mirror of
https://github.com/python/cpython.git
synced 2024-11-24 10:24:35 +08:00
Patch from /F: this patch brings the CVS version of SRE in sync with the
latest public snapshot.""
This commit is contained in:
Andrew M. Kuchling
parent
cb95a1470a
commit
815d5b934b
298
Lib/sre_parse.py
298
Lib/sre_parse.py
@ -2,9 +2,7 @@
|
||||
# Secret Labs' Regular Expression Engine
|
||||
# $Id$
|
||||
#
|
||||
# convert re-style regular expression to SRE template. the current
|
||||
# implementation is somewhat incomplete, and not very fast. should
|
||||
# definitely be rewritten before Python 1.6 goes beta.
|
||||
# convert re-style regular expression to sre pattern
|
||||
#
|
||||
# Copyright (c) 1998-2000 by Secret Labs AB. All rights reserved.
|
||||
#
|
||||
@ -16,13 +14,16 @@
|
||||
# other compatibility work.
|
||||
#
|
||||
|
||||
# FIXME: comments marked with the FIXME tag are open issues. all such
|
||||
# issues should be closed before the final beta.
|
||||
|
||||
import string, sys
|
||||
|
||||
import _sre
|
||||
|
||||
from sre_constants import *
|
||||
|
||||
# FIXME: should be 65535, but the array module currently chokes on
|
||||
# unsigned integers larger than 32767...
|
||||
MAXREPEAT = int(2L**(_sre.getcodesize()*8-1))-1
|
||||
|
||||
SPECIAL_CHARS = ".\\[{()*+?^$|"
|
||||
REPEAT_CHARS = "*+?{"
|
||||
|
||||
@ -32,6 +33,8 @@ DIGITS = tuple(string.digits)
|
||||
OCTDIGITS = tuple("01234567")
|
||||
HEXDIGITS = tuple("0123456789abcdefABCDEF")
|
||||
|
||||
WHITESPACE = tuple(string.whitespace)
|
||||
|
||||
ESCAPES = {
|
||||
"\\a": (LITERAL, chr(7)),
|
||||
"\\b": (LITERAL, chr(8)),
|
||||
@ -55,10 +58,18 @@ CATEGORIES = {
|
||||
"\\Z": (AT, AT_END), # end of string
|
||||
}
|
||||
|
||||
class Pattern:
|
||||
# FIXME: <fl> rename class, and store flags in here too!
|
||||
FLAGS = {
|
||||
"i": SRE_FLAG_IGNORECASE,
|
||||
"L": SRE_FLAG_LOCALE,
|
||||
"m": SRE_FLAG_MULTILINE,
|
||||
"s": SRE_FLAG_DOTALL,
|
||||
"t": SRE_FLAG_TEMPLATE,
|
||||
"x": SRE_FLAG_VERBOSE,
|
||||
}
|
||||
|
||||
class State:
|
||||
def __init__(self):
|
||||
self.flags = []
|
||||
self.flags = 0
|
||||
self.groups = 1
|
||||
self.groupdict = {}
|
||||
def getgroup(self, name=None):
|
||||
@ -67,9 +78,6 @@ class Pattern:
|
||||
if name:
|
||||
self.groupdict[name] = gid
|
||||
return gid
|
||||
def setflag(self, flag):
|
||||
if flag in self.flags:
|
||||
self.flags.append(flag)
|
||||
|
||||
class SubPattern:
|
||||
# a subpattern, in intermediate form
|
||||
@ -78,7 +86,6 @@ class SubPattern:
|
||||
if not data:
|
||||
data = []
|
||||
self.data = data
|
||||
self.flags = []
|
||||
self.width = None
|
||||
def __repr__(self):
|
||||
return repr(self.data)
|
||||
@ -121,8 +128,8 @@ class SubPattern:
|
||||
hi = hi + j
|
||||
elif op in (MIN_REPEAT, MAX_REPEAT):
|
||||
i, j = av[2].getwidth()
|
||||
lo = lo + i * av[0]
|
||||
hi = hi + j * av[1]
|
||||
lo = lo + long(i) * av[0]
|
||||
hi = hi + long(j) * av[1]
|
||||
elif op in (ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY):
|
||||
lo = lo + 1
|
||||
hi = hi + 1
|
||||
@ -130,47 +137,23 @@ class SubPattern:
|
||||
break
|
||||
self.width = int(min(lo, sys.maxint)), int(min(hi, sys.maxint))
|
||||
return self.width
|
||||
def set(self, flag):
|
||||
