Re:

[Nicolas Sceaux]

Bertalan Fodor <address@hidden> writes:

> Sorry for replying myself again, but I figured out that I don't need
> to guess the length of the parameter list with the lambda, I just can
> use:
>
>      \once \override Voice.NoteHead #'glyph-name-procedure = #(lambda
>      p "1" )
>
> This p (which is essentially a list) will get all the parameters that
> are given.
> So this structure can always be used to substitute original procedures.
>
> Bert

A cleaner way is to look at the doc and see what is expected for the
glyph-name-procedure property:

<http://lilypond.org/doc/v2.7/Documentation/user/out-www/lilypond-internals/NoteHead.html>
glyph-name-procedure (procedure):
  find-notehead-symbol
  Return the name of a character within font, to use for printing a
  symbol. 

Hm, let's see what `find-notehead-symbol' looks like:

robert:~/src/lilypond/lilypond/scm nicolas$ grep find-notehead-symbol *
...
output-lib.scm:(define-public (find-notehead-symbol duration style)

So, 'glyph-name-procedure expects a two arguments procedure. By looking
a the source code of the function in scm/output-lib.scm, we learn what
these arguments looks like: duration is an integer number, and style a
symbol among xcircle, harmonic, baroque, mensural, petrucci,
neomensural, default, or something beginning with vaticana, hufnagel or
medicaea.

nicolas