# -*- 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 | |
) |