Re: [PATCH 2/2] emacs: Add interface for comparing generations.

[ludo@gnu.org (Ludovic Courtès)]

Alex Kost <alezost@gmail.com> skribis:

> In short, now (with this patch) after marking 2 generations (by pressing
> "m" in a “generation-list” buffer), you can perform diff/ediff on
> generation packages or manifests.  Thanks to Ludovic for the idea.

I just tried it, and I like it!

There are cases where the output of ‘=’ is slightly confusing: the
buffers being compared don’t include the directory name of the packages,
so, when packages have been upgraded (different directory names, but
same version), it just says “no differences.”

Perhaps the fix would be to add the directory names in the buffers being
diffed, in a format similar to that of ‘guix package -I’?

I have another case where C-u = shows that the only difference is the
addition of one package, but = shows a diff with only minuses, as if
everything had been removed.  Any idea what could be wrong?

> +++ b/doc/emacs.texi
> @@ -239,6 +239,21 @@ Mark the current generation for deletion (with prefix, mark all
>  generations).
>  @item x
>  Execute actions on the marked generations---i.e., delete generations.
> +@item e
> +Run Ediff (@pxref{Top,,, ediff, Ediff}) on package outputs installed in
> +the 2 marked generations.  With prefix argument, run Ediff on manifests
> +of the marked generations.
> +@item D
> +@itemx =
> +Run Diff (@pxref{Diff Mode,,, emacs, The Emacs Editor}) on package
> +outputs installed in the 2 marked generations.  With prefix argument,
> +run Diff on manifests of the marked generations.
> +@item +
> +List package outputs added to the latest marked generation comparing
> +with another marked generation.
> +@item -
> +List package outputs removed from the latest marked generation comparing
> +with another marked generation.

Likewise, ‘u’ (for ‘upgraded’) could be added (possibly in a future
patch.)

Also, s/The Emacs Editor/GNU Emacs Manual/, which is the real title of
the Emacs manual as it appears in the texi source.

Thanks,
Ludo’.