mirror of
https://github.com/python/cpython.git
synced 2025-11-04 11:49:12 +00:00
66dc4648fc
for patterns that starts with capturing groups. Fast searching optimization now can't be disabled at compile time.
573 lines
18 KiB
Python
573 lines
18 KiB
Python
#
|
||
# 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
|
||
import sre_parse
|
||
from sre_constants import *
|
||
|
||
assert _sre.MAGIC == MAGIC, "SRE module mismatch"
|
||
|
||
_LITERAL_CODES = {LITERAL, NOT_LITERAL}
|
||
_REPEATING_CODES = {REPEAT, MIN_REPEAT, MAX_REPEAT}
|
||
_SUCCESS_CODES = {SUCCESS, FAILURE}
|
||
_ASSERT_CODES = {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 IOTA WITH DIALYTIKA AND TONOS, GREEK SMALL LETTER IOTA WITH DIALYTIKA AND OXIA
|
||
(0x390, 0x1fd3), # ΐΐ
|
||
# GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND TONOS, GREEK SMALL LETTER UPSILON WITH DIALYTIKA AND OXIA
|
||
(0x3b0, 0x1fe3), # ΰΰ
|
||
# 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
|
||
# LATIN SMALL LIGATURE LONG S T, LATIN SMALL LIGATURE ST
|
||
(0xfb05, 0xfb06), # ſtst
|
||
)
|
||
|
||
# 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(IN_IGNORE)
|
||
skip = _len(code); emit(0)
|
||
if op is NOT_LITERAL:
|
||
emit(NEGATE)
|
||
for k in (lo,) + fixes[lo]:
|
||
emit(LITERAL)
|
||
emit(k)
|
||
emit(FAILURE)
|
||
code[skip] = _len(code) - skip
|
||
else:
|
||
emit(OP_IGNORE[op])
|
||
emit(lo)
|
||
else:
|
||
emit(op)
|
||
emit(av)
|
||
elif op is IN:
|
||
if flags & SRE_FLAG_IGNORECASE:
|
||
emit(OP_IGNORE[op])
|
||
def fixup(literal, flags=flags):
|
||
return _sre.getlower(literal, flags)
|
||
else:
|
||
emit(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(ANY_ALL)
|
||
else:
|
||
emit(ANY)
|
||
elif op in REPEATING_CODES:
|
||
if flags & SRE_FLAG_TEMPLATE:
|
||
raise error("internal: unsupported template operator %r" % (op,))
|
||
elif _simple(av) and op is not REPEAT:
|
||
if op is MAX_REPEAT:
|
||
emit(REPEAT_ONE)
|
||
else:
|
||
emit(MIN_REPEAT_ONE)
|
||
skip = _len(code); emit(0)
|
||
emit(av[0])
|
||
emit(av[1])
|
||
_compile(code, av[2], flags)
|
||
emit(SUCCESS)
|
||
code[skip] = _len(code) - skip
|
||
else:
|
||
emit(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(MAX_UNTIL)
|
||
else:
|
||
emit(MIN_UNTIL)
|
||
elif op is SUBPATTERN:
|
||
if av[0]:
|
||
emit(MARK)
|
||
emit((av[0]-1)*2)
|
||
# _compile_info(code, av[1], flags)
|
||
_compile(code, av[1], flags)
|
||
if av[0]:
|
||
emit(MARK)
|
||
emit((av[0]-1)*2+1)
|
||
elif op in SUCCESS_CODES:
|
||
emit(op)
|
||
elif op in ASSERT_CODES:
|
||
emit(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(SUCCESS)
|
||
code[skip] = _len(code) - skip
|
||
elif op is CALL:
|
||
emit(op)
|
||
skip = _len(code); emit(0)
|
||
_compile(code, av, flags)
|
||
emit(SUCCESS)
|
||
code[skip] = _len(code) - skip
|
||
elif op is AT:
|
||
emit(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(av)
|
||
elif op is BRANCH:
|
||
emit(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(JUMP)
|
||
tailappend(_len(code)); emit(0)
|
||
code[skip] = _len(code) - skip
|
||
emit(FAILURE) # end of branch
|
||
for tail in tail:
|
||
code[tail] = _len(code) - tail
|
||
elif op is CATEGORY:
|
||
emit(op)
|
||
if flags & SRE_FLAG_LOCALE:
|
||
av = CH_LOCALE[av]
|
||
elif flags & SRE_FLAG_UNICODE:
|
||
av = CH_UNICODE[av]
|
||
emit(av)
|
||
elif op is GROUPREF:
|
||
if flags & SRE_FLAG_IGNORECASE:
|
||
emit(OP_IGNORE[op])
|
||
else:
|
||
emit(op)
|
||
emit(av-1)
|
||
elif op is GROUPREF_EXISTS:
|
||
emit(op)
|
||
emit(av[0]-1)
|
||
skipyes = _len(code); emit(0)
|
||
_compile(code, av[1], flags)
|
||
if av[2]:
|
||
emit(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 error("internal: unsupported operand type %r" % (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):
|
||
emit(op)
|
||
if op is NEGATE:
|
||
pass
|
||
elif op is LITERAL:
|
||
emit(av)
|
||
elif op is RANGE or op is RANGE_IGNORE:
|
||
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(CH_LOCALE[av])
|
||
elif flags & SRE_FLAG_UNICODE:
|
||
emit(CH_UNICODE[av])
|
||
else:
|
||
emit(av)
|
||
else:
|
||
raise error("internal: unsupported set operator %r" % (op,))
|
||
emit(FAILURE)
|
||
|
||
def _optimize_charset(charset, fixup, fixes):
|
||
# internal: optimize character set
|
||
out = []
|
||
tail = []
|
||
charmap = bytearray(256)
|
||
for op, av in charset:
|
||
while True:
|
||
try:
|
||
if op is LITERAL:
|
||
if fixup:
|
||
lo = fixup(av)
|
||
charmap[lo] = 1
|
||
if fixes and lo in fixes:
|
||
for k in fixes[lo]:
|
||
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.
