def test_intersect(self):
cfg = CFG([Variable("S"), Variable("A")],
[Terminal("a"), Terminal("b")], [
CFGRule(Variable("S"),
[Variable("A"), Variable("A")]),
CFGRule(Variable("S"), [Terminal("a")]),
CFGRule(Variable("A"), [Terminal("b")])
], Variable("S"))
regex = RegexTree(Node("a"))
fsm = regex.to_fsm()
fsm.close()
cfg_temp = cfg.intersect(fsm)
self.assertFalse(cfg_temp.is_empty())
regex = RegexTree(Node("b"))
fsm = regex.to_fsm()
fsm.close()
cfg_temp = cfg.intersect(fsm)
self.assertFalse(cfg_temp.is_empty())
regex = RegexTree(Node("b,b"))
fsm = regex.to_fsm()
fsm.close()
cfg_temp = cfg.intersect(fsm)
self.assertFalse(cfg_temp.is_empty())
regex = RegexTree(Node("b,a"))
fsm = regex.to_fsm()
fsm.close()
cfg_temp = cfg.intersect(fsm)
self.assertTrue(cfg_temp.is_empty())
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())
