def test_number():
int_pattern = r.seq(r.opt(r.alt(r.quote("+"), r.quote("-"))),
r.repeat(1, None, r.char_from("0123456789")))
num_pattern = r.seq(int_pattern,
r.opt(r.seq(r.quote("."),
r.opt(int_pattern))))
number = re.compile(num_pattern)
assert not number.fullmatch("foo")
assert not number.fullmatch("+")
assert number.fullmatch("0")
assert number.fullmatch("-42")
assert number.fullmatch("3.")
assert number.fullmatch("3.14")
def test_unlimited_repetition():
pattern = r.repeat(2, None, r.alt(r.quote("cat"), r.quote("dog")))
assert not re.fullmatch(pattern, 'cat')
assert re.fullmatch(pattern, 'catdog')
assert re.fullmatch(pattern, 'dogcatcat')
assert re.fullmatch(pattern, 'dogcatcatdogdogcat')
def test_match_alternative():
pattern = r.alt(r.quote("cat"), r.quote("dog"))
assert not re.fullmatch(pattern, 'foo')
assert re.fullmatch(pattern, 'cat')
assert re.fullmatch(pattern, 'dog')
assert not re.fullmatch(pattern, 'catdog')
def test_multiple_alternatives():
assert r.alt("foo", "bar", "baz") == "(foo|bar|baz)"
def test_single_alternative():
assert r.alt("foo") == "(foo)"
def test_empty_alternative():
assert r.alt() == "()"