Re: banter-style from chord-names-jazz.ly broken, 'case'-problem

[Thomas Morley]

2015-04-08 11:45 GMT+02:00 Thomas Morley <address@hidden>:
> Hi.
>
> I started to rewrite chord-namings and stumbled over a problem in
> chord-generic-names.ly
>
> /Documentation/included/chord-names-jazz.ly with uncommented
> Banter-style is broken.
> At least since 2.12.3
>
> The problem is in 'step->markup-plusminus'
>
> Here you see the old code commented and a possible patch inserted:
>
>   (define (step->markup-plusminus pitch)
>     (make-line-markup
>      (list
>       (make-simple-markup (number->string (step-nr pitch)))
>       (make-simple-markup
>        ;(case (step-alteration pitch)
>        ;  ((DOUBLE-FLAT) "--")
>        ;  ((FLAT) "-")
>        ;  ((NATURAL) "")
>        ;  ((SHARP) "+")
>        ;  ((DOUBLE-SHARP) "++"))
>        (case (step-alteration pitch)
>          ((-1) "--")
>          ((-1/2) "-")
>          ((0) "")
>          ((1/2) "+")
>          ((1) "++"))
>        ))))
>
> case uses eqv? to compare. (guile-manual)
> (step-alteration pitch) returns: -1 or -1/2 or 0 or 1/2 or 1
> (display (eqv? -1/2 FLAT), etc returns #t

boiled down:

(display DOUBLE-FLAT)
-> -1

(display (eqv? -1 DOUBLE-FLAT))
-> #t

(display
 (case -1
   ((DOUBLE-FLAT) "--")
   ((FLAT) "-")
   ((NATURAL) "")
   ((SHARP) "+")
   ((DOUBLE-SHARP) "++")))
-> #<unspecified>

??

> Thus I've no clue why the old code fails.
> Any hint?
>
> Cheers,
>   Harm