def parse_and_append(cls, string, index, match):
    """Utility function which wraps a call to parse_from.

    Call parse_from on the specified class, append the new instance to
    the match list, and return the original return value of parse_from.
    This can be used in complex parse_from implementations to avoid
    writing repetitive list append statements for each parsed child.
    """
    instance, index = cls.parse_from(string, index)
    match.append(instance)
    return instance, index