+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; output signatures.
+
+(define-public (write-system-signatures basename paper-systems count)
+ (if (pair? paper-systems)
+ (begin
+ (let*
+ ((outname (simple-format #f "~a-~a.signature" basename count)) )
+
+ (ly:message "Writing ~a" outname)
+ (write-system-signature outname (car paper-systems))
+ (write-system-signatures basename (cdr paper-systems) (1+ count))))))
+
+(use-modules (scm paper-system))
+(define-public (write-system-signature filename paper-system)
+ (define (float? x)
+ (and (number? x) (inexact? x)))
+
+ (define system-grob
+ (paper-system-system-grob paper-system))
+
+ (define output (open-output-file filename))
+
+ ;; todo: optionally use a command line flag? Or just junk this?
+ (define compare-expressions #f)
+ (define (strip-floats expr)
+ "Replace floats by #f"
+ (cond
+ ((float? expr) #f)
+ ((ly:font-metric? expr) (ly:font-name expr))
+ ((pair? expr) (cons (strip-floats (car expr))
+ (strip-floats (cdr expr))))
+ (else expr)))
+
+ (define (fold-false-pairs expr)
+ "Try to remove lists of #f as much as possible."
+ (if (pair? expr)
+ (let*
+ ((first (car expr))
+ (rest (fold-false-pairs (cdr expr))))
+
+ (if first
+ (cons (fold-false-pairs first) rest)
+ rest))
+ expr))
+
+ (define (raw-string expr)
+ "escape quotes and slashes for python consumption"
+ (regexp-substitute/global #f "[@\n]" (simple-format #f "~a" expr) 'pre " " 'post))
+
+ (define (raw-pair expr)
+ (simple-format #f "~a ~a"
+ (car expr) (cdr expr)))
+
+ (define (found-grob expr)
+ (let*
+ ((grob (car expr))
+ (rest (cdr expr))
+ (collected '())
+ (cause (event-cause grob))
+ (input (if (ly:stream-event? cause) (ly:event-property cause 'origin) #f))
+ (location (if (ly:input-location? input) (ly:input-file-line-char-column input) '()))
+
+ ;; todo: use stencil extent if available.
+ (x-ext (ly:grob-extent grob system-grob X))
+ (y-ext (ly:grob-extent grob system-grob Y))
+ (expression-skeleton
+ (if compare-expressions
+ (interpret-for-signature
+ #f (lambda (e)
+ (set! collected (cons e collected)))
+ rest)
+ "")))
+
+ (simple-format output
+ "~a@~a@~a@~a@~a\n"
+ (cdr (assq 'name (ly:grob-property grob 'meta) ))
+ (raw-string location)
+ (raw-pair (if (interval-empty? x-ext) '(1 . -1) x-ext))
+ (raw-pair (if (interval-empty? y-ext) '(1 . -1) y-ext))
+ (raw-string collected))
+ ))
+
+ (define (interpret-for-signature escape collect expr)
+ (define (interpret expr)
+ (let*
+ ((head (if (pair? expr)
+ (car expr)
+ #f)))
+
+ (cond
+ ((eq? head 'grob-cause) (escape (cdr expr)))
+ ((eq? head 'color) (interpret (caddr expr)))
+ ((eq? head 'rotate-stencil) (interpret (caddr expr)))
+ ((eq? head 'translate-stencil) (interpret (caddr expr)))
+ ((eq? head 'combine-stencil)
+ (for-each (lambda (e) (interpret e)) (cdr expr)))
+ (else
+ (collect (fold-false-pairs (strip-floats expr))))
+
+ )))
+
+ (interpret expr))
+
+ (if (ly:grob? system-grob)
+ (begin
+ (display (simple-format #f "# Output signature\n# Generated by LilyPond ~a\n" (lilypond-version))
+ output)
+ (interpret-for-signature found-grob (lambda (x) #f)
+ (ly:stencil-expr
+ (paper-system-stencil paper-system)))))
+
+ ;; should be superfluous, but leaking "too many open files"?
+ (close-port output))
+