Re: Scheme problem?

[Simon Albrecht]

Am 12.02.2015 um 17:00 schrieb takumi ikeda:
> Hi Kevin,
> Thank you for your reply. But the part of "(if (= UP dir) -0.5 0.5)"
> seems to not working...
>
> BTW, How can I learn the syntax like "(ly:duration-log
> (ly:music-property music 'duration))"? I found the documentation
> lilypond.org/doc/v2.19/Documentation/internals/scheme-functions but it
> says only "Function: ly:duration-log dur". Is "dur" an data type?
> Where is the reference of "dur"?
“dur” serves as a placeholder for an argument. You should find it again 
in the explanatory text on the function, which is sometimes very short. 
In fact, the argument referenced here as “dur” is of type ly:duration? – 
that’s the data type. Durations may be created through the scheme 
function ly:make-duration.

HTH, Simon
> 2015-02-12 22:13 GMT+09:00 Kevin Barry <address@hidden>:
> > Hi Takumi,
> >
> > Is this what you want?
> >
> > \version "2.18.2"
> >
> > tremps = #"
> > 2 setlinewidth
> > 0.07 0.07 scale
> > -10 7 moveto
> > -5 3 5 3 10 7 curveto
> > -10 -7 lineto
> > -5 -3 5 -3 10 -7 curveto
> > stroke
> > "
> >
> > z-trem =
> > #(define-music-function (parser location music) (ly:music?)
> >     #{
> >       \override StemTremolo.stencil =
> >       #(lambda (grob)
> >          (let* (
> >                  (dur-log (ly:duration-log (ly:music-property music
> > 'duration)))
> >                  (dir (ly:grob-property grob 'direction))
> >                  )
> >            (grob-interpret-markup grob
> >              (markup
> >               (
> >                 #:translate (cons 0 (if (= 0 dur-log)
> >                                         0
> >                                         (if (= UP dir) -0.5 0.5)))
> >                 #:postscript tremps
> >                 )
> >               )
> >              )
> >            )
> >          )
> >       $music
> >     #}
> >     )
> >
> >
> > \new Staff {
> >    \z-trem
> >    c'1:32 c''8: f'16: g':  c''8: c'4: c''16:
> > }
> >
> > On Thu, Feb 12, 2015 at 12:44 PM, takumi ikeda <address@hidden> wrote:
> > > Hello all,
> > >
> > > I am trying the following code but I got "Wrong type: ()" error.
> > > I would like to avoid translating tremolos when the note is whole note.
> > > Writing Scheme is quite difficult for me. Any help would be appreciated.
> > >
> > > Takumi
> > >
> > > \version "2.18.2"
> > >
> > > tremps = #"
> > > 2 setlinewidth
> > > 0.07 0.07 scale
> > > -10 7 moveto
> > > -5 3 5 3 10 7 curveto
> > > -10 -7 lineto
> > > -5 -3 5 -3 10 -7 curveto
> > > stroke
> > > "
> > >
> > > z-trem =
> > > #(define-music-function (parser location music) (ly:music?)
> > >     #{
> > >       \override StemTremolo.stencil =
> > >       #(lambda (grob)
> > >          (let* (
> > >                  (dur-log (ly:grob-property grob 'duration-log))
> > >                  (dir (ly:grob-property grob 'direction))
> > >                  )
> > >            (grob-interpret-markup grob
> > >              (markup
> > >               (
> > >                 #:translate (cons 0 (if (= 0 dur-log) 0
> > >                                         (if (= UP dir) -0.5 0.5)))
> > >                 #:postscript tremps
> > >                 )
> > >               )
> > >              )
> > >            )
> > >          )
> > >       $music
> > >     #}
> > >     )
> > >
> > >
> > > \new Staff {
> > >    \z-trem
> > >    c'1:32 c''8: f'16: g':  c''8: c'4: c''16:
> > > }
> > >
> > > _______________________________________________
> > > lilypond-user mailing list
> > > address@hidden
> > > https://lists.gnu.org/mailman/listinfo/lilypond-user
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