def test_intersection_with_epsilon(self):
state0 = State(0)
state1 = State(1)
symb_a = Symbol("a")
dfa = DeterministicFiniteAutomaton({state0, state1}, {symb_a},
start_state=state0,
final_states={state1})
dfa.add_transition(state0, symb_a, state1)
self.assertTrue(dfa.accepts([symb_a]))
ter_a = Terminal("a")
var_s = Variable("S")
var_l = Variable("L")
var_t = Variable("T")
productions = {
Production(var_s, [var_l, var_t]),
Production(var_l, [Epsilon()]),
Production(var_t, [ter_a])
}
cfg = CFG(productions=productions, start_symbol=var_s)
self.assertFalse(cfg.is_empty())
self.assertTrue(cfg.contains([ter_a]))
cfg_temp = cfg.to_pda().to_cfg()
self.assertFalse(cfg_temp.is_empty())
self.assertTrue(cfg_temp.contains([ter_a]))
cfg_temp = cfg.to_pda().to_final_state().to_empty_stack().to_cfg()
self.assertFalse(cfg_temp.is_empty())
self.assertTrue(cfg_temp.contains([ter_a]))
cfg_i = cfg.intersection(dfa)
self.assertFalse(cfg_i.is_empty())
def _test_profiling_conversions():
""" Tests multiple conversions """
ter_a = Terminal("a")
ter_b = Terminal("b")
ter_c = Terminal("c")
var_s = Variable("S")
productions = {
Production(var_s, [ter_a, var_s, ter_b]),
Production(var_s, [ter_c])
}
cfg = CFG(productions=productions, start_symbol=var_s)
cfg = cfg.to_pda().to_final_state().to_empty_stack().to_cfg()
cfg = cfg.to_pda().to_final_state().to_empty_stack().to_cfg()
cfg.to_pda().to_final_state().to_empty_stack().to_cfg()
def test_to_pda(self):
""" Tests the conversion to PDA """
var_e = Variable("E")
var_i = Variable("I")
ter_a = Terminal("a")
ter_b = Terminal("b")
ter_0 = Terminal("0")
ter_1 = Terminal("1")
ter_par_open = Terminal("(")
ter_par_close = Terminal(")")
ter_mult = Terminal("*")
ter_plus = Terminal("+")
productions = {
Production(var_e, [var_i]),
Production(var_e, [var_e, ter_plus, var_e]),
Production(var_e, [var_e, ter_mult, var_e]),
Production(var_e, [ter_par_open, var_e, ter_par_close]),
Production(var_i, [ter_a]),
Production(var_i, [ter_b]),
Production(var_i, [var_i, ter_a]),
Production(var_i, [var_i, ter_b]),
Production(var_i, [var_i, ter_0]),
Production(var_i, [var_i, ter_1]),
Production(var_i, [var_i, Epsilon()])
}
cfg = CFG({var_e, var_i}, {
ter_a, ter_b, ter_0, ter_1, ter_par_open, ter_par_close, ter_mult,
ter_plus
}, var_e, productions)
pda = cfg.to_pda()
self.assertEqual(len(pda.states), 1)
self.assertEqual(len(pda.final_states), 0)
self.assertEqual(len(pda.input_symbols), 8)
self.assertEqual(len(pda.stack_symbols), 10)
self.assertEqual(pda.get_number_transitions(), 19)
def test_conversions(self):
""" Tests multiple conversions """
ter_a = Terminal("a")
ter_b = Terminal("b")
ter_c = Terminal("c")
var_s = Variable("S")
productions = {
Production(var_s, [ter_a, var_s, ter_b]),
Production(var_s, [ter_c])
}
cfg = CFG(productions=productions, start_symbol=var_s)
cfg = cfg.to_pda().to_final_state().to_empty_stack().to_cfg()
self.assertTrue(cfg.contains([ter_c]))
self.assertTrue(cfg.contains([ter_a, ter_c, ter_b]))
self.assertTrue(cfg.contains([ter_a, ter_a, ter_c, ter_b, ter_b]))
self.assertFalse(cfg.contains([ter_b, ter_c, ter_a]))
self.assertFalse(cfg.contains([ter_b, ter_b, ter_c, ter_a, ter_a]))
