def parse_qualified(self):
"""
Parse the string from its current index into a repetition or an expression that can be contained by an repetition.
@return: a visitable regular expression object from the Regex package.
"""
child = self.parse_character()
if self.get_next_if(u'*'):
return Regex.Repetition(child, 0, Regex.Repetition.Infinity)
elif self.get_next_if(u'+'):
return Regex.Repetition(child, 1, Regex.Repetition.Infinity)
elif self.get_next_if(u'?'):
return Regex.Repetition(child, 0, 1)
# Need to look ahead two characters because it might be a variable following this one
elif self.next_is(u'{') and self.nth_next_is_not(
2, string.ascii_letters + '.'):
self.get_next()
return self.parse_repetition(child)
else:
return child
def parse_repetition(self, child):
"""
Parse a {min, max} expression from the string at its current index
@param child: a visital object from the Regex package containing the repeated expression.
@return: a Regex.Repetition object representing the repetition.
"""
first = self.parse_integer()
self.expect(u',')
last = self.parse_integer()
self.expect(u'}')
if first > last:
raise RegexParserExceptionInternal(
"Minimum repetition (%d) cannot be larger than maximum repetition (%d)."
% (first, last))
return Regex.Repetition(child, first, last)
def visit_repetition(self, repetition):
new_repetition = Regex.Repetition(None, repetition.min, repetition.max)
repetition.child.accept(self)
new_repetition.child = self.stack.pop()
self.stack.append(new_repetition)