def ParsePosCharGroup(self):
"""Returns a CharClass representing a positive range"""
cClass = CharClass()
nRanges = 0
while True:
savePos = self.pos
if self.theChar == 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.AddChar(u"-")
self.NextChar()
break
else:
# this is all wrong
raise RegularExpressionError(
"hyphen must be first or last character in posCharGroup [%i]"
% self.pos)
try:
cClass.AddClass(self.ParseCharRange())
nRanges += 1
continue
except RegularExpressionError:
self.SetPos(savePos)
pass
try:
cClass.AddClass(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
