def test_bug_28():
# This is (ab*)* and it caused some defects.
abstar = FSM(
alphabet = {'a', 'b'},
states = {0, 1},
initial = 0,
finals = {1},
map = {
0: {'a': 1},
1: {'b': 1}
}
)
assert abstar.accepts("a")
assert not abstar.accepts("b")
assert abstar.accepts("ab")
assert abstar.accepts("abb")
abstarstar = abstar.star()
assert abstarstar.accepts("a")
assert not abstarstar.accepts("b")
assert abstarstar.accepts("ab")
assert not abstar.star().accepts("bb")
def test_oblivion_crawl(a):
# When crawling a new FSM, we should avoid generating an oblivion state.
# `abc` has no oblivion state... all the results should not as well!
abc = FSM(
alphabet = {"a", "b", "c"},
states = {0, 1, 2, 3},
initial = 0,
finals = {3},
map = {
0 : {"a" : 1},
1 : {"b" : 2},
2 : {"c" : 3},
}
)
assert len((abc + abc).states) == 7
assert len(abc.star().states) == 3
assert len((abc * 3).states) == 10
assert len(reversed(abc).states) == 4
assert len((abc | abc).states) == 4
assert len((abc & abc).states) == 4
assert len((abc ^ abc).states) == 1
assert len((abc - abc).states) == 1
