Re: [frogs] Guitar capo code in scheme

[Marc Hohl <marc@xxxxxxxxxx>]

Am 20.07.2011 23:18, schrieb Wols Lists:
> On 20/07/11 01:05, Carl Sorensen wrote:
> > With the exceptions I've noted above, it looks great!  I think this will do
> > exactly what you want done, and it will satisfy my concerns and Neil's
> > concerns.  Great job!
> Okay, I've tried to follow what you've said, and make the appropriate
> changes. Patches attached. But it won't run :-( and I'm pretty certain
> I've messed up the "let(" syntax.
>
> I've looked at the scheme tutor "structure and interpretation..." and
> while I sort of understand what's going on, I haven't quite got it yet.
>
> Anyways, here's the code:
>
> (define-public (capo-handler pitches bass inversion context)
>    (let (chord-function (ly:context-property context 'chordNameFunction #f))
At a quick glace, I think here is the error:

let must be followed by two parentheses:

(let ((foo ( ... ))
        (bar ( ... ))

        ...function calls follow here... ))

>      (capo-pitch (ly:context-property context 'capoPitch #f))
And here ends the variable block, add another ")" in the line above.

I didn't test it, though.

HTH,

Marc
>      (if  (not (capo-pitch))                 ;; if there's no capo pitch
> or no chord
>        (chord-function pitches bass inversion context)     ;; call the
> chordNameFunction as of old
>        (let ((new-pitches                                       ;; else
> transpose the pitches and do the chord twice
>              (map (lambda (p)
>                (ly:pitch-transpose p capo-pitch))
>            pitches))
>            (new-bass
>              (and (ly:pitch? bass)
>                (ly:pitch-transpose bass capo-pitch)))
>            (new-inversion
>              (and (ly:pitch? inversion)
>                (ly:pitch-transpose inversion
>            capo-pitch)))
>
>            (capo-markup (make-parenthesize-markup (chord-function
> new-pitches new-bass new-inversion context)))
>            (markup (chord-function pitches bass  inversion context))
>
>            (capo-vertical (ly:context-property context 'capoVertical #f))
>            (if (capo-vertical)
>              (make-column-markup (list markup capo-markup))
>              (make-line-markup (list markup (make-hspace-markup 1)
> capo-markup))))))))
>
> And the error:
>
> anthony@ashdown ~/gitstuff/music/Hymnal/Choruses $ lilypond
> HeGaveMeBeautyForAshes.ly
> GNU LilyPond 2.15.6
> Processing `HeGaveMeBeautyForAshes.ly'
> Parsing...
> Interpreting music... ERROR: In procedure memoization:
> ERROR: In file "/usr/local/share/lilypond/2.15.6/scm/chord-name.scm",
> line 173: Bad binding chord-function in expression (let (chord-function
> (ly:context-property context (quote chordNameFunction) #f)) (capo-pitch
> (ly:context-property context (quote capoPitch) #f)) (if (not
> (capo-pitch)) (chord-function pitches bass inversion context) (let
> ((new-pitches (map (lambda # #) pitches)) (new-bass (and (ly:pitch?
> bass) (ly:pitch-transpose bass capo-pitch))) (new-inversion (and
> (ly:pitch? inversion) (ly:pitch-transpose inversion capo-pitch)))
> (capo-markup (make-parenthesize-markup (chord-function new-pitches
> new-bass new-inversion context))) (markup (chord-function pitches bass
> inversion context)) (capo-vertical (ly:context-property context (quote
> capoVertical) #f)) (if (capo-vertical) (make-column-markup (list markup
> capo-markup)) (make-line-markup (list markup # capo-markup))))))).
> anthony@ashdown ~/gitstuff/music/Hymnal/Choruses $
>
> Cheers,
> Wol


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