def is_vowel(char: str) -> bool:
    """
    Checks if the character is an Irish vowel (aeiouáéíóú).

    :param char: the character to check
    :return: true if the input is a single character, and is an Irish vowel
    """
    vowels = "aeiouáéíóú"
    return len(char) == 1 and char.lower()[0] in vowels