fixes = None
- for op, av in pattern:
- if op in LITERAL_CODES:
- if flags & SRE_FLAG_IGNORECASE:
- lo = _sre.getlower(av, flags)
- if fixes and lo in fixes:
- emit(OPCODES[IN_IGNORE])
- skip = _len(code); emit(0)
- if op is NOT_LITERAL:
- emit(OPCODES[NEGATE])
- for k in (lo,) + fixes[lo]:
- emit(OPCODES[LITERAL])
- emit(k)
- emit(OPCODES[FAILURE])
- code[skip] = _len(code) - skip
- else:
- emit(OPCODES[OP_IGNORE[op]])
- emit(lo)
- else:
- emit(OPCODES[op])
- emit(av)
- elif op is IN:
- if flags & SRE_FLAG_IGNORECASE:
- emit(OPCODES[OP_IGNORE[op]])
- def fixup(literal, flags=flags):
- return _sre.getlower(literal, flags)
- else:
- emit(OPCODES[op])
- fixup = None
- skip = _len(code); emit(0)
- _compile_charset(av, flags, code, fixup, fixes)
- code[skip] = _len(code) - skip
- elif op is ANY:
- if flags & SRE_FLAG_DOTALL:
- emit(OPCODES[ANY_ALL])
- else:
- emit(OPCODES[ANY])
- elif op in REPEATING_CODES:
- if flags & SRE_FLAG_TEMPLATE:
- raise error, "internal: unsupported template operator"
- emit(OPCODES[REPEAT])
- skip = _len(code); emit(0)
- emit(av[0])
- emit(av[1])
- _compile(code, av[2], flags)
- emit(OPCODES[SUCCESS])
- code[skip] = _len(code) - skip
- elif _simple(av) and op is not REPEAT:
- if op is MAX_REPEAT:
- emit(OPCODES[REPEAT_ONE])
- else:
- emit(OPCODES[MIN_REPEAT_ONE])
- skip = _len(code); emit(0)
- emit(av[0])
- emit(av[1])
- _compile(code, av[2], flags)
- emit(OPCODES[SUCCESS])
- code[skip] = _len(code) - skip
- else:
- emit(OPCODES[REPEAT])
- skip = _len(code); emit(0)
- emit(av[0])
- emit(av[1])
- _compile(code, av[2], flags)
- code[skip] = _len(code) - skip
- if op is MAX_REPEAT:
- emit(OPCODES[MAX_UNTIL])
- else:
- emit(OPCODES[MIN_UNTIL])
- elif op is SUBPATTERN:
- if av[0]:
- emit(OPCODES[MARK])
- emit((av[0]-1)*2)
- # _compile_info(code, av[1], flags)
- _compile(code, av[1], flags)
- if av[0]:
- emit(OPCODES[MARK])
- emit((av[0]-1)*2+1)
- elif op in SUCCESS_CODES:
- emit(OPCODES[op])
- elif op in ASSERT_CODES:
- emit(OPCODES[op])
- skip = _len(code); emit(0)
- if av[0] >= 0:
- emit(0) # look ahead
- else:
- lo, hi = av[1].getwidth()
- if lo != hi:
- raise error, "look-behind requires fixed-width pattern"
- emit(lo) # look behind
- _compile(code, av[1], flags)
- emit(OPCODES[SUCCESS])
- code[skip] = _len(code) - skip
- elif op is CALL:
- emit(OPCODES[op])
- skip = _len(code); emit(0)
- _compile(code, av, flags)
- emit(OPCODES[SUCCESS])
- code[skip] = _len(code) - skip
- elif op is AT:
- emit(OPCODES[op])
- if flags & SRE_FLAG_MULTILINE:
- av = AT_MULTILINE.get(av, av)
- if flags & SRE_FLAG_LOCALE:
- av = AT_LOCALE.get(av, av)
- elif flags & SRE_FLAG_UNICODE:
- av = AT_UNICODE.get(av, av)
- emit(ATCODES[av])
- elif op is BRANCH:
- emit(OPCODES[op])
- tail = []
