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authorGuido van Rossum <guido@python.org>2000-04-10 17:10:48 (GMT)
committerGuido van Rossum <guido@python.org>2000-04-10 17:10:48 (GMT)
commitb81e70ebdb28246e427249d386518bc03d08c959 (patch)
tree4f2ba435b4815d7ff7f4f6abab7505fb16f4c7c7 /Lib/sre_parse.py
parent5de435a245fd7158b1a8db1201154ad73fd4bf13 (diff)
downloadcpython-b81e70ebdb28246e427249d386518bc03d08c959.zip
cpython-b81e70ebdb28246e427249d386518bc03d08c959.tar.gz
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Fredrik Lundh: new snapshot. Mostly reindented.
This one should work with unicode expressions, and compile a bit more silently.
Diffstat (limited to 'Lib/sre_parse.py')
-rw-r--r--Lib/sre_parse.py723
1 files changed, 364 insertions, 359 deletions
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index db4c500..8b68ea1 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -26,8 +26,11 @@ from sre_constants import *
SPECIAL_CHARS = ".\\[{()*+?^$|"
REPEAT_CHARS = "*+?{"
-OCTDIGITS = "01234567"
-HEXDIGITS = "0123456789abcdefABCDEF"
+# FIXME: string in tuple tests may explode with if char is unicode :-(
+DIGITS = tuple(string.digits)
+
+OCTDIGITS = tuple("01234567")
+HEXDIGITS = tuple("0123456789abcdefABCDEF")
ESCAPES = {
"\\a": (LITERAL, chr(7)),
@@ -55,168 +58,168 @@ CATEGORIES = {
class Pattern:
# FIXME: <fl> rename class, and store flags in here too!
def __init__(self):
- self.flags = []
- self.groups = 1
- self.groupdict = {}
+ self.flags = []
+ self.groups = 1
+ self.groupdict = {}
def getgroup(self, name=None):
- gid = self.groups
- self.groups = gid + 1
- if name:
- self.groupdict[name] = gid
- return gid
+ gid = self.groups
+ self.groups = gid + 1
+ if name:
+ self.groupdict[name] = gid
+ return gid
def setflag(self, flag):
- if flag not in self.flags:
- self.flags.append(flag)
+ if flag in self.flags:
+ self.flags.append(flag)
class SubPattern:
# a subpattern, in intermediate form
def __init__(self, pattern, data=None):
- self.pattern = pattern
- if not data:
- data = []
- self.data = data
- self.flags = []
- self.width = None
+ self.pattern = pattern
+ if not data:
+ data = []
+ self.data = data
+ self.flags = []
+ self.width = None
def __repr__(self):
- return repr(self.data)
+ return repr(self.data)
def __len__(self):
- return len(self.data)
+ return len(self.data)
def __delitem__(self, index):
- del self.data[index]
+ del self.data[index]
def __getitem__(self, index):
- return self.data[index]
+ return self.data[index]
def __setitem__(self, index, code):
- self.data[index] = code
+ self.data[index] = code
def __getslice__(self, start, stop):
- return SubPattern(self.pattern, self.data[start:stop])
+ return SubPattern(self.pattern, self.data[start:stop])
def insert(self, index, code):
- self.data.insert(index, code)
+ self.data.insert(index, code)
def append(self, code):
- self.data.append(code)
+ self.data.append(code)
def getwidth(self):
- # determine the width (min, max) for this subpattern
- if self.width:
- return self.width
- lo = hi = 0L
- for op, av in self.data:
- if op is BRANCH:
- l = sys.maxint
- h = 0
- for av in av[1]:
- i, j = av.getwidth()
- l = min(l, i)
- h = min(h, j)
- lo = lo + i
- hi = hi + j
- elif op is CALL:
- i, j = av.getwidth()
- lo = lo + i
- hi = hi + j
- elif op is SUBPATTERN:
- i, j = av[1].getwidth()
- lo = lo + i
- 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]
- elif op in (ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY):
- lo = lo + 1
- hi = hi + 1
- elif op == SUCCESS:
- break
- self.width = int(min(lo, sys.maxint)), int(min(hi, sys.maxint))
- return self.width
+ # determine the width (min, max) for this subpattern
+ if self.width:
+ return self.width
+ lo = hi = 0L
+ for op, av in self.data:
+ if op is BRANCH:
+ l = sys.maxint
+ h = 0
+ for av in av[1]:
+ i, j = av.getwidth()
+ l = min(l, i)
+ h = min(h, j)
+ lo = lo + i
+ hi = hi + j
+ elif op is CALL:
+ i, j = av.getwidth()
+ lo = lo + i
+ hi = hi + j
+ elif op is SUBPATTERN:
+ i, j = av[1].getwidth()
+ lo = lo + i
+ 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]
+ elif op in (ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY):
+ lo = lo + 1
+ hi = hi + 1
+ elif op == SUCCESS:
+ 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)
+ if not flag in self.flags:
+ self.flags.append(flag)
def reset(self, flag):
- if flag in self.flags:
- self.flags.remove(flag)
+ if flag in self.flags:
+ self.flags.remove(flag)
class Tokenizer:
def __init__(self, string):
- self.string = list(string)
- self.next = self.__next()
+ self.string = list(string)
+ self.next = self.__next()
def __next(self):
- if not self.string:
- return None
- char = self.string[0]
- if char[0] == "\\":
- try:
- c = self.string[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 c not in HEXDIGITS:
- break
- char = char + c
- elif c in string.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 c not in string.digits:
- break
- char = char + c
- except IndexError:
- pass # use what we've got this far
- del self.string[0:len(char)]
- return char
+ if not self.string:
+ return None
+ char = self.string[0]
+ if char[0] == "\\":
+ try:
+ c = self.string[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)]
+ return char
def match(self, char):
- if char == self.next:
- self.next = self.__next()
- return 1
- return 0
+ if char == self.next:
+ self.next = self.__next()
+ return 1
+ return 0
def match_set(self, set):
- if self.next in set:
- self.next = self.__next()
- return 1
- return 0
+ if self.next and self.next in set:
+ self.next = self.__next()
+ return 1
+ return 0
def get(self):
- this = self.next
- self.next = self.__next()
- return this
+ this = self.next
+ 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)
+ # 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)
+ code = CATEGORIES.get(escape)
+ if code:
+ return code
+ code = ESCAPES.get(escape)
if code:
- return 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:
+ 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":
- escape = escape[2:]
- return LITERAL, chr(string.atoi(escape[-2:], 16) & 0xff)
- elif escape[1:2] in string.digits:
- return LITERAL, chr(string.atoi(escape[1:], 8) & 0xff)
- elif len(escape) == 2:
- return LITERAL, escape[1]
+ if escape[1:2] == "x":
+ 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:
+ return LITERAL, escape[1]
except ValueError:
- pass
+ pass
raise SyntaxError, "bogus escape: %s" % repr(escape)
def _branch(subpattern, items):
@@ -226,35 +229,35 @@ def _branch(subpattern, items):
# check if all items share a common prefix
while 1:
- prefix = None
- for item in items:
- if not item:
- break
- if prefix is None:
- prefix = item[0]
- elif item[0] != prefix:
- break
- else:
- # all subitems start with a common "prefix".
- # move it out of the branch
- for item in items:
- del item[0]
- subpattern.append(prefix)
- continue # check next one
- break
+ prefix = None
+ for item in items:
+ if not item:
+ break
+ if prefix is None:
+ prefix = item[0]
+ elif item[0] != prefix:
+ break
+ else:
+ # all subitems start with a common "prefix".
+ # move it out of the branch
+ for item in items:
+ del item[0]
+ subpattern.append(prefix)
+ continue # check next one
+ break
# check if the branch can be replaced by a character set
for item in items:
- if len(item) != 1 or item[0][0] != LITERAL:
- break
+ if len(item) != 1 or item[0][0] != LITERAL:
+ break
else:
- # we can store this as a character set instead of a
- # branch (FIXME: use a range if possible)
- set = []
- for item in items:
- set.append(item[0])
- subpattern.append((IN, set))
- return
+ # we can store this as a character set instead of a
+ # branch (FIXME: use a range if possible)
+ set = []
+ for item in items:
+ set.append(item[0])
+ subpattern.append((IN, set))
+ return
subpattern.append((BRANCH, (None, items)))
@@ -268,178 +271,180 @@ def _parse(source, pattern, flags=()):
while 1:
- if source.next in ("|", ")"):
- break # end of subpattern
- this = source.get()
- if this is None:
- break # end of pattern
-
- if this and this[0] not in SPECIAL_CHARS:
- subpattern.append((LITERAL, this))
-
- elif this == "[":
- # character set
- set = []
-## if source.match(":"):
-## pass # handle character classes
- if source.match("^"):
- set.append((NEGATE, None))
- # check remaining characters
- start = set[:]
- while 1:
- this = source.get()
- if this == "]" and set != start:
- break
- elif this and this[0] == "\\":
- code1 = _fixescape(this, 1)
- elif this:
- code1 = LITERAL, this
- else:
- raise SyntaxError, "unexpected end of regular expression"
- if source.match("-"):
- # potential range
- this = source.get()
- if this == "]":
- set.append(code1)
- set.append((LITERAL, "-"))
- break
- else:
- if this[0] == "\\":
- code2 = _fixescape(this, 1)
- else:
- code2 = LITERAL, this
- if code1[0] != LITERAL or code2[0] != LITERAL:
- raise SyntaxError, "illegal range"
- if len(code1[1]) != 1 or len(code2[1]) != 1:
- raise SyntaxError, "illegal range"
- set.append((RANGE, (code1[1], code2[1])))
- else:
- if code1[0] is IN:
- code1 = code1[1][0]
- set.append(code1)
-
- # FIXME: <fl> move set optimization to support function
- 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:
- subpattern.append((NOT_LITERAL, set[1][1])) # optimization
- else:
- # FIXME: <fl> add charmap optimization
- subpattern.append((IN, set))
-
- elif this and this[0] in REPEAT_CHARS:
- # repeat previous item
- if this == "?":
- min, max = 0, 1
- elif this == "*":
- min, max = 0, sys.maxint
- elif this == "+":
- min, max = 1, sys.maxint
- elif this == "{":
- min, max = 0, sys.maxint
- lo = hi = ""
- while source.next in string.digits:
- lo = lo + source.get()
- if source.match(","):
- while source.next in string.digits:
- hi = hi + source.get()
- else:
- hi = lo
- if not source.match("}"):
- raise SyntaxError, "bogus range"
- if lo:
- min = int(lo)
- if hi:
- max = int(hi)
- # FIXME: <fl> check that hi >= lo!
- 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]
- else:
- raise SyntaxError, "nothing to repeat"
- if source.match("?"):
- subpattern[index] = (MIN_REPEAT, (min, max, item))
- else:
- subpattern[index] = (MAX_REPEAT, (min, max, item))
- elif this == ".":
- subpattern.append((ANY, None))
- elif this == "(":
- group = 1
- name = None
- if source.match("?"):
- group = 0
- # options
- if source.match("P"):
- # named group: skip forward to end of name
- if source.match("<"):
- name = ""
- while 1:
- char = source.get()
- if char in (">", None):
- break
- name = name + char
- group = 1
- 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")
- if group:
- # parse group contents
- b = []
- if group == 2:
- # anonymous group
- group = None
- else:
- group = pattern.getgroup(name)
- if group:
- subpattern.append((MARK, (group-1)*2))
- while 1:
- p = _parse(source, pattern, flags)
- if source.match(")"):
- if b:
- b.append(p)
- _branch(subpattern, b)
- else:
- 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 source.get() not in (")", None):
- pass
-
- elif this == "^":
- subpattern.append((AT, AT_BEGINNING))
-
- elif this == "$":
- subpattern.append((AT, AT_END))
-
- elif this and this[0] == "\\":
- code =_fixescape(this)
- subpattern.append(code)
-
- else:
- raise SyntaxError, "parser error"
+ if str(source.next) in ("|", ")"):
+ break # end of subpattern
+ this = source.get()
+ if this is None:
+ break # end of pattern
+
+ if this and this[0] not in SPECIAL_CHARS:
+ subpattern.append((LITERAL, this))
+
+ elif this == "[":
+ # character set
+ set = []
+## if source.match(":"):
+## pass # handle character classes
+ if source.match("^"):
+ set.append((NEGATE, None))
+ # check remaining characters
+ start = set[:]
+ while 1:
+ this = source.get()
+ if this == "]" and set != start:
+ break
+ elif this and this[0] == "\\":
+ code1 = _fixescape(this, 1)
+ elif this:
+ code1 = LITERAL, this
+ else:
+ raise SyntaxError, "unexpected end of regular expression"
+ if source.match("-"):
+ # potential range
+ this = source.get()
+ if this == "]":
+ set.append(code1)
+ set.append((LITERAL, "-"))
+ break
+ else:
+ if this[0] == "\\":
+ code2 = _fixescape(this, 1)
+ else:
+ code2 = LITERAL, this
+ if code1[0] != LITERAL or code2[0] != LITERAL:
+ raise SyntaxError, "illegal range"
+ if len(code1[1]) != 1 or len(code2[1]) != 1:
+ raise SyntaxError, "illegal range"
+ set.append((RANGE, (code1[1], code2[1])))
+ else:
+ if code1[0] is IN:
+ code1 = code1[1][0]
+ set.append(code1)
+
+ # FIXME: <fl> move set optimization to support function
+ 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:
+ subpattern.append((NOT_LITERAL, set[1][1])) # optimization
+ else:
+ # FIXME: <fl> add charmap optimization
+ subpattern.append((IN, set))
+
+ elif this and this[0] in REPEAT_CHARS:
+ # repeat previous item
+ if this == "?":
+ min, max = 0, 1
+ elif this == "*":
+ min, max = 0, sys.maxint
+ elif this == "+":
+ min, max = 1, sys.maxint
+ elif this == "{":
+ min, max = 0, sys.maxint
+ lo = hi = ""
+ while str(source.next) in DIGITS:
+ lo = lo + source.get()
+ if source.match(","):
+ while str(source.next) in DIGITS:
+ hi = hi + source.get()
+ else:
+ hi = lo
+ if not source.match("}"):
+ raise SyntaxError, "bogus range"
+ if lo:
+ min = int(lo)
+ if hi:
+ max = int(hi)
+ # FIXME: <fl> check that hi >= lo!
