Re: feature request: excluding files/paths from "git grep"

On Sun, Mar 01, 2015 at 03:22:11PM -0800, Junio C Hamano wrote:

Trevor Saunders [off-list ref] writes:

quoted

quoted

...  For these "per-invocation" differences, attributes
to declare permenent/inherent nature of the contents is much less
suited than per-invocation inclusion/exclusion mechanism based on
pathspecs, I would think.

I think that makes some amount of sense, however typing stuff like
--exclude=ChangeLog all the time is not terribly easy on the hands.
Would it make sense to instead add a config variable grep.exclude?

I do not think it makes much more sense for at least three reasons.
for one thing, It still goes against "per-invocation" nature of what
is being done.  Your "for this invocation I do not want ChangeLog"
does not have to be limited to 'grep'.  And also "I end up having to
give these pathspecs all the time" is not limited to negative ones.

I think what is somewhat special about grep is that I want to ignore a
set of paths such a large majority of the time that I really want to
change the default.  I could see someone wanting to do the same thing
for diff or log maybe, and so adding diff.exclude, but personally I
don't have a use for it.

We have magic pathspecs, like "This pattern is used to match the
string case-insensitively", "This pattern specifies that the path
should *not* match it", etc.  How about adding a new feature that
lets you say "This is a short hand to giving these pathspecs" and
call that "pathspec macro"?

If you get tired to keep having to type

    $ git log -- Documentation/ ':!Documentation/technical/'

every time you want to check the end-user facing documentation
pages, you could for example say (I am using a made-up 'macro'
pathspec magic that is introduced by ':*' followed by a <macro
name>):

    $ git log -- ':*userdoc'

and the same macro specification could be used for all the other
things that take pathspecs (grep, add, diff, etc.).

I can certainly see use cases for that, say
git log -- :!t/ :!foo/tests/ :!bar/testsuite/
to see what non test changes have happened in a project that doesn't
have a standardized name for test directories.

You could then have something like this to define your own "nolog"
macro:

    [pathspecMacro]
        nolog = ':!ChangeLog' ':!ChangeLog.*'

to shorten your invocation of "grep" by appending it when you want
to exclude some files, i.e.

    $ git grep -e pattern -- \*.c ':*nolog'

and the same pathspec macro can be used in other places, not just
"grep".  Wouldn't it make more sense?

I think they solve somewhat different problems, but maybe my problem is
so specialized I should just have a wrapper around grep that changes
defaults.

Trev