Re: [PATCH] Add a simple option parser.

On Thu, Oct 04, 2007 at 02:57:58PM +0000, Kristian Høgsberg wrote:

On Thu, 2007-10-04 at 01:11 +0200, Pierre Habouzit wrote:

quoted

On Wed, Oct 03, 2007 at 09:45:01PM +0000, Kristian Høgsberg wrote:

quoted

The option parser takes argc, argv, an array of struct option
and a usage string.  Each of the struct option elements in the array
describes a valid option, its type and a pointer to the location where the
value is written.  The entry point is parse_options(), which scans through
the given argv, and matches each option there against the list of valid
options.  During the scan, argv is rewritten to only contain the
non-option command line arguments and the number of these is returned.

  if we are going in that direction (and I believe it's a good one), we
should be sure that the model fits with other commands as well. And as I
said on IRC, I believe the most "horrible" (as in complex) option parser
in git is the one from git-grep.

  A migration of git-grep on that API should be tried first. If this
works well enough, I believe that the rest of the git commands will be
migrated easily enough. (with maybe small addition to parse-option.[hc]
but the hardcore things should have been met with git-grep already I
think).

I'm not sure - we can go with the current proposal and add new options
types and probably the callback option type I suggested as we go.  I
don't want to block builtin-commit on figuring out what the perfect
option parser should look like and what I sent out earlier work for
commit.  I think the way you handled the strbuf rewrites worked pretty
well; extending and rewriting the API as you put it to use in more and
more places.  We can do the same thing with parse_options().

  Of course we can do that, or junio said that some people talked about
popt some time ago. I understand that you don't want to block the
git-commit work, but doing things right from the beginning is often a
big win on the long term.

  I don't know popt, and I don't know if it has sufficient expressivity.
For sure I don't like getopt_long APIs at all, so if popt is as
cumbersome, rolling our own based on the current parse_options you
propose is probably a good choice.

-- 
·O·  Pierre Habouzit
··O                                                madcoder@debian.org
OOO                                                http://www.madism.org