if not flag in self.flags:
|
||||
self.flags.append(flag)
|
||||
def reset(self, flag):
|
||||
if flag in self.flags:
|
||||
self.flags.remove(flag)
|
||||
|
||||
class Tokenizer:
|
||||
def __init__(self, string):
|
||||
self.string = list(string)
|
||||
self.index = 0
|
||||
self.string = string
|
||||
self.next = self.__next()
|
||||
def __next(self):
|
||||
if not self.string:
|
||||
if self.index >= len(self.string):
|
||||
return None
|
||||
char = self.string[0]
|
||||
char = self.string[self.index]
|
||||
if char[0] == "\\":
|
||||
try:
|
||||
c = self.string[1]
|
||||
c = self.string[self.index + 1]
|
||||
except IndexError:
|
||||
raise SyntaxError, "bogus escape"
|
||||
char = char + c
|
||||
try:
|
||||
if c == "x":
|
||||
# hexadecimal constant
|
||||
for i in xrange(2, sys.maxint):
|
||||
c = self.string[i]
|
||||
if str(c) not in HEXDIGITS:
|
||||
break
|
||||
char = char + c
|
||||
elif str(c) in DIGITS:
|
||||
# decimal (or octal) number
|
||||
for i in xrange(2, sys.maxint):
|
||||
c = self.string[i]
|
||||
# FIXME: if larger than current number of
|
||||
# groups, interpret as an octal number
|
||||
if str(c) not in DIGITS:
|
||||
break
|
||||
char = char + c
|
||||
except IndexError:
|
||||
pass # use what we've got this far
|
||||
del self.string[0:len(char)]
|
||||
self.index = self.index + len(char)
|
||||
return char
|
||||
def match(self, char):
|
||||
if char == self.next:
|
||||
@ -187,46 +170,87 @@ class Tokenizer:
|
||||
self.next = self.__next()
|
||||
return this
|
||||
|
||||
def _fixescape(escape, character_class=0):
|
||||
# convert escape to (type, value)
|
||||
if character_class:
|
||||
# inside a character class, we'll look in the character
|
||||
# escapes dictionary first
|
||||
code = ESCAPES.get(escape)
|
||||
if code:
|
||||
return code
|
||||
code = CATEGORIES.get(escape)
|
||||
else:
|
||||
code = CATEGORIES.get(escape)
|
||||
if code:
|
||||
return code
|
||||
code = ESCAPES.get(escape)
|
||||
def _group(escape, state):
|
||||
# check if the escape string represents a valid group
|
||||
try:
|
||||
group = int(escape[1:])
|
||||
if group and group < state.groups:
|
||||
return group
|
||||
except ValueError:
|
||||
pass
|
||||
return None # not a valid group
|
||||
|
||||
def _class_escape(source, escape):
|
||||
# handle escape code inside character class
|
||||
code = ESCAPES.get(escape)
|
||||
if code:
|
||||
return code
|
||||
code = CATEGORIES.get(escape)
|
||||
if code:
|
||||
return code
|
||||
if not character_class:
|
||||
try:
|
||||
group = int(escape[1:])
|
||||
# FIXME: only valid if group <= current number of groups
|
||||
return GROUP, group
|
||||
except ValueError:
|
||||
pass
|
||||
try:
|
||||
if escape[1:2] == "x":
|
||||
while source.next in HEXDIGITS:
|
||||
escape = escape + source.get()
|
||||
escape = escape[2:]
|
||||
return LITERAL, chr(int(escape[-2:], 16) & 0xff)
|
||||
elif str(escape[1:2]) in DIGITS:
|
||||
return LITERAL, chr(int(escape[1:], 8) & 0xff)
|
||||
elif len(escape) == 2:
|
||||
# FIXME: support unicode characters!
|
||||
return LITERAL, chr(int(escape[-4:], 16) & 0xff)
|
||||
elif str(escape[1:2]) in OCTDIGITS:
|
||||
while source.next in OCTDIGITS:
|
||||
escape = escape + source.get()
|
||||
escape = escape[1:]
