def test_null_range():
r = Range(1, "downto", 4)
assert r.left == 1
assert r.direction == "downto"
assert r.right == 4
assert len(r) == 0
assert list(r) == []
assert list(reversed(r)) == []
with pytest.raises(IndexError):
r[0]
assert 2 not in r
with pytest.raises(ValueError):
r.index(4)
assert r.count(4) == 0
def test_to_range():
r = Range(1, "to", 8)
assert r.left == 1
assert r.direction == "to"
assert r.right == 8
assert len(r) == 8
assert list(r) == [1, 2, 3, 4, 5, 6, 7, 8]
assert list(reversed(r)) == [8, 7, 6, 5, 4, 3, 2, 1]
assert r[0] == 1
assert r[7] == 8
with pytest.raises(IndexError):
r[8]
assert r[3:7] == Range(4, "to", 7)
assert 8 in r
assert 10 not in r
assert r.index(7) == 6
with pytest.raises(ValueError):
r.index(9)
assert r.count(4) == 1
assert r.count(10) == 0
def test_downto_range():
r = Range(4, "downto", -3)
assert r.left == 4
assert r.direction == "downto"
assert r.right == -3
assert len(r) == 8
assert list(r) == [4, 3, 2, 1, 0, -1, -2, -3]
assert list(reversed(r)) == [-3, -2, -1, 0, 1, 2, 3, 4]
assert r[0] == 4
assert r[7] == -3
with pytest.raises(IndexError):
r[8]
assert r[3:7] == Range(1, "downto", -2)
assert 0 in r
assert 10 not in r
assert r.index(2) == 2
with pytest.raises(ValueError):
r.index(9)
assert r.count(4) == 1
assert r.count(10) == 0