Re: packages: [PoC] Expand range of objects 'add-input-label' can label

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

elaexuotee@wilsonb.com skribis:

> From 3b8e7fa8fbd58e7e164e3730c708419f612b8549 Mon Sep 17 00:00:00 2001
> From: "B. Wilson" <elaexuotee@wilsonb.com>
> Date: Sun, 16 Jan 2022 23:54:51 +0900
> Subject: [PATCH 1/2] packages: Expand range of objects 'add-input-label' can
>  label
> To: guix-patches@gnu.org
>
> * guix/packages.scm (%auxiliary-files-subpath-dir): New variable.
> (add-input-label): Support labels from the name property of
> objects that have one.  Also, name auxiliary files from their
> subpath.

[...]

>  (define (add-input-label input)
>    "Add an input label to INPUT."
>    (match input
> @@ -576,7 +581,24 @@ (define (add-input-label input)
>       (list (package-name package) package))
>      (((? package? package) output)                ;XXX: ugly?
>       (list (package-name package) package output))
> -    ((? gexp-input?)       ;XXX: misplaced because 'native?' field is ignored?
> +    ((? local-file? local-file)
> +     (list (local-file-name local-file) local-file))
> +    ((? plain-file? plain-file)
> +     (list (plain-file-name plain-file) plain-file))
> +    ((? computed-file? computed-file)
> +     (list (computed-file-name computed-file) computed-file))
> +    ((? program-file? program-file)
> +     (list (program-file-name program-file) program-file))
> +    ((? scheme-file? scheme-file)
> +     (list (scheme-file-name scheme-file) scheme-file))
> +    ((? string? path)
> +     (let* ((regex (string-append %auxiliary-files-subdir-path "/(.*)"))
> +            (match (string-match regex input)))
> +       `(,(if match
> +               (match:substring match 1)
> +               "_")
> +          ,input)))
> +    ((? gexp-input?)      ;XXX: misplaced because 'native?' field is ignored?

I can see why it’s tempting to add more labels, but the medium-term goal
is to remove labels altogether since there are other mechanisms to fill
the same role:

  https://guix.gnu.org/en/blog/2021/the-big-change/

I would keep things as they are and instead encourage you to use gexps
when you need to refer to file-like objects in packages.

We’re still fine-tuning the idioms, so feel free to ask if you don’t see
how to achieve what you want.

HTH!

Ludo’.