def ParsePosCharGroup(self):
"""Returns a CharClass representing a positive range"""
cClass = CharClass()
nRanges = 0
while True:
savepos = self.pos
if self.the_char == u"-" and nRanges:
# This had better be the last hyphen in the posCharGroup
if self.match(u"-["):
# a subtraction
break
elif self.match(u"-]") or self.match(u"--["):
cClass.add_char(u"-")
self.next_char()
break
else:
# this is all wrong
raise RegularExpressionError(
"hyphen must be first or last character in posCharGroup [%i]" % self.pos)
try:
cClass.add_class(self.ParseCharRange())
nRanges += 1
continue
except RegularExpressionError:
self.setpos(savepos)
pass
try:
cClass.add_class(self.ParseCharClassEsc())
nRanges += 1
continue
except RegularExpressionError:
if nRanges:
self.setpos(savepos)
break
else:
# We expected either a charRange or a charClassEsc
raise RegularExpressionError(
"Expected charRange or charClassEsc at [%i]" % self.pos)
return cClass