|
||||
# FIXME: support unicode characters!
|
||||
return LITERAL, chr(int(escape[-6:], 8) & 0xff)
|
||||
if len(escape) == 2:
|
||||
return LITERAL, escape[1]
|
||||
except ValueError:
|
||||
pass
|
||||
raise SyntaxError, "bogus escape: %s" % repr(escape)
|
||||
|
||||
def _branch(subpattern, items):
|
||||
def _escape(source, escape, state):
|
||||
# handle escape code in expression
|
||||
code = CATEGORIES.get(escape)
|
||||
if code:
|
||||
return code
|
||||
code = ESCAPES.get(escape)
|
||||
if code:
|
||||
return code
|
||||
try:
|
||||
if escape[1:2] == "x":
|
||||
while source.next in HEXDIGITS:
|
||||
escape = escape + source.get()
|
||||
escape = escape[2:]
|
||||
# FIXME: support unicode characters!
|
||||
return LITERAL, chr(int(escape[-4:], 16) & 0xff)
|
||||
elif str(escape[1:2]) in DIGITS:
|
||||
while 1:
|
||||
group = _group(escape, state)
|
||||
if group:
|
||||
if (not source.next or
|
||||
not _group(escape + source.next, state)):
|
||||
return GROUP, group
|
||||
escape = escape + source.get()
|
||||
elif source.next in OCTDIGITS:
|
||||
escape = escape + source.get()
|
||||
else:
|
||||
break
|
||||
escape = escape[1:]
|
||||
# FIXME: support unicode characters!
|
||||
return LITERAL, chr(int(escape[-6:], 8) & 0xff)
|
||||
if len(escape) == 2:
|
||||
return LITERAL, escape[1]
|
||||
except ValueError:
|
||||
pass
|
||||
raise SyntaxError, "bogus escape: %s" % repr(escape)
|
||||
|
||||
|
||||
def _branch(pattern, items):
|
||||
|
||||
# form a branch operator from a set of items (FIXME: move this
|
||||
# optimization to the compiler module!)
|
||||
|
||||
subpattern = SubPattern(pattern)
|
||||
|
||||
# check if all items share a common prefix
|
||||
while 1:
|
||||
prefix = None
|
||||
@ -257,17 +281,16 @@ def _branch(subpattern, items):
|
||||
for item in items:
|
||||
set.append(item[0])
|
||||
subpattern.append((IN, set))
|
||||
return
|
||||
return subpattern
|
||||
|
||||
subpattern.append((BRANCH, (None, items)))
|
||||
return subpattern
|
||||
|
||||
def _parse(source, pattern, flags=()):
|
||||
def _parse(source, state, flags=0):
|
||||
|
||||
# parse regular expression pattern into an operator list.
|
||||
|
||||
subpattern = SubPattern(pattern)
|
||||
|
||||
this = None
|
||||
subpattern = SubPattern(state)
|
||||
|
||||
while 1:
|
||||
|
||||
@ -277,6 +300,17 @@ def _parse(source, pattern, flags=()):
|
||||
if this is None:
|
||||
break # end of pattern
|
||||
|
||||
if state.flags & SRE_FLAG_VERBOSE:
|
||||
# skip whitespace and comments
|
||||
if this in WHITESPACE:
|
||||
continue
|
||||
if this == "#":
|
||||
while 1:
|
||||
this = source.get()
|
||||
if this in (None, "\n"):
|
||||
break
|
||||
continue
|
||||
|
||||
if this and this[0] not in SPECIAL_CHARS:
|
||||
subpattern.append((LITERAL, this))
|
||||
|
||||
@ -294,7 +328,7 @@ def _parse(source, pattern, flags=()):
|
||||
if this == "]" and set != start:
|
||||
break
|
||||
elif this and this[0] == "\\":
|
||||
code1 = _fixescape(this, 1)
|
||||
code1 = _class_escape(source, this)
|
||||
elif this:
|
||||
code1 = LITERAL, this
|
||||
else:
|
||||
@ -308,7 +342,7 @@ def _parse(source, pattern, flags=()):
|
||||
break
|
||||
else:
|
||||
if this[0] == "\\":
|
||||
code2 = _fixescape(this, 1)
|
||||
code2 = _class_escape(source, this)
|
||||
else:
|
||||
code2 = LITERAL, this
|
||||
if code1[0] != LITERAL or code2[0] != LITERAL:
|
||||
@ -321,7 +355,7 @@ def _parse(source, pattern, flags=()):
|
||||
code1 = code1[1][0]
|
||||
set.append(code1)
|
||||
|
||||
# FIXME: <fl> move set optimization to support function
|
||||
# FIXME: <fl> move set optimization to compiler!
|
||||
if len(set)==1 and set[0][0] is LITERAL:
|
||||
subpattern.append(set[0]) # optimization
|
||||
elif len(set)==2 and set[0][0] is NEGATE and set[1][0] is LITERAL:
|
||||
@ -335,11 +369,11 @@ def _parse(source, pattern, flags=()):
|
||||
if this == "?":
|
||||
min, max = 0, 1
|
||||
elif this == "*":
|
||||
min, max = 0, sys.maxint
|
||||
min, max = 0, MAXREPEAT
|
||||
elif this == "+":
|
||||
min, max = 1, sys.maxint
|
||||
min, max = 1, MAXREPEAT
|
||||
elif this == "{":
|
||||
min, max = 0, sys.maxint
|
||||
min, max = 0, MAXREPEAT
|
||||
lo = hi = ""
|
||||
while str(source.next) in DIGITS:
|
||||
lo = lo + source.get()
|
||||
@ -358,20 +392,18 @@ def _parse(source, pattern, flags=()):
|
||||
else:
|
||||
raise SyntaxError, "not supported"
|
||||
# figure out which item to repeat
|
||||
# FIXME: should back up to the right mark, right?
|
||||
if subpattern:
|
||||
index = len(subpattern)-1
|
||||
while subpattern[index][0] is MARK:
|
||||
index = index - 1
|
||||
item = subpattern[index:index+1]
|
||||
item = subpattern[-1:]
|
||||
else:
|
||||
raise SyntaxError, "nothing to repeat"
|
||||
if source.match("?"):
|
||||
subpattern[index] = (MIN_REPEAT, (min, max, item))
|
||||
subpattern[-1] = (MIN_REPEAT, (min, max, item))
|
||||
else:
|
||||
subpattern[index] = (MAX_REPEAT, (min, max, item))
|
||||
subpattern[-1] = (MAX_REPEAT, (min, max, item))
|
||||
|
||||
elif this == ".":
|
||||
subpattern.append((ANY, None))
|
||||
|
||||
elif this == "(":
|
||||
group = 1
|
||||
name = None
|
||||
@ -379,28 +411,41 @@ def _parse(source, pattern, flags=()):
|
||||
group = 0
|
||||
# options
|
||||
if source.match("P"):
|
||||
# named group: skip forward to end of name
|
||||
# python extensions
|
||||
if source.match("<"):
|
||||
# named group: skip forward to end of name
|
||||
name = ""
|
||||
while 1:
|
||||
char = source.get()
|
||||
if char is None or char == ">":
|
||||
if char is None:
|
||||
raise SyntaxError, "unterminated name"
|
||||
if char == ">":
|
||||
break
|
||||
# FIXME: check for valid character
|
||||
name = name + char
|
||||
group = 1
|
||||
elif source.match("="):
|
||||
# named backreference
|
||||
raise SyntaxError, "not yet implemented"
|
||||
|
||||
else:
|
||||
char = source.get()
|
||||
if char is None:
|
||||
raise SyntaxError, "unexpected end of pattern"
|
||||
raise SyntaxError, "unknown specifier: ?P%s" % char
|
||||
elif source.match(":"):
|
||||
# non-capturing group
|
||||
group = 2
|
||||
elif source.match_set("iI"):
|
||||
pattern.setflag("i")
|
||||
elif source.match_set("lL"):
|
||||
pattern.setflag("l")
|
||||
elif source.match_set("mM"):
|
||||
pattern.setflag("m")
|
||||
elif source.match_set("sS"):
|
||||
pattern.setflag("s")
|
||||
elif source.match_set("xX"):
|
||||
pattern.setflag("x")
|
||||
elif source.match("#"):
|
||||
# comment
|
||||
while 1:
|
||||
char = source.get()
|
||||
if char is None or char == ")":
|
||||
break
|
||||
else:
|
