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Issues #814253, #9179: Group references and conditional group references now

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work in lookbehind assertions in regular expressions.
This commit is contained in:
Serhiy Storchaka 2014-11-07 21:43:57 +02:00
parent b556399fb5
commit 84df7fe6a2
4 changed files with 67 additions and 12 deletions
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33
Lib/sre_parse.py
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@ -66,24 +66,25 @@ class Pattern:
# master pattern object. keeps track of global attributes
def __init__(self):
self.flags = 0
self.open = []
self.groups = 1
self.groupdict = {}
self.subpatterns = [None] # group 0
@property
def groups(self):
return len(self.subpatterns)
def opengroup(self, name=None):
gid = self.groups
self.groups = gid + 1
self.subpatterns.append(None)
if name is not None:
ogid = self.groupdict.get(name, None)
if ogid is not None:
raise error("redefinition of group name %s as group %d; "
"was group %d" % (repr(name), gid, ogid))
self.groupdict[name] = gid
self.open.append(gid)
return gid
def closegroup(self, gid):
self.open.remove(gid)
def closegroup(self, gid, p):
self.subpatterns[gid] = p
def checkgroup(self, gid):
return gid < self.groups and gid not in self.open
return gid < self.groups and self.subpatterns[gid] is not None
class SubPattern:
# a subpattern, in intermediate form
@ -181,7 +182,21 @@ class SubPattern:
elif op in UNITCODES:
lo = lo + 1
hi = hi + 1
elif op == SUCCESS:
elif op is GROUPREF:
i, j = self.pattern.subpatterns[av].getwidth()
lo = lo + i
hi = hi + j
elif op is GROUPREF_EXISTS:
i, j = av[1].getwidth()
if av[2] is not None:
l, h = av[2].getwidth()
i = min(i, l)
j = max(j, h)
else:
i = 0
lo = lo + i
hi = hi + j
elif op is SUCCESS:
break
self.width = min(lo, MAXREPEAT - 1), min(hi, MAXREPEAT)
return self.width
@ -709,7 +724,7 @@ def _parse(source, state):
if not sourcematch(")"):
raise error("unbalanced parenthesis")
if group is not None:
state.closegroup(group)
state.closegroup(group, p)
subpatternappend((SUBPATTERN, (group, p)))
else:
while 1: