Re: function that inserts a toplevel expression

[Urs Liska]

Hi David,

thank you for the reply

Am 10.05.2012 12:05, schrieb David Kastrup:
> Urs Liska<address@hidden>  writes:
>
> > So now the question:
> > How can I write a function that produces a toplevel expression?
> No such thing.
:-(
> > I want to be able to write:
> >
> > \debugCurvesOn
> >
> > or
> >
> > #(debug-curves-on)
> >
> > (or something similar) which should then expand to
> >
> > \layout {
> >    \context {
> >      \Score
> >      \override Slur #'stencil = #(display-control-points)
> >      \override PhrasingSlur #'stencil = #(display-control-points)
> > \override Tie #'stencil = #(display-control-points) }
> > }
> >
> > (you see where this is going? ;-) )
> debugCurvesOn = \layout {
>     \context {
>       \Score
>       \override Slur #'stencil = #(display-control-points)
>       \override PhrasingSlur #'stencil = #(display-control-points)
>   \override Tie #'stencil = #(display-control-points) }
> }
>
> That created a layout definition (more accurately: an output definition
> suitable for use in layouts).  Which can be used in \layout:
>
> \layout { \debugCurvesOn  [Other stuff ...] }
OK, instead of

\debugCurvesOn

I now have to insert

\layout { \debutCurvesOn }

in my main file.
It is not perfectly what I had hoped for, but it's fine nevertheless 
(definitely better than the current solution).
So we may consider this as solved.
> If you want to turn this into a function, you use define-scheme-function
> and construct the return value using #{ \layout { ... } #}.
Not necessary anymore. But I think I see now better how this works.
> > Furthermore I will later want to write functions for the \score block,
> > and I will want to pass some parameters in there - which doesn't work
> > with include files.
> Not clear to me what you want.
I wanted to be able to write

\liedScore "Stimme" "Klavier"
or
\liedScore "Voice" "Piano"
and get back the respective \score block with the parameters substituted.
But from your answers to the other part of the question I now know that 
this isn't possible.

Probably I'll look for a solution through defining a variable and then 
including the file with the \score definition.
For the project at hand it's not necessary because I can have the score 
block be hardcoded. But I want to distill a more generic 
library/framework for use after this project.

Thanks again
Urs