core :: Char :: is_digit
assert '0'.is_digit == true assert '9'.is_digit == true assert 'a'.is_digit == false
# Is self a digit? (from '0' to '9') # # assert '0'.is_digit == true # assert '9'.is_digit == true # assert 'a'.is_digit == false fun is_digit : Bool do return self >= '0' and self <= '9' end