[Denemo-devel] The scheme problem: example

[Richard Shann]

In case you are wondering how I stumbled on the string-join problem,
here is my filter for entering figured bass by playing the notes
specified. It requires the latest git for the function d-BassFigure
which returns the bass figure for a given interval in the current key
signature (actually the initial keysig at the moment).
The long series of (display xxx) lines are debugging the problem which
is revealed as string-join being unbound.
Richard

;;;;;;;;;;;;
;;; Figured Bass filter

(d-PutMidi 0);;; Our own Reset, this makes the filter toggle off/on
(define Figures "_")

(define trans 0);;0 semi up

(define AddFigure (lambda (note);;fixme pass both or neither...
                    (begin
                      (display "adding a figure")
                      (display Figures)
                      (set! Figures (cons  (d-BassFigure bassnote note) 
Figures)))))


(define GetFigures (lambda ()
                     (begin
(display Figures)
(display list> Figures)
(display "true?")


(display (list? Figures))
(display Figures)
(display "true?")

(display  (list? (reverse Figures)))
(display "going to try accessing string-join")
(display string-join)
(display "hooray")
(display (string-join (reverse Figures)))

(string-append "figures=" (string-join (reverse Figures))))))


(define midi 0)
(define velocity 0)
(define command 0)
(define bassnote 0)
(define note 0)

(define loop  (lambda ()
                (begin
                  (display "bassnote")
                  (display bassnote)
                  (set! midi (d-GetMidi))
                  (set! velocity (bit-extract midi 16 24))
                  (set! note (bit-extract midi 8 16))
                  (set! command (bit-extract midi 0 8))
                 (display "midi message ")
                 (display `(,command ,note ,velocity))
                   (if (= command #x90)
                       (begin
                         (if (and (> velocity 0)(= bassnote 0))
                             (begin 
                               (display "bass note on")
                               (display note)
                               (set! bassnote note)
                               (set! Figures '())
                               (d-PutMidi midi)
                                (display "inserted bass note"))
                             ;;; not bass note on 
                             (if (and (= velocity 0)(= note bassnote))
                                 (begin 
                                   (display "bass note off")
                                   (set! bassnote 0)
                                   (d-EditFiguredBass (GetFigures))
                                   (d-PutMidi midi))
                                 ;;; not bass note off
                                 (if  (> velocity 0)
                                      (begin
                                      (AddFigure note)
                                      (display Figures)))))))
                   (if (and (= command #xB0) (= note #x40) (= velocity #x7F))   
   
                       (begin
                         (display "Pedal down")
                         (set! Figures (cons Figures " | "))))
                   (if (not (= command 0))
                       (loop))
                   )))
(loop)
(display "finished bass figure filter")
;;; to force it to finish run a script that does (d-PutMidi 0)