From df9fc0bd0d50943cdc48d4226009bd30c3e99fe4 Mon Sep 17 00:00:00 2001 From: David Kastrup Date: Sat, 7 Nov 2015 00:22:58 +0100 Subject: [PATCH] Issue 4654: offset-fret modifies its definition --- scm/predefined-fretboards.scm | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/scm/predefined-fretboards.scm b/scm/predefined-fretboards.scm index cad0c3b620..5f4d7005cd 100644 --- a/scm/predefined-fretboards.scm +++ b/scm/predefined-fretboards.scm @@ -38,20 +38,17 @@ and return a marking list, which can be used with a fretboard grob." (if (string? diagram-definition) (parse-terse-string diagram-definition) diagram-definition))) - (map (lambda(item) - (let ((code (car item))) - (cond - ((eq? code 'barre) - (list-set! item 3 - (+ fret-offset (list-ref item 3))) - item) - ((eq? code 'capo) - (list-set! item 1 - (+ fret-offset (list-ref item 1))) - item) - ((eq? code 'place-fret) - (list-set! item 2 - (+ fret-offset (list-ref item 2))) - item) - (else item)))) + (map (lambda (item) + (let* ((code (car item)) + (nth (assq-ref '((barre . 3) (capo . 1) (place-fret . 2)) + code))) + (if nth + ;; offset nth element of item by offset-fret + ;; without modifying the original list but + ;; sharing its tail + (let ((tail (list-tail item nth))) + (append! (list-head item nth) + (cons (+ (car tail) fret-offset) + (cdr tail)))) + item))) verbose-definition))) -- 2.39.5