|
||
# There are only two ranges of cased non-BMP characters:
|
||
# 10400-1044F (Deseret) and 118A0-118DF (Warang Citi),
|
||
# and for both ranges RANGE_IGNORE works.
|
||
if fixup and op is RANGE:
|
||
op = RANGE_IGNORE
|
||
tail.append((op, av))
|
||
break
|
||
|
||
# compress character map
|
||
runs = []
|
||
q = 0
|
||
while True:
|
||
p = charmap.find(1, q)
|
||
if p < 0:
|
||
break
|
||
if len(runs) >= 2:
|
||
runs = None
|
||
break
|
||
q = charmap.find(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).
|
||
|
||
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
|
||
|
||
_CODEBITS = _sre.CODESIZE * 8
|
||
MAXCODE = (1 << _CODEBITS) - 1
|
||
_BITS_TRANS = b'0' + b'1' * 255
|
||
def _mk_bitmap(bits, _CODEBITS=_CODEBITS, _int=int):
|
||
s = 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
|
||
a = memoryview(b).cast('I')
|
||
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 _generate_overlap_table(prefix):
|
||
"""
|
||
Generate an overlap table for the following prefix.
|
||
An overlap table is a table of the same size as the prefix which
|
||
informs about the potential self-overlap for each index in the prefix:
|
||
- if overlap[i] == 0, prefix[i:] can't overlap prefix[0:...]
|
||
- if overlap[i] == k with 0 < k <= i, prefix[i-k+1:i+1] overlaps with
|
||
prefix[0:k]
|
||
"""
|
||
table = [0] * len(prefix)
|
||
for i in range(1, len(prefix)):
|
||
idx = table[i - 1]
|
||
while prefix[i] != prefix[idx]:
|
||
if idx == 0:
|
||
table[i] = 0
|
||
break
|
||
idx = table[idx - 1]
|
||
else:
|
||
table[i] = idx + 1
|
||
return table
|
||
|
||
def _get_literal_prefix(pattern):
|
||
# look for literal prefix
|
||
prefix = []
|
||
prefixappend = prefix.append
|
||
prefix_skip = None
|
||
got_all = True
|
||
for op, av in pattern.data:
|
||
if op is LITERAL:
|
||
prefixappend(av)
|
||
elif op is SUBPATTERN:
|
||
prefix1, prefix_skip1, got_all = _get_literal_prefix(av[1])
|
||
if prefix_skip is None:
|
||
if av[0] is not None:
|
||
prefix_skip = len(prefix)
|
||
elif prefix_skip1 is not None:
|
||
prefix_skip = len(prefix) + prefix_skip1
|
||
prefix.extend(prefix1)
|
||
if not got_all:
|
||
break
|
||
else:
|
||
got_all = False
|
||
break
|
||
return prefix, prefix_skip, got_all
|
||
|
||
def _get_charset_prefix(pattern):
|
||
charset = [] # not used
|
||
charsetappend = charset.append
|
||
if 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
|
||
return charset
|
||
|
||
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 hi > MAXCODE:
|
||
hi = MAXCODE
|
||
if lo == 0:
|
||
code.extend([INFO, 4, 0, lo, hi])
|
||
return
|
||
# look for a literal prefix
|
||
prefix = []
|
||
prefix_skip = 0
|
||
charset = [] # not used
|
||
if not (flags & SRE_FLAG_IGNORECASE):
|
||
# look for literal prefix
|
||
prefix, prefix_skip, got_all = _get_literal_prefix(pattern)
|
||
# if no prefix, look for charset prefix
|
||
if not prefix:
|
||
charset = _get_charset_prefix(pattern)
|
||
## if prefix:
|
||
## print("*** PREFIX", prefix, prefix_skip)
|
||
## if charset:
|
||
## print("*** CHARSET", charset)
|
||
# add an info block
|
||
emit = code.append
|
||
emit(INFO)
|
||
skip = len(code); emit(0)
|
||
# literal flag
|
||
mask = 0
|
||
if prefix:
|
||
mask = SRE_INFO_PREFIX
|
||
if prefix_skip is None and got_all:
|
||
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]
|
||
emit(min(hi, MAXCODE))
|
||
# add literal prefix
|
||
if prefix:
|
||
emit(len(prefix)) # length
|
||
if prefix_skip is None:
|
||
prefix_skip = len(prefix)
|
||
emit(prefix_skip) # skip
|
||
code.extend(prefix)
|
||
# generate overlap table
|
||
code.extend(_generate_overlap_table(prefix))
|
||
elif charset:
|
||
_compile_charset(charset, flags, code)
|
||
code[skip] = len(code) - skip
|
||
|
||
def isstring(obj):
|
||
return isinstance(obj, (str, bytes))
|
||
|
||
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(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)
|
||
|
||
# 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
|
||
)
|