Re: rhythm fragments in different pitches

[David Kastrup]

David Kastrup <address@hidden> writes:

> Kai Lautenschläger <address@hidden> writes:
>
>>> Am 22.09.2012 um 12:42 schrieb:
>>>
>>>> At some point of time, we probably should have a convenience function
>>>> for the pattern
>>>> 
>>>> (reverse! (fold-some-music [predicate]
>>>>                           (lambda (l m) (cons ([extractor] m) l))
>>>>                           '()
>>>>                           [music]))
>>>> 
>>>> The example code I posted uses this twice already.
>>
>>
>> Thanks for explaining. As for your idea [above] I would like that
>> feature very much, though I do not understand the code because I am
>> illiterate to programming languages.
>
> It turns out that the ([extractor] m) pattern can be equally well done
> separately using map!, so actually every function needed here is already
> available, making this somewhat simpler:

And actually, one does not need to nest the #{ #} constructs here, so
the following will do fine:

\language "deutsch"

rhythm = { s8.[ s16] }
melody = \relative c { a d g f e b}

applyRhythm =
#(define-music-function (parser location rhythm melody)
   (ly:music? ly:music?)
   #{ $@(append-map
         cons
         (map!
          (lambda (m) (ly:music-property m 'pitch))
          (extract-music melody
                         (lambda (m) (ly:music-property m 'pitch #f))))
         (apply circular-list
                (map!
                 (lambda (m) (cons (ly:music-property m 'duration)
                                   (ly:music-property m 'articulations)))
                 (extract-typed-music rhythm 'skip-event))))
   #})

\score {
\new Voice {
\relative c { g2 d8 h e4 f  } 
\applyRhythm \rhythm \melody
\relative c { g2 d8 h e4 f  } 
}
\layout {  }
}


-- 
David Kastrup