Re: guile and i10n

[Nicolas Sceaux]

Le 31 déc. 08 à 19:02, Han-Wen Nienhuys a écrit :

> Hi,
>
> I think GUILE (like other LISPS) do not evaluate the
>
> On Wed, Dec 31, 2008 at 2:10 PM, Werner LEMBERG <address@hidden> wrote:
> > I see the following remark in a recent git commit:
> >
> > Scrap localization wrapper around music functions docstrings.
> >
> > The l10n wrapper _i seems to prevent GUILE from recognizing the
> > docstrings as such.
> >
> > Looks like a bug or a bad `feature'.  Have you already contacted the
> > GUILE people for a workaround?
>
>
> If anything, this is not a GUILE problem, but a lilypond one.
> define-music-function as _i are Scheme macros.  It could be that the
> expansion does not occur correctly, but I know too little of macros to
> say something useful about this.
>
> Nicolas?

Huh, the only definition of _i that I find in the sources is
  (defmacro-public _i (x) x)
What is the point of that? Shouldn't it expand into the result of a call
to gettext?

Anyway, it seems that even with the current definition of _i, it cannot
be used for docstrings (I don't understand why).

guile> (macroexpand '(define-music-function (parser location) ()
                       (_i "blahblah")
                       (make-music 'Music)))
  (ly:make-music-function (list)
     (lambda (parser location)
       (_i "blahblah")
       (make-music (quote Music))))

Currently, no literal string is found after the arguments of lambda, so
no docstring is detected.

However, it is possible to call gettext during the expansion of
define-music-function, for instance:

guile> (defmacro-public define-music-function (args signature . body)
  (if (and (pair? body) (string? (car body)))
      (let ((docstring (gettext (car body)))
            (body (cdr body)))
        `(ly:make-music-function (list ,@signature)
                                 (lambda (,@args)
                                   ,docstring
                                   ,@body)))
      `(ly:make-music-function (list ,@signature)
                               (lambda (,@args)
                                 ,@body))))
guile> (macroexpand '(define-music-function (parser location) ()
                       "new tremolo format"
                       (make-music 'Music)))
  (ly:make-music-function (list)
    (lambda (parser location)
      "nouveau format de tremolo"
      (make-music (quote Music))))

Nicolas