mirror of
https://github.com/python/cpython.git
synced 2025-07-16 07:45:20 +00:00
0640e1161f
-- added pickling support (only works if sre is imported) -- fixed wordsize problems in engine (instead of casting literals down to the character size, cast characters up to the literal size (same as the code word size). this prevents false hits when you're matching a unicode pattern against an 8-bit string. (unfortunately, this broke another test, but I think the test should be changed in this case; more on that on python-dev) -- added sre.purge function (unofficial, clears the cache)
157 lines
4 KiB
Python
157 lines
4 KiB
Python
#
|
|
# Secret Labs' Regular Expression Engine
|
|
#
|
|
# re-compatible interface for the sre matching engine
|
|
#
|
|
# Copyright (c) 1998-2000 by Secret Labs AB. All rights reserved.
|
|
#
|
|
# Portions of this engine have been developed in cooperation with
|
|
# CNRI. Hewlett-Packard provided funding for 1.6 integration and
|
|
# other compatibility work.
|
|
#
|
|
|
|
import sre_compile
|
|
import sre_parse
|
|
|
|
# flags
|
|
I = IGNORECASE = sre_compile.SRE_FLAG_IGNORECASE
|
|
L = LOCALE = sre_compile.SRE_FLAG_LOCALE
|
|
M = MULTILINE = sre_compile.SRE_FLAG_MULTILINE
|
|
S = DOTALL = sre_compile.SRE_FLAG_DOTALL
|
|
X = VERBOSE = sre_compile.SRE_FLAG_VERBOSE
|
|
|
|
# sre extensions (may or may not be in 2.0 final)
|
|
T = TEMPLATE = sre_compile.SRE_FLAG_TEMPLATE
|
|
U = UNICODE = sre_compile.SRE_FLAG_UNICODE
|
|
|
|
# sre exception
|
|
error = sre_compile.error
|
|
|
|
# --------------------------------------------------------------------
|
|
# public interface
|
|
|
|
# FIXME: add docstrings
|
|
|
|
def match(pattern, string, flags=0):
|
|
return _compile(pattern, flags).match(string)
|
|
|
|
def search(pattern, string, flags=0):
|
|
return _compile(pattern, flags).search(string)
|
|
|
|
def sub(pattern, repl, string, count=0):
|
|
return _compile(pattern).sub(repl, string, count)
|
|
|
|
def subn(pattern, repl, string, count=0):
|
|
return _compile(pattern).subn(repl, string, count)
|
|
|
|
def split(pattern, string, maxsplit=0):
|
|
return _compile(pattern).split(string, maxsplit)
|
|
|
|
def findall(pattern, string, maxsplit=0):
|
|
return _compile(pattern).findall(string, maxsplit)
|
|
|
|
def compile(pattern, flags=0):
|
|
return _compile(pattern, flags)
|
|
|
|
def template(pattern, flags=0):
|
|
return _compile(pattern, flags|T)
|
|
|
|
def escape(pattern):
|
|
s = list(pattern)
|
|
for i in range(len(pattern)):
|
|
c = pattern[i]
|
|
if not ("a" <= c <= "z" or "A" <= c <= "Z" or "0" <= c <= "9"):
|
|
if c == "\000":
|
|
s[i] = "\\000"
|
|
else:
|
|
s[i] = "\\" + c
|
|
return pattern[:0].join(s)
|
|
|
|
# --------------------------------------------------------------------
|
|
# internals
|
|
|
|
_cache = {}
|
|
_MAXCACHE = 100
|
|
|
|
def _compile(pattern, flags=0):
|
|
# internal: compile pattern
|
|
tp = type(pattern)
|
|
if tp not in (type(""), type(u"")):
|
|
return pattern
|
|
key = (tp, pattern, flags)
|
|
try:
|
|
return _cache[key]
|
|
except KeyError:
|
|
pass
|
|
p = sre_compile.compile(pattern, flags)
|
|
if len(_cache) >= _MAXCACHE:
|
|
_cache.clear()
|
|
_cache[key] = p
|
|
return p
|
|
|
|
def purge():
|
|
# clear pattern cache
|
|
_cache.clear()
|
|
|
|
def _sub(pattern, template, string, count=0):
|
|
# internal: pattern.sub implementation hook
|
|
return _subn(pattern, template, string, count)[0]
|
|
|
|
def _subn(pattern, template, string, count=0):
|
|
# internal: pattern.subn implementation hook
|
|
if callable(template):
|
|
filter = template
|
|
else:
|
|
template = sre_parse.parse_template(template, pattern)
|
|
def filter(match, template=template):
|
|
return sre_parse.expand_template(template, match)
|
|
n = i = 0
|
|
s = []
|
|
append = s.append
|
|
c = pattern.scanner(string)
|
|
while not count or n < count:
|
|
m = c.search()
|
|
if not m:
|
|
break
|
|
b, e = m.span()
|
|
if i < b:
|
|
append(string[i:b])
|
|
append(filter(m))
|
|
i = e
|
|
n = n + 1
|
|
append(string[i:])
|
|
return string[:0].join(s), n
|
|
|
|
def _split(pattern, string, maxsplit=0):
|
|
# internal: pattern.split implementation hook
|
|
n = i = 0
|
|
s = []
|
|
append = s.append
|
|
extend = s.extend
|
|
c = pattern.scanner(string)
|
|
g = pattern.groups
|
|
while not maxsplit or n < maxsplit:
|
|
m = c.search()
|
|
if not m:
|
|
break
|
|
b, e = m.span()
|
|
if b == e:
|
|
if i >= len(string):
|
|
break
|
|
continue
|
|
append(string[i:b])
|
|
if g and b != e:
|
|
extend(m.groups())
|
|
i = e
|
|
n = n + 1
|
|
append(string[i:])
|
|
return s
|
|
|
|
# register myself for pickling
|
|
|
|
import copy_reg
|
|
|
|
def _pickle(p):
|
|
return _compile, (p.pattern, p.flags)
|
|
|
|
copy_reg.pickle(type(_compile("")), _pickle, _compile)
|