Re: Texinfo in descriptions?

[ludo@gnu.org (Ludovic Courtès)]

Mathieu Lirzin <mthl@openmailbox.org> skribis:

>> Any performance figures?  For instance, time of ‘guix package -s’ before
>> and after?
>
> With the updated patch I have obtained the following results for command
>
>   time ./pre-inst-env guix package -s e
>
> - without patch:
> real	0m25.381s
> user	0m8.740s
> sys	0m0.184s
>
> - with patch:
> real	0m24.556s
> user	0m10.448s
> sys	0m0.220s

Sounds good.

[...]

> +(define (package-description-string package)
> +  "Return a plain-text representation of PACKAGE description field."
> +  (and=> (package-description package)
> +         (compose stexi->plain-text texi-fragment->stexi P_)))
> +
>  (define (string->recutils str)
>    "Return a version of STR where newlines have been replaced by newlines
>  followed by \"+ \", which makes for a valid multi-line field value in the
> @@ -786,10 +795,8 @@ followed by \"+ \", which makes for a valid multi-line field value in the
>    "Write to PORT a `recutils' record of package P, arranging to fit within
>  WIDTH columns."
>    (define (description->recutils str)
> -    (let ((str (P_ str)))
> -      (string->recutils
> -       (fill-paragraph str width
> -                       (string-length "description: ")))))
> +    (string->recutils
> +     (fill-paragraph str width (string-length "description: "))))

One last thing (I swear!).

AFAICS ‘stexi->plain-text’ already does paragraph filling, so the call
above is redundant (and could break the rendering.)

However, the width of the rendered text is fixed, unlike what
‘string->recutils’ did so far.  To work around that, we’ll have to
monkey-patch the ‘wrap*’ procedure of (texinfo plain-text), along these
lines:

  (define %text-width
    (make-parameter (or (and=> (getenv "WIDTH") string->number)
                        80)))

  (set! (@@ (texinfo plain-text) wrap*)
        (lambda strings
          ... #:line-width (%text-width) ...))

and then in ‘package->recutils’, we need to ‘parameterize’ that.

We need a similar hack for #:initial-indent, that would allow us to
mimic the 3rd argument of ‘fill-paragraph’.

Could you try it?

> From 3c69e9f79f4d5bd5a75d4c083769caf32c1a63ec Mon Sep 17 00:00:00 2001
> From: Mathieu Lirzin <mthl@openmailbox.org>
> Date: Thu, 27 Aug 2015 17:51:11 +0200
> Subject: [PATCH] website: packages: Support Texinfo's markup.
>
> * website/www/packages.scm (package->sxml): Adapt to new Texinfo's
>   markup in package description.

LGTM!

Thanks,
Ludo’.