#!/usr/bin/env python
from characterset import CharacterSet, distinctCharacterSets
from fsm import State, StateMachine
class NFAState(State):
pass
class NFA(StateMachine):
@classmethod
def fnmatch(klass, s):
'''create an NFA state machine representing the fnmatch pattern @s'''
nfa = NFA(NFAState())
state = nfa.initial
new_state = None
chars = list(s)
while True:
if len(chars) == 0: break # end-of-string
c = chars.pop(0)
new_state = NFAState()
nfa.states.append(new_state)
if c == '?':
# single-character wildcard
state.add(CharacterSet.excluding(''), new_state)
elif c == '*':
# multi-character wildcard
state.add(CharacterSet.excluding(''), new_state)
new_state.add(CharacterSet.excluding(''), new_state)
elif c == '\\':
# treat the next character literally
if len(chars) == 0:
raise 'escape at end of string'
c = chars.pop(0)
state.add(CharacterSet.including(c), new_state)
elif c == '[':
# bracket expression
try:
c = chars.pop(0)
if c == '!': # inverted
inverted = True
c = chars.pop(0)
else:
inverted = False
charset = CharacterSet.including('')
last_char = None
while c != ']':
if c == '-' and last_char:
c = chars.pop(0)
charset = charset.union(CharacterSet.range(last_char, c))
last_char = None
c = chars.pop(0)
continue
charset = charset.union(CharacterSet.including(c))
last_char = c # save last character
c = sio.read(1)
except IndexError, e:
raise 'unterminated bracket expression'
if inverted:
state.add(CharacterSet.excluding('') - charset, new_state)
else:
state.add(charset, new_state)
else:
state.add(CharacterSet.including(c), new_state)
state = new_state
state.match = True
return nfa
def __init__(self, initial, states=[]):
StateMachine.__init__(self, initial, states)
