def test_automaton_from_ε_grammar(self):
# fig 5.14 pag 147
A = Automaton.from_grammar(Grammar.from_string("""
S -> A
S -> a B
A -> a A
A -> ε
B -> b B
B -> b
"""))
s = "Automaton(N={A, B, S, ◇}, T={a, b}, transitions=(S-ε->A, S-a->B, A-a->A, A-ε->◇, B-b->B, B-b->◇), F={◇}, q0=S)"
self.assertEqual(s, str(A))
def test_automaton_δ(self):
# fig 5.6, pag 142
states = Automaton.from_grammar(Grammar.from_string("""
S -> a A
S -> a B
A -> b B
A -> b C
B -> c A
B -> c C
C -> a
""")).δ('S', 'a')
self.assertEqual({'A', 'B'}, states)
def test_automaton_from_grammar(self):
# fig 5.6, pag 142
A = Automaton.from_grammar(Grammar.from_string("""
S -> a A
S -> a B
A -> b B
A -> b C
B -> c A
B -> c C
C -> a
"""))
s = 'Automaton(N={A, B, C, S, ◇}, T={a, b, c}, transitions=(S-a->A, S-a->B, A-b->B, A-b->C, B-c->A, B-c->C, C-a->◇), F={◇}, q0=S)'
self.assertEqual(s, str(A))
def test_automaton_from_string(self):
# HMU, fig 4.8, pag 147
A = Automaton.from_string("""
A, 0, B
A, 1, F
B, 0, G
B, 1, C
C, 1, C
D, 0, C
D, 1, G
E, 0, H
E, 1, F
F, 0, C
F, 1, G
G, 0, G
H, 0, G
H, 1, C
""", {'C'})
s = 'Automaton(N={A, B, C, D, E, F, G, H}, T={0, 1}, transitions=(A-0->B, A-1->F, B-0->G, B-1->C, C-1->C, D-0->C, D-1->G, E-0->H, E-1->F, F-0->C, F-1->G, G-0->G, H-0->G, H-1->C), F={C}, q0=A)'
self.assertEqual(s, str(A))
def test_automaton_FN(self):
with self.assertRaisesRegex(ValueError, r'states {C} in F are not states'):
Automaton({'A', 'B'}, {'b', 'c'}, tuple(), 'A', {'B', 'C'})
def test_automaton_q0N(self):
with self.assertRaisesRegex(ValueError, r'\(X\) is not a state'):
Automaton({'A', 'B'}, {'b', 'c'}, tuple(), 'X', set())
def test_automaton_overlapTN(self):
with self.assertRaisesRegex(ValueError, "but have {B} in common"):
Automaton({'A', 'B'}, {'B', 'C'}, tuple(), set(), 'A')
def test_automaton_from_grammar_fail2b(self):
with self.assertRaisesRegex(ValueError, 'not of the aB form'):
Automaton.from_grammar(Grammar.from_string('S -> B B'))
def test_automaton_from_grammar_fail3(self):
with self.assertRaisesRegex(ValueError, 'has more than two symbols'):
Automaton.from_grammar(Grammar.from_string('S -> a b c'))