Re: tiny function

[Thomas Morley]

2016-07-01 0:05 GMT+02:00 Br. Gabriel-Marie | SSPX <address@hidden>:
> Thanks, Mr. Meyn,
>
> That certainly does the trick.
>
> So you can't write macros for \with{} statements?
> Why couldn't I do it this way, if I just want to create the \with statement?

Obviously a call of a scheme-function is not allowed instead of a
\with-expression, opposed to a static value stored in vavariable:

\version "2.19.44"

%% fails:
tstI =
#(define-scheme-function ()()
#{ \with { instrumentName = "foo" shortInstrumentName = "foo" } #})
\new Staff \tstI { r1 }

%% works:
tstII =
\with { instrumentName = "foo" shortInstrumentName = "foo" }
\new Staff \tstII { r1 }


There are other possibilities, though:

\version "2.19.44"

%% (1)
#(define (foo nmbr)
#{
    \with {
      instrumentName = #(format #f "~a." nmbr)
      shortInstrumentName = #(format #f "~a." nmbr)
    }
#})

\new Staff $(foo 1) { r1 }


%%(2)
buzz =
#(define-scheme-function (nmbr)(number?)
#{
    \with {
      instrumentName = #(format #f "~a." nmbr)
      shortInstrumentName = #(format #f "~a." nmbr)
    }
#})
\new Staff \with { \buzz #2 } { r1 }


%%(3)
#(define (set-instrument-names-to-number-string nmbr mus)
        (if (eq? (ly:music-property mus 'name) 'ContextSpeccedMusic)
            (ly:music-set-property! mus 'property-operations
              (list
                (list
                  'assign
                  'instrumentName
                  (format #f "~a." nmbr))
                (list
                  'assign
                  'shortInstrumentName
                  (format #f "~a." nmbr))))
              mus)
            mus)

tst =
#(define-music-function (nmbr mus)(number? ly:music?)
(set-instrument-names-to-number-string nmbr mus))

\tst #3 \new Staff { r1 }


HTH,
  Harm