- tailappend = tail.append
- for av in av[1]:
- skip = _len(code); emit(0)
- # _compile_info(code, av, flags)
- _compile(code, av, flags)
- emit(OPCODES[JUMP])
- tailappend(_len(code)); emit(0)
- code[skip] = _len(code) - skip
- emit(0) # end of branch
- for tail in tail:
- code[tail] = _len(code) - tail
- elif op is CATEGORY:
- emit(OPCODES[op])
- if flags & SRE_FLAG_LOCALE:
- av = CH_LOCALE[av]
- elif flags & SRE_FLAG_UNICODE:
- av = CH_UNICODE[av]
- emit(CHCODES[av])
- elif op is GROUPREF:
- if flags & SRE_FLAG_IGNORECASE:
- emit(OPCODES[OP_IGNORE[op]])
- else:
- emit(OPCODES[op])
- emit(av-1)
- elif op is GROUPREF_EXISTS:
- emit(OPCODES[op])
- emit(av[0]-1)
- skipyes = _len(code); emit(0)
- _compile(code, av[1], flags)
- if av[2]:
- emit(OPCODES[JUMP])
- skipno = _len(code); emit(0)
- code[skipyes] = _len(code) - skipyes + 1
- _compile(code, av[2], flags)
- code[skipno] = _len(code) - skipno
- else:
- code[skipyes] = _len(code) - skipyes + 1
- else:
- raise ValueError, ("unsupported operand type", op)
- def _compile_charset(charset, flags, code, fixup=None, fixes=None):
- # compile charset subprogram
- emit = code.append
- for op, av in _optimize_charset(charset, fixup, fixes,
- flags & SRE_FLAG_UNICODE):
- emit(OPCODES[op])
- if op is NEGATE:
- pass
- elif op is LITERAL:
- emit(av)
- elif op is RANGE:
- emit(av[0])
- emit(av[1])
- elif op is CHARSET:
- code.extend(av)
- elif op is BIGCHARSET:
- code.extend(av)
- elif op is CATEGORY:
- if flags & SRE_FLAG_LOCALE:
- emit(CHCODES[CH_LOCALE[av]])
- elif flags & SRE_FLAG_UNICODE:
- emit(CHCODES[CH_UNICODE[av]])
- else:
- emit(CHCODES[av])
- else:
- raise error, "internal: unsupported set operator"
- emit(OPCODES[FAILURE])
- def _optimize_charset(charset, fixup, fixes, isunicode):
- # internal: optimize character set
- out = []
- tail = []
- charmap = bytearray(256)
- for op, av in charset:
- while True:
- try:
- if op is LITERAL:
- if fixup:
- i = fixup(av)
- charmap[i] = 1
- if fixes and i in fixes:
- for k in fixes[i]:
- charmap[k] = 1
- else:
- charmap[av] = 1
- elif op is RANGE:
- r = range(av[0], av[1]+1)
- if fixup:
- r = map(fixup, r)
- if fixup and fixes:
- for i in r:
- charmap[i] = 1
- if i in fixes:
- for k in fixes[i]:
- charmap[k] = 1
- else:
- for i in r:
- charmap[i] = 1
- elif op is NEGATE:
- out.append((op, av))
- else:
- tail.append((op, av))
- except IndexError:
- if len(charmap) == 256:
- # character set contains non-UCS1 character codes
- charmap += b'\0' * 0xff00
- continue
- # character set contains non-BMP character codes
- if fixup and isunicode and op is RANGE:
- lo, hi = av
- ranges = [av]
- # There are only two ranges of cased astral characters:
- # 10400-1044F (Deseret) and 118A0-118DF (Warang Citi).
