Re: Fwd: Possibly nicer pathspec syntax?

[Mike Hommey <mh@glandium.org>]

On Tue, Feb 07, 2017 at 05:48:26PM -0800, Linus Torvalds wrote:
> 
> 
> On Tue, 7 Feb 2017, Linus Torvalds wrote:
> > 
> > [ Clarification from original message, since Junio asked: I didn't
> >   actually want the semantics of '.' at all, since in a subdirectory it
> >   limits to the current subdirectory. So I'd suggest that in the absence
> >   of any positive pattern, there is simply no filtering at all, so
> >   whenever I say '.' as a pattern, I really meant ":(top)." which is
> >   even more of a cumbersom syntax that the current model really
> >   encourages. Crazy. Since I tend to always work in the top directory,
> >   the two are the same for me ]
> 
> So here's an RFC patch, and I'm quoting the above part of my thinking 
> because it's what the patch does, but it turns out that it's probably not 
> what we want, and I suspect the "." behavior (as opposed to "no filtering 
> at all") is actually better.
> 
> Now _I_ don't much care, since I only work from the top level, but without 
> the "." behavior, you get into an odd situation that the negative match 
> will be relative to the current directory, but then the positive matches 
> will be everywhere else. 
> 
> Obviously, a negative match that has "top" set would change that logic. So 
> this patch is purely a request for further discussion.
> 
> When I wrote the patch, I actually also removed the now stale entries from 
> the 'po' files, but I'm not including that part here because it just 
> distracts from the meat of it all. So this diff was actually generated 
> with the new syntax:
> 
> 	git diff -p --stat -- :^po/
> 
> and the only thing even remotely subtle here is that it changes our ctype 
> array to make '^' be both a regex and a pathspec magic character.
> 
> Everything else should be pretty darn obvious.
> 
> The code *could* just track all the 'relative to top or not' bits in the 
> exclusion pattern, and then use whatever top-ness the exclusion patterns 
> have (and maybe fall back to the old warning if it had a mixture of 
> exclusionary patterns). I'll happily change it to act that way if people 
> think that makes sense.
> 
> Comments?

It seems to me that `git diff` and `git diff -- :^stuff` should have the
same output if there aren't changes in stuff, and `git diff` does the
same as `git diff -- :/` if you are in a subdirectory, not the same as
`git diff .`.

As such, the default positive match should be ':/' (which is shorter and
less cumbersome than ':(top)', btw)

Mike