| # -*- 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 not lo and hi: |
| 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 |
| ) |
