def __init_productions_to_CFG(self, start):
productions = []
for p in self.states:
productions.append(
CFGRule(start, [
self.__get_variable(
str(self.start_state) + "," + str(self.start_symbol) +
"," + str(p))
]))
return productions
def __init__(self, terminals, query):
self.variables = [Variable("S"), Variable("C")]
self.terminals = terminals[:]
self.productions = [
CFGRule(
Variable("S"),
[Variable("C"), Terminal(query),
Variable("C")]),
CFGRule(Variable("C"),
[Variable("C"), Variable("C")]),
CFGRule(Variable("C"), [])
]
for terminal in self.terminals:
self.productions.append(
CFGRule(Variable("C"), [
Terminal(terminal),
Variable("C"),
Terminal(inverse(terminal))
]))
self.start = Variable("S")
self.__empty = None
def test_emptiness(self):
cfg = CFG([Variable("S"), Variable("A"),
Variable("B")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"),
[Variable("A"), Variable("B")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")])
], Variable("S"))
self.assertEqual(
set([Variable("S"),
Variable("A"),
Terminal("a"),
Terminal("b")]), cfg.get_reachable())
self.assertFalse(cfg.is_empty())
cfg = CFG([Variable("S"), Variable("A"),
Variable("B")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"),
[Variable("A"), Variable("B")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")])
], Variable("B"))
self.assertEqual(
set([Variable("S"),
Variable("A"),
Terminal("a"),
Terminal("b")]), cfg.get_reachable())
self.assertTrue(cfg.is_empty())
def test_repr(self):
cfg = CFG([Variable("I"), Variable("J")],
[Terminal("a"), Terminal("b")],
[CFGRule(Variable("I"),
[Terminal("a"), Variable("I")])], Variable("I"))
r = str(cfg)
self.assertIn(str(Variable("I")), r)
self.assertIn(str(Variable("J")), r)
self.assertIn(str(Terminal("a")), r)
self.assertIn(str(Terminal("b")), r)
self.assertIn("Variables", r)
self.assertIn("Terminals", r)
self.assertIn("Productions", r)
self.assertIn("Start", r)
self.assertEqual(r.count("->"), 1)
self.assertEqual(r.count("\n"), 4)
def test_paper(self):
cfg = CFG([Variable("S"), Variable("C")], [
Terminal("a"),
Terminal("b"),
Terminal("c"),
Terminal("q"),
Terminal("am"),
Terminal("bm"),
Terminal("cm"),
Terminal("qm")
], [
CFGRule(
Variable("S"),
[Variable("C"), Terminal("q"),
Variable("C")]),
CFGRule(
Variable("C"),
[Terminal("a"), Variable("C"),
Terminal("am")]),
CFGRule(
Variable("C"),
[Terminal("b"), Variable("C"),
Terminal("bm")]),
CFGRule(
Variable("C"),
[Terminal("c"), Variable("C"),
Terminal("cm")]),
CFGRule(
Variable("C"),
[Terminal("q"), Variable("C"),
Terminal("qm")]),
CFGRule(Variable("C"),
[Variable("C"), Variable("C")]),
CFGRule(Variable("C"), [])
], Variable("S"))
regex = RegexTree(Node("(a,b)|(bm,c)|(cm,am,q)"))
fsm = regex.to_fsm()
fsm.close()
cfg_temp = cfg.intersect(fsm)
self.assertFalse(cfg_temp.is_empty())
regex = RegexTree(Node("(a,b)|(b,c)|(cm,am,q)"))
fsm = regex.to_fsm()
fsm.close()
cfg_temp = cfg.intersect(fsm)
self.assertTrue(cfg_temp.is_empty())
def __process_states_transition(self, trans, productions, states, size):
head = self.__get_head(trans, size, states)
body = self.__get_body(trans, size, states)
productions.append(CFGRule(head, body))
def test_iter(self):
cfg = CFG([Variable("S"),
Variable("A"),
Variable("B"),
Variable("C")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"),
[Variable("A"), Variable("B")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")]),
CFGRule(Variable("A"), [Variable("C")])
], Variable("S"))
words = [x for x in cfg]
self.assertEqual(words, [[Terminal("a")]])
cfg = CFG([Variable("S"), Variable("A"),
Variable("C")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"), [Variable("A")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")]),
CFGRule(Variable("A"), [Variable("C")])
], Variable("S"))
words = [x for x in cfg]
self.assertIn([Terminal("a")], words)
self.assertIn([Terminal("b")], words)
self.assertEqual(len(words), 2)
cfg = CFG([Variable("S"), Variable("A"),
Variable("B")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"),
[Variable("S"), Variable("S")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")])
], Variable("S"))
it = iter(cfg)
word = next(it)
self.assertEqual(set(word), set([Terminal("a")]))
word = next(it)
self.assertEqual(set(word), set([Terminal("a")]))
word = next(it)
self.assertEqual(set(word), set([Terminal("a")]))
word = next(it)
self.assertEqual(set(word), set([Terminal("a")]))
word = next(it)
self.assertEqual(set(word), set([Terminal("a")]))
cfg = CFG([Variable("S"), Variable("A"),
Variable("B")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"),
[Variable("A"), Variable("S")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")])
], Variable("S"))
it = iter(cfg)
temp = [next(it) for _ in range(100)]
self.assertIn(
[Terminal("b"),
Terminal("b"),
Terminal("b"),
Terminal("a")], temp)