Re: [PATCH 2/4] completion: introduce __git_find_subcommand

From: "Rubén Justo" <rjusto@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: Git List <git@vger.kernel.org>
Subject: Re: [PATCH 2/4] completion: introduce __git_find_subcommand
Date: Sat, 27 Jan 2024 14:20:21 +0100	[thread overview]
Message-ID: <c49d1df1-13ca-449e-a826-94be84953ece@gmail.com> (raw)
In-Reply-To: <xmqqh6j0ngsb.fsf@gitster.g>

On 26-ene-2024 09:30:44, Junio C Hamano wrote:
> Rubén Justo <rjusto@gmail.com> writes:
> 
> > Let's have a function to get the current subcommand when completing
> > commands that follow the syntax:
> >
> >     git <command> <subcommand>
> >
> > As a convenience, let's allow an optional "default subcommand" to be
> > returned if none is found.
> >
> > Signed-off-by: Rubén Justo <rjusto@gmail.com>
> > ---
> >  contrib/completion/git-completion.bash | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> >
> > diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
> > index 916e137021..5f2e904b56 100644
> > --- a/contrib/completion/git-completion.bash
> > +++ b/contrib/completion/git-completion.bash
> > @@ -575,6 +575,26 @@ __gitcomp_subcommand ()
> >  	fi
> >  }
> >  
> > +# Find the current subcommand for commands that follow the syntax:
> > +#
> > +#    git <command> <subcommand>
> > +#
> > +# 1: List of possible subcommands.
> > +# 2: Optional subcommand to return when none is found.
> > +__git_find_subcommand ()
> > +{
> > +	local subcommand subcommands="$1" default_subcommand="$2"
> 
> Are the callers expected to form "$1" by concatenating known tokens
> with a space?
> 
> I am just wondering if we can avoid looping, e.g.
> 
> 	local nextword=${words[__git_cmd_idx+1]}
> 	case " $subcommands " in
> 	*" $nextword "*)
> 		echo "$nextword"
> 		return
> 		;;
> 	esac
> 

I like the idea; and it works:

     $ words=("a" "b"); __git_cmd_idx=0; __git_find_subcommand "a b" "test"
     b

     $ : simulate that the user moves the cursor backwards
     $ words=("a" "" "b"); __git_cmd_idx=0; __git_find_subcommand "a b" "test"
     test

     $ : simulate that the user moves the cursor backwards
     $ words=("a" " " "b"); __git_cmd_idx=0; __git_find_subcommand "a b" "test"
     test

But functions like __git_find_on_cmdline or __git-find_last_on_cmdline
are already iterating.  I feel we should keep the loop.

Thank you.