- _fixup_range(max(0x10000, lo), min(0x11fff, hi),
- ranges, fixup)
- for lo, hi in ranges:
- if lo == hi:
- tail.append((LITERAL, hi))
- else:
- tail.append((RANGE, (lo, hi)))
- else:
- tail.append((op, av))
- break
- # compress character map
- runs = []
- q = 0
- while True:
- p = charmap.find(b'\1', q)
- if p < 0:
- break
- if len(runs) >= 2:
- runs = None
- break
- q = charmap.find(b'\0', p)
- if q < 0:
- runs.append((p, len(charmap)))
- break
- runs.append((p, q))
- if runs is not None:
- # use literal/range
- for p, q in runs:
- if q - p == 1:
- out.append((LITERAL, p))
- else:
- out.append((RANGE, (p, q - 1)))
- out += tail
- # if the case was changed or new representation is more compact
- if fixup or len(out) < len(charset):
- return out
- # else original character set is good enough
- return charset
- # use bitmap
- if len(charmap) == 256:
- data = _mk_bitmap(charmap)
- out.append((CHARSET, data))
- out += tail
- return out
- # To represent a big charset, first a bitmap of all characters in the
- # set is constructed. Then, this bitmap is sliced into chunks of 256
- # characters, duplicate chunks are eliminated, and each chunk is
- # given a number. In the compiled expression, the charset is
- # represented by a 32-bit word sequence, consisting of one word for
- # the number of different chunks, a sequence of 256 bytes (64 words)
- # of chunk numbers indexed by their original chunk position, and a
- # sequence of 256-bit chunks (8 words each).
- # Compression is normally good: in a typical charset, large ranges of
- # Unicode will be either completely excluded (e.g. if only cyrillic
- # letters are to be matched), or completely included (e.g. if large
- # subranges of Kanji match). These ranges will be represented by
- # chunks of all one-bits or all zero-bits.
- # Matching can be also done efficiently: the more significant byte of
- # the Unicode character is an index into the chunk number, and the
- # less significant byte is a bit index in the chunk (just like the
- # CHARSET matching).
- # In UCS-4 mode, the BIGCHARSET opcode still supports only subsets
- # of the basic multilingual plane; an efficient representation
- # for all of Unicode has not yet been developed.
- charmap = bytes(charmap) # should be hashable
- comps = {}
- mapping = bytearray(256)
- block = 0
- data = bytearray()
- for i in range(0, 65536, 256):
- chunk = charmap[i: i + 256]
- if chunk in comps:
- mapping[i // 256] = comps[chunk]
- else:
- mapping[i // 256] = comps[chunk] = block
- block += 1
- data += chunk
- data = _mk_bitmap(data)
- data[0:0] = [block] + _bytes_to_codes(mapping)
- out.append((BIGCHARSET, data))
- out += tail
- return out
- def _fixup_range(lo, hi, ranges, fixup):
- for i in map(fixup, range(lo, hi+1)):
- for k, (lo, hi) in enumerate(ranges):
- if i < lo:
- if l == lo - 1:
- ranges[k] = (i, hi)
- else:
- ranges.insert(k, (i, i))
- break
- elif i > hi:
- if i == hi + 1:
- ranges[k] = (lo, i)
- break
- else:
- break
- else:
- ranges.append((i, i))
- _CODEBITS = _sre.CODESIZE * 8
- _BITS_TRANS = b'0' + b'1' * 255
- def _mk_bitmap(bits, _CODEBITS=_CODEBITS, _int=int):
- s = bytes(bits).translate(_BITS_TRANS)[::-1]
- return [_int(s[i - _CODEBITS: i], 2)
- for i in range(len(s), 0, -_CODEBITS)]
- def _bytes_to_codes(b):
- # Convert block indices to word array
- import array
- if _sre.CODESIZE == 2:
- code = 'H'
- else:
- code = 'I'
- a = array.array(code, bytes(b))
- assert a.itemsize == _sre.CODESIZE
- assert len(a) * a.itemsize == len(b)
- return a.tolist()
- def _simple(av):
- # check if av is a "simple" operator
- lo, hi = av[2].getwidth()