||||
# flags
|
||||
while FLAGS.has_key(source.next):
|
||||
state.flags = state.flags | FLAGS[source.get()]
|
||||
if group:
|
||||
# parse group contents
|
||||
b = []
|
||||
@ -408,30 +453,25 @@ def _parse(source, pattern, flags=()):
|
||||
# anonymous group
|
||||
group = None
|
||||
else:
|
||||
group = pattern.getgroup(name)
|
||||
if group:
|
||||
subpattern.append((MARK, (group-1)*2))
|
||||
group = state.getgroup(name)
|
||||
while 1:
|
||||
p = _parse(source, pattern, flags)
|
||||
p = _parse(source, state, flags)
|
||||
if source.match(")"):
|
||||
if b:
|
||||
b.append(p)
|
||||
_branch(subpattern, b)
|
||||
else:
|
||||
subpattern.append((SUBPATTERN, (group, p)))
|
||||
p = _branch(state, b)
|
||||
subpattern.append((SUBPATTERN, (group, p)))
|
||||
break
|
||||
elif source.match("|"):
|
||||
b.append(p)
|
||||
else:
|
||||
raise SyntaxError, "group not properly closed"
|
||||
if group:
|
||||
subpattern.append((MARK, (group-1)*2+1))
|
||||
else:
|
||||
# FIXME: should this really be a while loop?
|
||||
while 1:
|
||||
char = source.get()
|
||||
if char is None or char == ")":
|
||||
break
|
||||
# FIXME: skip characters?
|
||||
|
||||
elif this == "^":
|
||||
subpattern.append((AT, AT_BEGINNING))
|
||||
@ -440,7 +480,7 @@ def _parse(source, pattern, flags=()):
|
||||
subpattern.append((AT, AT_END))
|
||||
|
||||
elif this and this[0] == "\\":
|
||||
code =_fixescape(this)
|
||||
code = _escape(source, this, state)
|
||||
subpattern.append(code)
|
||||
|
||||
else:
|
||||
@ -448,13 +488,14 @@ def _parse(source, pattern, flags=()):
|
||||
|
||||
return subpattern
|
||||
|
||||
def parse(source, flags=()):
|
||||
s = Tokenizer(source)
|
||||
g = Pattern()
|
||||
def parse(pattern, flags=0):
|
||||
# parse 're' pattern into list of (opcode, argument) tuples
|
||||
source = Tokenizer(pattern)
|
||||
state = State()
|
||||
b = []
|
||||
while 1:
|
||||
p = _parse(s, g, flags)
|
||||
tail = s.get()
|
||||
p = _parse(source, state, flags)
|
||||
tail = source.get()
|
||||
if tail == "|":
|
||||
b.append(p)
|
||||
elif tail == ")":
|
||||
@ -462,13 +503,32 @@ def parse(source, flags=()):
|
||||
elif tail is None:
|
||||
if b:
|
||||
b.append(p)
|
||||
p = SubPattern(g)
|
||||
_branch(p, b)
|
||||
p = _branch(state, b)
|
||||
break
|
||||
else:
|
||||
raise SyntaxError, "bogus characters at end of regular expression"
|
||||
return p
|
||||
|
||||
def parse_replacement(source, pattern):
|
||||
# parse 're' replacement string into list of literals and
|
||||
# group references
|
||||
s = Tokenizer(source)
|
||||
p = []
|
||||
a = p.append
|
||||
while 1:
|
||||
this = s.get()
|
||||
if this is None:
|
||||
break # end of replacement string
|
||||
if this and this[0] == "\\":
|
||||
try:
|
||||
a(LITERAL, ESCAPES[this])
|
||||
except KeyError:
|
||||
for char in this:
|
||||
a(LITERAL, char)
|
||||
else:
|
||||
a(LITERAL, this)
|
||||
return p
|
||||
|
||||
if __name__ == "__main__":
|
||||
from pprint import pprint
|
||||
from testpatterns import PATTERNS
|
||||
|
||||
Loading…
Reference in New Issue
Block a user