Re: [PATCH v7 3/3] git-jump: invoke emacs/emacsclient

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Fri, Nov 25 2022, Yoichi Nakayama via GitGitGadget wrote:

> From: Yoichi Nakayama <yoichi.nakayama@gmail.com>
>
> It works with GIT_EDITOR="emacs", "emacsclient" or "emacsclient -t"
>
> Signed-off-by: Yoichi Nakayama <yoichi.nakayama@gmail.com>
> ---
>  contrib/git-jump/git-jump | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/contrib/git-jump/git-jump b/contrib/git-jump/git-jump
> index cc97b0dcf02..eef9cda832f 100755
> --- a/contrib/git-jump/git-jump
> +++ b/contrib/git-jump/git-jump
> @@ -23,7 +23,22 @@ EOF
>  
>  open_editor() {
>  	editor=`git var GIT_EDITOR`
> -	eval "$editor -q \$1"
> +	case "$editor" in
> +	*emacs*)
> +		# Supported editor values are:
> +		# - emacs
> +		# - emacsclient
> +		# - emacsclient -t
> +		#
> +		# Wait for completion of the asynchronously executed process
> +		# to avoid race conditions in case of "emacsclient".
> +		eval "$editor --eval \"(let ((buf (compilation-start \\\"cat \$1\\\" 'grep-mode))) (pop-to-buffer buf) (select-frame-set-input-focus (selected-frame)) (while (get-buffer-process buf) (sleep-for 0.1)))\""
> +		;;
> +	*)
> +		# assume anything else is vi-compatible
> +		eval "$editor -q \$1"
> +		;;
> +	esac
>  }
>  
>  mode_diff() {

I'd really like to have some closer and smarter emacs integration like
this.

But I don't see why we need to run the grep ourselves, pipe it to a
temporary file, and then discover that we're using emacs, and --eval
code into it to switch to that buffer, and fake up a "M-x grep" command
with a compilation buffer to make it look like we ran M-x grep in the
first place.

Let's just ... run M-x grep earlier? Then we can skip all the earlier
steps.

I experimented with this a bit locally, and I didn't get the "switch to
buffer" semantics to work with this (but that's presumably easy, I'm
just rusty on my elisp APIs), but something in this direction seems much
better:
	
	diff --git a/contrib/git-jump/git-jump b/contrib/git-jump/git-jump
	index eef9cda832f..c932d7acd0f 100755
	--- a/contrib/git-jump/git-jump
	+++ b/contrib/git-jump/git-jump
	@@ -22,23 +22,7 @@ EOF
	 }
	 
	 open_editor() {
	-	editor=`git var GIT_EDITOR`
	-	case "$editor" in
	-	*emacs*)
	-		# Supported editor values are:
	-		# - emacs
	-		# - emacsclient
	-		# - emacsclient -t
	-		#
	-		# Wait for completion of the asynchronously executed process
	-		# to avoid race conditions in case of "emacsclient".
	-		eval "$editor --eval \"(let ((buf (compilation-start \\\"cat \$1\\\" 'grep-mode))) (pop-to-buffer buf) (select-frame-set-input-focus (selected-frame)) (while (get-buffer-process buf) (sleep-for 0.1)))\""
	-		;;
	-	*)
	-		# assume anything else is vi-compatible
	-		eval "$editor -q \$1"
	-		;;
	-	esac
	+	eval "$editor -q \$1"
	 }
	 
	 mode_diff() {
	@@ -83,11 +67,14 @@ mode_ws() {
	 }
	 
	 use_stdout=
	+use_magic=t
	 while test $# -gt 0; do
	 	case "$1" in
	 	--stdout)
	 		use_stdout=t
	-		shift
	+		;;
	+	--no-magic)
	+		use_magic=
	 		;;
	 	--*)
	 		usage >&2
	@@ -96,7 +83,8 @@ while test $# -gt 0; do
	 	*)
	 		break
	 		;;
	-	esac
	+	esac &&
	+	shift
	 done
	 if test $# -lt 1; then
	 	usage >&2
	@@ -105,6 +93,22 @@ fi
	 mode=$1; shift
	 type "mode_$mode" >/dev/null 2>&1 || { usage >&2; exit 1; }
	 
	+editor=`git var GIT_EDITOR`
	+if test "$use_magic" && test "$mode" = "grep"
	+then
	+	case "$editor" in
	+	*emacs*)
	+		set -x
	+		eval "$editor --eval \" \
	+			(grep \\\"git grep -H "$@"\\\") \
	+		\""
	+		exit
	+		;;
	+	*)
	+		;;
	+	esac
	+fi
	+
	 if test "$use_stdout" = "t"; then
	 	"mode_$mode" "$@"
	 	exit 0

I.e. if we're going to trust emacs to eval this code, and assume that
grep.el etc. works, let's just run the equivalent of M-x grep with our
'git grep' command.

This is already better in that "grep" understands that I searched for
"foo.*bar", so that's highlighted in the resulting buffer, just as with
normal "grep" commands.

This is missing the bit where we'd need to jump.grepCmd etc, so it's
incomplete.

I think this is all the prior art we'd need to invoke "git grep" the
right way from emacs's "grep":
https://github.com/eglaysher/find-things-fast/blob/master/find-things-fast.el#L246

B.t.w. I'd think the "--no-magic" here is something you'd want too. I
like this new behavior (sans the comments above), but presumably there's
people using emacs as their EDITOR who don't want to have this magic
behavior, having an opt-out would be neat.

I.e. if you have an existing customization intercepting these then this
will screw with that, but maybe that's OK...