def test_to_final_state(self):
""" Test transformation to final state """
state = State("#STARTTOFINAL#")
symbol_e = Symbol("e")
symbol_i = Symbol("i")
symbol_z = StackSymbol("Z")
pda = PDA(states={state},
input_symbols={symbol_i, symbol_e},
stack_alphabet={symbol_z},
start_state=state,
start_stack_symbol=symbol_z)
pda.add_transition(state, symbol_i, symbol_z, state,
[symbol_z, symbol_z])
pda.add_transition(state, symbol_e, symbol_z, state, [])
new_pda = pda.to_final_state()
self.assertEqual(len(new_pda.states), 3)
self.assertEqual(len(new_pda.input_symbols), 2)
self.assertEqual(len(new_pda.stack_symbols), 2)
self.assertEqual(new_pda.get_number_transitions(), 4)
self.assertEqual(len(new_pda.final_states), 1)
def test_pda_paper(self):
""" Code in the paper """
pda = PDA()
pda.add_transitions([("q0", "0", "Z0", "q1", ("Z1", "Z0")),
("q1", "1", "Z1", "q2", []),
("q0", "epsilon", "Z1", "q2", [])])
pda.set_start_state("q0")
pda.set_start_stack_symbol("Z0")
pda.add_final_state("q2")
pda_final_state = pda.to_final_state()
cfg = pda.to_empty_stack().to_cfg()
self.assertTrue(cfg.contains(["0", "1"]))
pda_networkx = PDA.from_networkx(pda.to_networkx())
self.assertEqual(pda.states, pda_networkx.states)
self.assertEqual(pda.start_state, pda_networkx.start_state)
self.assertEqual(pda.final_states, pda_networkx.final_states)
self.assertEqual(pda.input_symbols, pda_networkx.input_symbols)
self.assertEqual(pda.stack_symbols, pda_networkx.stack_symbols)
cfg = pda_networkx.to_empty_stack().to_cfg()
pda_networkx.write_as_dot("pda.dot")
self.assertTrue(cfg.contains(["0", "1"]))
self.assertTrue(path.exists("pda.dot"))
