On Sun, Dec 10, 2017 at 3:39 PM, Jeff King <p...@peff.net> wrote: > On Sun, Dec 10, 2017 at 09:31:18AM -0500, Jeff King wrote: > >> On Sat, Dec 09, 2017 at 09:40:07PM +0100, Christian Couder wrote: >> >> > The changes compared to v2 are: >> > >> > - s/_val/_arg/ in the name of the functions >> > - s/val/arg/ in the name of the third argument of the functions >> > - works with NULL as third argument of the functions >> >> This whole series looks OK to me, but this third point made me wonder: >> what would be the use of allowing NULL for the "arg" parameter? >> >> I didn't see any use of this in the series, and I'm having trouble >> figuring out how it would be useful. E.g., if I do: >> >> if (skip_to_optional_arg(arg, "--foo", NULL)) >> ... >> >> what can I do in "..."? I know we matched _some_ type of "--foo", but I >> cannot know whether it was "--foo" or "--foo=bar", nor what "bar" is. It >> could only be used by some kind of vague validator to say "well, at >> least this looks like an option that I _could_ parse if I wanted to". >> >> So I guess I don't mind it, as it does the most reasonable thing it can >> when passed NULL, but I would be surprised if we ever actually exercise >> the code path. > > And of course as soon as I sent this, I went back and double-checked. > And indeed I totally missed this call: > > + else if (starts_with(arg, "-B") || > + skip_to_optional_arg(arg, "--break-rewrites", NULL)) { > if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
Yeah, calls like this were discussed in: https://public-inbox.org/git/xmqqh8t6o9me....@gitster.mtv.corp.google.com/ > So that's kind-of weird, because we are parsing "-B", etc, and then > expecting it to be _reparsed_ by diff_scoreopt_parse. So the two > callsites must always match. IMHO this ought to do either: > > - we should just ask diff_scoreopt_parser to tell us if this was a > valid option that it understood > > or > > - parse up to the "=", and then ask the scoreopt parser to parse the > remainder. This would require us passing 'B'/'C'/'M' to the > function ourselves, I think that's a better pattern. It means we > could reuse the parser for things like config values if we wanted to > (our current diff.renames is a bool, but it would not be > unreasonable for it to take a score). > > None of that is a mess of your creation, though, so I'm OK punting on it > for now. Yeah, this could be part of the #leftoverbits.