def compileConjunction(self):
fsa = None
while self.peekToken() and self.peekToken() not in (')', '|'):
sequence = self.compileSequence()
fsa = fsa and FSA.intersection(fsa, sequence) or sequence
self.skipTokens(['&'])
return fsa
def compileConjunction(self):
fsa = None
while self.peekToken() and self.peekToken() not in (')', '|'):
sequence = self.compileSequence()
fsa = fsa and FSA.intersection(fsa, sequence) or sequence
self.skipTokens(['&'])
return fsa
def compileItem(self):
startPosition = self.index
c = self.readToken()
if c == '(':
fsa = self.compileExpr()
if self.readToken() != ')':
raise ValueError("missing ')'")
elif c == '~':
fsa = FSA.complement(self.compileItem())
else:
fsa = FSA.singleton(c, arcMetadata=self.recordSourcePositions and [startPosition])
while self.peekChar() and self.peekChar() in '?*+':
c = self.readChar()
if c == '*':
fsa = FSA.closure(fsa)
elif c == '?':
fsa = FSA.union(fsa, FSA.EMPTY_STRING_FSA)
elif c == '+':
fsa = FSA.iteration(fsa)
else:
raise ValueError('program error')
return fsa
def compileItem(self):
startPosition = self.index
c = self.readToken()
if c == '(':
fsa = self.compileExpr()
if self.readToken() != ')':
raise ValueError("missing ')'")
elif c == '~':
fsa = FSA.complement(self.compileItem())
else:
fsa = FSA.singleton(c,
arcMetadata=self.recordSourcePositions
and [startPosition])
while self.peekChar() and self.peekChar() in '?*+':
c = self.readChar()
if c == '*':
fsa = FSA.closure(fsa)
elif c == '?':
fsa = FSA.union(fsa, FSA.EMPTY_STRING_FSA)
elif c == '+':
fsa = FSA.iteration(fsa)
else:
raise ValueError('program error')
return fsa
def compileSequence(self):
fsa = FSA.EMPTY_STRING_FSA
while self.peekToken() and self.peekToken() not in (')', '|', '&'):
fsa = FSA.concatenation(fsa, self.compileItem())
return fsa
def compileExpr(self):
fsa = FSA.NULL_FSA
while self.peekToken() and self.peekToken() != ')':
fsa = FSA.union(fsa, self.compileConjunction())
self.skipTokens(['|'])
return fsa
def compileSequence(self):
fsa = FSA.EMPTY_STRING_FSA
while self.peekToken() and self.peekToken() not in (')', '|', '&'):
fsa = FSA.concatenation(fsa, self.compileItem())
return fsa
def compileExpr(self):
fsa = FSA.NULL_FSA
while self.peekToken() and self.peekToken() != ')':
fsa = FSA.union(fsa, self.compileConjunction())
self.skipTokens(['|'])
return fsa
