Determine which options we can set, which ones are boolean, and which ones are repeatable.

    All set items are option long names.

    :param str doc: Docstring from docoptcfg().
    :param iter argv: CLI arguments from docoptcfg().
    :param iter ignore: Options to ignore from docoptcfg().
    :param bool options_first: docopt argument from docoptcfg().

    :return: Settable options, boolean options, repeatable options, and short to long option name mapping.
    :rtype: tuple

def settable_options(doc, argv, ignore, options_first):
    """Determine which options we can set, which ones are boolean, and which ones are repeatable.

    All set items are option long names.

    :param str doc: Docstring from docoptcfg().
    :param iter argv: CLI arguments from docoptcfg().
    :param iter ignore: Options to ignore from docoptcfg().
    :param bool options_first: docopt argument from docoptcfg().

    :return: Settable options, boolean options, repeatable options, and short to long option name mapping.
    :rtype: tuple
    """
    settable, booleans, repeatable, short_map = set(), set(), set(), dict()

    # Determine which options are settable by docoptcfg and which ones are flags/booleans.
    options = docopt.parse_defaults(doc)
    short_map.update((o.short, o.long) for o in options)
    parsed_argv = docopt.parse_argv(docopt.TokenStream(argv, docopt.DocoptExit), list(options), options_first)
    overridden = [o.long for o in parsed_argv if hasattr(o, 'long')]
    for option in options:
        if option.long in overridden or (option.long in ignore or option.short in ignore):
            continue
        if option.argcount == 0:
            booleans.add(option.long)
        settable.add(option.long)

    # Determine which options are repeatable.
    if settable and '...' in doc:
        pattern = docopt.parse_pattern(docopt.formal_usage(docopt.DocoptExit.usage), options)
        for option in pattern.fix().flat():
            if not hasattr(option, 'long'):
                continue  # Positional argument or sub-command.
            if getattr(option, 'long') not in settable:
                continue  # Don't care about this if we can't set it.
            if getattr(option, 'long') in booleans and getattr(option, 'value') == 0:
                repeatable.add(getattr(option, 'long'))
            elif hasattr(getattr(option, 'value'), '__iter__'):
                repeatable.add(getattr(option, 'long'))

    return settable, booleans, repeatable, short_map