From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 30 Jul 2013 22:28:52 GMT
Subject: Re: [PATCH] tag: Use OPT_BOOL instead of OPT_BOOLEAN to allow one action multiple times
Message-ID: <7vfvuvvg0r.fsf@alter.siamese.dyndns.org>
In-Reply-To: <51F83010.2060804@googlemail.com>

Stefan Beller <stefanbeller@googlemail.com> writes:

> Here is just another idea: 
> 	if (cmdmode == 'v')
> This may be hard to read, (What is 'v'? I cannot remember 
> all the alphabet ;)) So maybe we could have an enum instead of
> the last parameter? 
> OPT_CMDMODE( short, long, variable, description, enum)

I actually was thinking about going totally in the opposite
direction.

People who grew up with the old Unix tradition getopt(3) are used to
code like this:

        while ((opt = getopt(ac, av, "abcde")) != -1) {
                switch (opt) {
                case 'a': perform_a(); break;
                case 'b': perform_b(); break;
                ...
                }
        }

In other words, the "enum" is most convenient if it matches the
"short" option, so instead of having to repeat ourselves over and
over, like I did in that illustration patch for builtin/tag.c, e.g.

		OPT_CMDMODE('d', "delete", &cmdmode, N_("delete tags"), 'd'),
		OPT_CMDMODE('v', "verify", &cmdmode, N_("verify tags"), 'v'),

we could just do

#define OPT_CMDMODE(s, l, v, h) \
    { OPTION_CMDMODE, (s), (l), (v), NULL, \
      (h), PARSE_OPT_NOARG|PARSE_OPT_NONEG, NULL, (s) }