Re: Creating markup macros (functions actually)

[Paul Scott]

Nicolas Sceaux wrote:

> Paul Scott <address@hidden> writes:
>
>  
>
> > Does this make any sense?
> >
> > #(def-markup-command (testOne layout props) ()
> >  (interpret-markup layout props
> >   (markup #:number
> >    (lambda (x) (ly:music-property x 'numerator)))))
> >    
>
> No.
>
> (lambda ...) evaluates to a function,
That I understand.

> where you want a markup. 
That I don't yet.  Another look at new-markup-scm tells me a markup is a 
list?

> Remember that the \number markup command takes a markup as an
> argument, not a procedure.
>
> When you want to parametrize (uh) a LilyPond expression, the first
> thing to do is to write it, in plain LilyPond syntax, and then display
> it in Scheme.
How do I display it in Scheme?  I see you answer that below but it 
breaks right now.

> Then you will have a pattern to use in your function
> body. (What you want is a music function, not a markup command).
>
> for instance, supposing that `mus:display' (see
> http://lists.gnu.org/archive/html/lilypond-devel/2004-11/msg00029.html)
>  
That's a little complicated at the moment but I'm getting there.

> is defined in music-display.scm:
>
> -----test.ly-----
> #(load "music-display.scm")
> #(mus:display #{ R1^\markup \number 1 #})
> -----test.ly-----
>
>  
I get:
address@hidden:~/music/test$ lilypond-snapshot displayscheme.ly
GNU LilyPond 2.4.2
Processing `displayscheme.ly'
Parsing...
Backtrace:
In unknown file:
  ?: 0* [primitive-load "music-display.scm"]

<unnamed port>: In procedure open-file in expression (primitive-load name):
<unnamed port>: No such file or directory: "music-display.scm"

> ==>
> (make-music 'SequentialMusic
>  'elements (list
>             (make-music 'MultiMeasureRestMusicGroup
>               'elements (list
>                          (make-music 'BarCheck)
>                          (make-music 'EventChord
>                            'elements (list
>                                       (make-music 'MultiMeasureRestEvent
>                                         'duration (ly:make-duration 0 0 1 1))))
>                          (make-music 'BarCheck)
>                          (make-music 'TextScriptEvent
>                            'direction 1
>                            'text (list
>                                       number-markup
>                                       (markup #:simple "1")))))))
>  
That will help a lot.

> > > See scm/new-markups.scm.
> > >      
This is beginning to make sense but I still have a way to go.

> > I'll keep reading this but I don't understand it yet.  Can you
> > recommend any online reading to understand scheme better?
> >    
>
> I don't know much about scheme community sites. www.schemers.org
> should have links to tutorials and books.
>  
Duh!  I was there several times and missed the one link I needed which 
took me to:

http://www.htdp.org/2003-09-26/

Thanks so much for all your help and patience.  I have been programming 
for many years in many languages but have only looked at scheme and lisp 
recently.

Paul