Classify text without allocating

isascii() accepts only ASCII characters, including controls and NUL. isspace() checks for nonempty text containing only Unicode whitespace:

def main() -> Result[(), IoError]:
    print("hello".isascii())?
    print("é".isascii())?
    print("".isascii())?
    print(" \t\n".isspace())?
    print(" x ".isspace())?
    print("".isspace())?
    Ok(())

True
False
True
True
False
False

Both queries borrow their receiver and allocate nothing. Whitespace means the same Unicode White_Space characters removed by strip; NUL and zero-width space do not count.