+ 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]
+ else:
+ raise SyntaxError, "nothing to repeat"
+ if source.match("?"):
+ subpattern[index] = (MIN_REPEAT, (min, max, item))
+ else:
+ subpattern[index] = (MAX_REPEAT, (min, max, item))
+ elif this == ".":
+ subpattern.append((ANY, None))
+ elif this == "(":
+ group = 1
+ name = None
+ if source.match("?"):
+ group = 0
+ # options
+ if source.match("P"):
+ # named group: skip forward to end of name
+ if source.match("<"):
+ name = ""
+ while 1:
+ char = source.get()
+ if char is None or char == ">":
+ break
+ name = name + char
+ group = 1
+ 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")
+ if group:
+ # parse group contents
+ b = []
+ if group == 2:
+ # anonymous group
+ group = None
+ else:
+ group = pattern.getgroup(name)
+ if group:
+ subpattern.append((MARK, (group-1)*2))
+ while 1:
+ p = _parse(source, pattern, flags)
+ if source.match(")"):
+ if b:
+ b.append(p)
+ _branch(subpattern, b)
+ else:
+ 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
+
+ elif this == "^":
+ subpattern.append((AT, AT_BEGINNING))
+
+ elif this == "$":
+ subpattern.append((AT, AT_END))
+
+ elif this and this[0] == "\\":
+ code =_fixescape(this)
+ subpattern.append(code)
+
+ else:
+ raise SyntaxError, "parser error"
return subpattern
@@ -448,20 +453,20 @@ def parse(source, flags=()):
g = Pattern()
b = []
while 1:
- p = _parse(s, g, flags)
- tail = s.get()
- if tail == "|":
- b.append(p)
- elif tail == ")":
- raise SyntaxError, "unbalanced parenthesis"
- elif tail is None:
- if b:
- b.append(p)
- p = SubPattern(g)
- _branch(p, b)
- break
- else:
- raise SyntaxError, "bogus characters at end of regular expression"
+ p = _parse(s, g, flags)
+ tail = s.get()
+ if tail == "|":
+ b.append(p)
+ elif tail == ")":
+ raise SyntaxError, "unbalanced parenthesis"
+ elif tail is None:
+ if b:
+ b.append(p)
+ p = SubPattern(g)
+ _branch(p, b)
+ break
+ else:
+ raise SyntaxError, "bogus characters at end of regular expression"
return p
if __name__ == "__main__":
@@ -469,23 +474,23 @@ if __name__ == "__main__":
from testpatterns import PATTERNS
a = b = c = 0
for pattern, flags in PATTERNS:
- if flags:
- continue
- print "-"*68
- try:
- p = parse(pattern)
- print repr(pattern), "->"
- pprint(p.data)
- import sre_compile
- try:
- code = sre_compile.compile(p)
- c = c + 1
- except:
- pass
- a = a + 1
- except SyntaxError, v:
- print "**", repr(pattern), v
- b = b + 1
+ if flags:
+ continue
+ print "-"*68
+ try:
+ p = parse(pattern)
+ print repr(pattern), "->"
+ pprint(p.data)
+ import sre_compile
+ try:
+ code = sre_compile.compile(p)
+ c = c + 1
+ except:
+ pass
+ a = a + 1
+ except SyntaxError, v:
+ print "**", repr(pattern), v
+ b = b + 1
print "-"*68
print a, "of", b, "patterns successfully parsed"
print c, "of", b, "patterns successfully compiled"