def test_to_pda(self):
cfg = CFG([Variable("E"), Variable("I")], [
Terminal("a"),
Terminal("b"),
Terminal("0"),
Terminal("1"),
Terminal("+"),
Terminal("*"),
Terminal("("),
Terminal(")")
], [
CFGRule(Variable("I"), [Terminal("a")]),
CFGRule(Variable("I"), [Terminal("b")]),
CFGRule(Variable("I"),
[Variable("I"), Terminal("a")]),
CFGRule(Variable("I"),
[Variable("I"), Terminal("b")]),
CFGRule(Variable("I"),
[Variable("I"), Terminal("0")]),
CFGRule(Variable("I"),
[Variable("I"), Terminal("1")]),
CFGRule(Variable("E"), [Variable("I")]),
CFGRule(
Variable("E"),
[Variable("E"), Terminal("*"),
Variable("E")]),
CFGRule(
Variable("E"),
[Variable("E"), Terminal("+"),
Variable("E")]),
CFGRule(
Variable("E"),
[Terminal("("), Variable("E"),
Terminal(")")])
], Variable("E"))
pda = cfg.to_PDA()
self.assertIsInstance(pda, PDA)
self.assertIn(
PDATransitionFunction(PDAState("q"), "epsilon", Variable("I"),
PDAState("q"), [Terminal("a")]),
pda.transition_function)
self.assertIn(
PDATransitionFunction(PDAState("q"), "epsilon", Variable("I"),
PDAState("q"),
[Variable("I"), Terminal("0")]),
pda.transition_function)
self.assertIn(
PDATransitionFunction(PDAState("q"), "epsilon", Variable("E"),
PDAState("q"), [Variable("I")]),
pda.transition_function)
self.assertEqual(18, len(pda.transition_function))
self.assertTrue(pda.accepts_by_empty_stack([Terminal("a")], 100))
self.assertTrue(pda.accepts_by_empty_stack([Terminal("b")], 100))
self.assertFalse(
pda.accepts_by_empty_stack([Terminal(x) for x in "b0"], 100))
self.assertTrue(
pda.accepts_by_empty_stack([Terminal(x) for x in "b0"], 1000))
self.assertTrue(
pda.accepts_by_empty_stack([Terminal(x) for x in "b00"], 10000))
