Re: [PATCHv2 1/4] refs: add common refname_match_patterns()

From: Tom Grennan <tmgrennan@gmail.com>
Date: Feb 13, 2012, 17:27 UTC
Message-ID: <20120213172754.GG4903@tgrennan-laptop>
In-Reply-To: <4F3898F8.2000201@alum.mit.edu>

On Mon, Feb 13, 2012 at 06:00:40AM +0100, Michael Haggerty wrote:

Show 27 quoted lines

>On 02/11/2012 08:17 PM, Tom Grennan wrote:
>> Yes, I didn't explicitly state that the precedence is the order written
>> and in correctly described the first case. How about?
>> 
>> /**
>>  * Returns in highest to lowest precedence:
>>  *   1 with an empty patterns list
>>  *   0 if refname fnmatch()es any ^ prefaced pattern
>>  *   1 if refname fnmatch()es any other pattern
>>  *   0 otherwise
>>  */
>
>Much better; thanks.
>
>Please note that this choice of semantics limits its power.  For
>example, if the rule were instead (like with gitattributes(5)) "if more
>than one pattern matches a refname, a later pattern overrides an earlier
>pattern", then one could do things like
>
>    refs/remotes/*/* !refs/remotes/gitster/* refs/remotes/gitster/master
>
>to include specific references within a hierarchy that is otherwise
>excluded.
>
>However, since rev-list apparently uses a rule more like the one that
>you are proposing, it might be better to be consistent than to choose a
>different convention.

Hmm, I think it's important to have same respective result in each of these case's,

  $ git tag -l | grep v1.7.8.*
  $ git tag -l v1.7.8*

  $ git tag -l | grep -v .*-rc*
  $ git tag -l ^*-rc*

  $ git tag -l v1.7.8* | grep -v .*-rc*
  $ git tag -l v1.7.8* ^*-rc*
  $ git tag -l ^*-rc* v1.7.8*

What I propose is somewhat analogous to gitignore's double negative,
      *	An optional prefix !  which negates the pattern; any matching
	file excluded by a previous pattern will become included again. If
	a negated pattern matches, this will override lower precedence
	patterns sources.

I still prefer "^" to "!" b/c A) it doesn't cause the noted regressions; and B) doesn't need command quoting. I'd accept the counter proposals of --exclude or --with[out][-TYPE] but frankly, that's more code/documentation churn ("less code is always better"[TM]) and worse, more crap to type on the command line:

  $ git --with-tags v1.7.8* --without-tags '*-rc*' tag -l v1.7.8* 
or
  $ git tag -l --exclude '*-rc*' v1.7.8*
vs.
  $ git tag -l v1.7.8* ^*-rc*

-- 
TomG