def test_example62(self):
""" Example from the book """
state0 = State("q0")
state1 = State("q1")
state2 = State("q2")
s_zero = Symbol("0")
s_one = Symbol("1")
ss_zero = StackSymbol("0")
ss_one = StackSymbol("1")
ss_z0 = StackSymbol("Z0")
pda = PDA(states={state0, state1, state2},
input_symbols={s_zero, s_one},
stack_alphabet={ss_zero, ss_one, ss_z0},
start_state=state0,
start_stack_symbol=ss_z0,
final_states={state2})
self.assertEqual(len(pda.states), 3)
self.assertEqual(len(pda.input_symbols), 2)
self.assertEqual(len(pda.stack_symbols), 3)
self.assertEqual(pda.get_number_transitions(), 0)
pda.add_transition(state0, s_zero, ss_z0, state0, [ss_zero, ss_z0])
pda.add_transition(state0, s_one, ss_z0, state0, [ss_one, ss_z0])
pda.add_transition(state0, s_zero, ss_zero, state0, [ss_zero, ss_zero])
pda.add_transition(state0, s_one, ss_one, state0, [ss_zero, ss_one])
pda.add_transition(state0, s_one, ss_zero, state0, [ss_one, ss_zero])
pda.add_transition(state0, s_one, ss_one, state0, [ss_one, ss_one])
pda.add_transition(state0, Epsilon(), ss_z0, state1, [ss_z0])
pda.add_transition(state0, Epsilon(), ss_zero, state1, [ss_zero])
pda.add_transition(state0, Epsilon(), ss_one, state1, [ss_one])
pda.add_transition(state1, s_zero, ss_zero, state1, [])
pda.add_transition(state1, s_one, ss_one, state1, [])
pda.add_transition(state1, Epsilon(), ss_z0, state2, [ss_z0])
self.assertEqual(pda.get_number_transitions(), 12)
t_zero = Terminal("0")
t_one = Terminal("1")
cfg = pda.to_empty_stack().to_cfg()
self.assertTrue(cfg.contains([]))
self.assertTrue(cfg.contains([t_zero, t_zero]))
self.assertTrue(cfg.contains([t_zero, t_one, t_one, t_zero]))
self.assertFalse(cfg.contains([t_zero]))
self.assertFalse(cfg.contains([t_zero, t_one, t_zero]))
def test_creation(self):
""" Test of creation """
pda = PDA()
self.assertIsNotNone(pda)
self.assertEqual(len(pda.states), 0)
self.assertEqual(len(pda.final_states), 0)
self.assertEqual(len(pda.input_symbols), 0)
self.assertEqual(len(pda.stack_symbols), 0)
pda = PDA(start_state=State("A"))
self.assertIsNotNone(pda)
self.assertEqual(len(pda.states), 1)
self.assertEqual(len(pda.stack_symbols), 0)
self.assertEqual(len(pda.final_states), 0)
pda = PDA(final_states={
State("A"), State("A"),
State("B"), Symbol("B")
})
self.assertIsNotNone(pda)
self.assertEqual(len(pda.states), 3)
self.assertEqual(len(pda.input_symbols), 0)
self.assertEqual(len(pda.stack_symbols), 0)
self.assertEqual(len(pda.final_states), 3)
pda = PDA(input_symbols={
Symbol("A"), Symbol("B"),
Symbol("A"), State("A")
})
self.assertIsNotNone(pda)
self.assertEqual(len(pda.states), 0)
self.assertEqual(len(pda.input_symbols), 3)
self.assertEqual(len(pda.stack_symbols), 0)
self.assertEqual(len(pda.final_states), 0)
pda = PDA(start_stack_symbol=StackSymbol("A"))
self.assertIsNotNone(pda)
self.assertEqual(len(pda.input_symbols), 0)
self.assertEqual(len(pda.states), 0)
self.assertEqual(len(pda.stack_symbols), 1)
self.assertEqual(len(pda.final_states), 0)
pda = PDA(stack_alphabet={
StackSymbol("A"),
StackSymbol("A"),
StackSymbol("B")
})
self.assertIsNotNone(pda)
self.assertEqual(len(pda.states), 0)
self.assertEqual(len(pda.input_symbols), 0)
self.assertEqual(len(pda.stack_symbols), 2)
self.assertEqual(len(pda.final_states), 0)
pda = PDA(input_symbols={Epsilon()})
self.assertIsNotNone(pda)
self.assertEqual(len(pda.states), 0)
self.assertEqual(len(pda.input_symbols), 1)
self.assertEqual(len(pda.stack_symbols), 0)
self.assertEqual(pda.get_number_transitions(), 0)
self.assertEqual(len(pda.final_states), 0)
def test_transition(self):
""" Tests the creation of transition """
pda = PDA()
pda.add_transition(
State("from"), Symbol("input symbol"), StackSymbol("stack symbol"),
State("to"), [StackSymbol("A"), StackSymbol("B")])
self.assertEqual(len(pda.states), 2)
self.assertEqual(len(pda.input_symbols), 1)
self.assertEqual(len(pda.stack_symbols), 3)
self.assertEqual(pda.get_number_transitions(), 1)
pda.add_transition(
State("from"), Epsilon(), StackSymbol("stack symbol"), State("to"),
[StackSymbol("A"), StackSymbol("B")])
self.assertEqual(len(pda.states), 2)
self.assertEqual(len(pda.input_symbols), 1)
self.assertEqual(len(pda.stack_symbols), 3)
self.assertEqual(pda.get_number_transitions(), 2)