- return lo == hi == 1 and av[2][0][0] != SUBPATTERN
- def _compile_info(code, pattern, flags):
- # internal: compile an info block. in the current version,
- # this contains min/max pattern width, and an optional literal
- # prefix or a character map
- lo, hi = pattern.getwidth()
- if lo == 0:
- return # not worth it
- # look for a literal prefix
- prefix = []
- prefixappend = prefix.append
- prefix_skip = 0
- charset = [] # not used
- charsetappend = charset.append
- if not (flags & SRE_FLAG_IGNORECASE):
- # look for literal prefix
- for op, av in pattern.data:
- if op is LITERAL:
- if len(prefix) == prefix_skip:
- prefix_skip = prefix_skip + 1
- prefixappend(av)
- elif op is SUBPATTERN and len(av[1]) == 1:
- op, av = av[1][0]
- if op is LITERAL:
- prefixappend(av)
- else:
- break
- else:
- break
- # if no prefix, look for charset prefix
- if not prefix and pattern.data:
- op, av = pattern.data[0]
- if op is SUBPATTERN and av[1]:
- op, av = av[1][0]
- if op is LITERAL:
- charsetappend((op, av))
- elif op is BRANCH:
- c = []
- cappend = c.append
- for p in av[1]:
- if not p:
- break
- op, av = p[0]
- if op is LITERAL:
- cappend((op, av))
- else:
- break
- else:
- charset = c
- elif op is BRANCH:
- c = []
- cappend = c.append
- for p in av[1]:
- if not p:
- break
- op, av = p[0]
- if op is LITERAL:
- cappend((op, av))
- else:
- break
- else:
- charset = c
- elif op is IN:
- charset = av
- ## if prefix:
- ## print "*** PREFIX", prefix, prefix_skip
- ## if charset:
- ## print "*** CHARSET", charset
- # add an info block
- emit = code.append
- emit(OPCODES[INFO])
- skip = len(code); emit(0)
- # literal flag
- mask = 0
- if prefix:
- mask = SRE_INFO_PREFIX
- if len(prefix) == prefix_skip == len(pattern.data):
- mask = mask + SRE_INFO_LITERAL
- elif charset:
- mask = mask + SRE_INFO_CHARSET
- emit(mask)
- # pattern length
- if lo < MAXCODE:
- emit(lo)
- else:
- emit(MAXCODE)
- prefix = prefix[:MAXCODE]
- if hi < MAXCODE:
- emit(hi)
- else:
- emit(0)
- # add literal prefix
- if prefix:
- emit(len(prefix)) # length
- emit(prefix_skip) # skip
- code.extend(prefix)
- # generate overlap table
- table = [-1] + ([0]*len(prefix))
- for i in xrange(len(prefix)):
- table[i+1] = table[i]+1
- while table[i+1] > 0 and prefix[i] != prefix[table[i+1]-1]:
- table[i+1] = table[table[i+1]-1]+1
- code.extend(table[1:]) # don't store first entry
- elif charset:
- _compile_charset(charset, flags, code)
- code[skip] = len(code) - skip
- try:
- unicode
- except NameError:
- STRING_TYPES = (type(""),)
- else:
- STRING_TYPES = (type(""), type(unicode("")))
- def isstring(obj):
- for tp in STRING_TYPES:
- if isinstance(obj, tp):
- return 1
- return 0
- def _code(p, flags):
- flags = p.pattern.flags | flags
- code = []
- # compile info block
- _compile_info(code, p, flags)
- # compile the pattern
- _compile(code, p.data, flags)
- code.append(OPCODES[SUCCESS])
- return code
- def compile(p, flags=0):
- # internal: convert pattern list to internal format
- if isstring(p):
- pattern = p
- p = sre_parse.parse(p, flags)
- else:
- pattern = None
- code = _code(p, flags)
- # print code
- # XXX: <fl> get rid of this limitation!
- if p.pattern.groups > 100:
- raise AssertionError(
- "sorry, but this version only supports 100 named groups"
- )
- # map in either direction
- groupindex = p.pattern.groupdict
- indexgroup = [None] * p.pattern.groups
- for k, i in groupindex.items():
- indexgroup[i] = k
- return _sre.compile(
- pattern, flags | p.pattern.flags, code,
- p.pattern.groups-1,
- groupindex, indexgroup
- )
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