Clear fret-diagram- and harp-pedal-input-strings from whitespace

issue 4575

Whitespace-characters are deleted before further processing.

Allows for
\markup \fret-diagram #"s:2;h:5;
6-3;5-5;4-5;3-4;2-3;1-x;"

Also adding errors for typos in fret-diagram with a meaningful message:
\markup \fret-diagram #"s:2;g:r;
6-3;5-5;4-5;3-4;2-3;1-x;"
will return:
fatal error: Unhandled entry in fret-diagram "g:r" in "g:r"

This error would not apply, if something for #\g would be defined
in fret-parse-definition-string somewhere in the future.

Then, the message would be:
fatal error: Unhandled entry in fret-diagram "r" in "g:r"

Something similiar is already in harp-pedals.scm

3 files changed, 36 insertions, 7 deletions

diff --git a/scm/fret-diagrams.scm b/scm/fret-diagrams.scm
index 041d180c04..85cfbb9b36 100644
--- a/scm/fret-diagrams.scm
+++ b/scm/fret-diagrams.scm
@@ -44,7 +44,15 @@ to end-point."
 
 (define (get-numeric-from-key keystring)
   "Get the numeric value from a key of the form k:val"
-  (string->number (substring keystring 2 (string-length keystring))))
+  (let* ((entry (substring keystring 2 (string-length keystring)))
+         (numeric-entry (string->number entry)))
+    ;; throw an error, if `entry' can't be transformed into a number
+    (if numeric-entry
+        numeric-entry
+        (ly:error
+          "Unhandled entry in fret-diagram \"~a\" in \"~a\""
+          entry
+          keystring))))
 
 (define (numerify mylist)
   "Convert string values to numeric or character"
@@ -245,7 +253,11 @@ with magnification @var{mag} of the string @var{text}."
              ((or (eq? my-code 'open)(eq? my-code 'mute))
               (set! xo-list (cons* my-item xo-list)))
              ((eq? my-code 'barre)
-              (set! barre-list (cons* (cdr my-item) barre-list)))
+              (if (every number? (cdr my-item))
+                  (set! barre-list (cons* (cdr my-item) barre-list))
+                  (ly:error
+                    "barre-indications should contain only numbers: ~a"
+                    (cdr my-item))))
              ((eq? my-code 'capo)
               (set! capo-fret (cadr my-item)))
              ((eq? my-code 'place-fret)
@@ -923,7 +935,9 @@ a fret-indication list with the appropriate values"
          (output-list '())
          (new-props '())
          (details (merge-details 'fret-diagram-details props '()))
-         (items (string-split definition-string #\;)))
+         ;; remove whitespace-characters from definition-string
+         (cleared-string (remove-whitespace definition-string))
+         (items (string-split cleared-string #\;)))
     (let parse-item ((myitems items))
       (if (not (null? (cdr myitems)))
           (let ((test-string (car myitems)))
@@ -959,7 +973,15 @@ a fret-indication list with the appropriate values"
                        (set! details
                              (acons 'dot-position dot-position details))))
               (else
-               (let ((this-list (string-split test-string #\-)))
+               (let* ((this-list (string-split test-string #\-))
+                      (fret-number (string->number (car this-list))))
+                 ;; If none of the above applies, `fret-number' needs to be a
+                 ;; number. Throw an error, if not.
+                 (if (not fret-number)
+                   (ly:error
+                     "Unhandled entry in fret-diagrams \"~a\" in \"~a\""
+                     (car this-list)
+                     test-string))
                  (if (string->number (cadr this-list))
                      (set! output-list
                            (cons-fret
@@ -968,11 +990,11 @@ a fret-indication list with the appropriate values"
                      (if (equal? (cadr this-list) "x" )
                          (set! output-list
                                (cons-fret
-                                (list 'mute (string->number (car this-list)))
+                                (list 'mute fret-number)
                                 output-list))
                          (set! output-list
                                (cons-fret
-                                (list 'open (string->number (car this-list)))
+                                (list 'open fret-number)
                                 output-list)))))))
             (parse-item (cdr myitems)))))
     ;; add the modified details
diff --git a/scm/harp-pedals.scm b/scm/harp-pedals.scm
index a6c93774d3..9365f0a034 100644
--- a/scm/harp-pedals.scm
+++ b/scm/harp-pedals.scm
@@ -132,6 +132,7 @@ spacing after the divider).
            stencils)))
 
 ;; Parse the harp pedal definition string into list of directions (-1/0/1), #\o and #\|
+;; Whitespace is removed from definition string before the procedure applies.
 (define (harp-pedals-parse-string definition-string)
   "Parse a harp pedals diagram string and return a list containing 1, 0, -1, #\\o or #\\|"
   (map (lambda (c)
@@ -141,7 +142,7 @@ spacing after the divider).
            ((#\-) 0)
            ((#\| #\o) c)
            (else c)))
-       (string->list definition-string)))
+       (string->list (remove-whitespace definition-string))))
 
 
 ;; Analyze the pedal-list: Return (pedalcount . (divider positions))
diff --git a/scm/lily-library.scm b/scm/lily-library.scm
index 2270726902..c5bf8cc59d 100644
--- a/scm/lily-library.scm
+++ b/scm/lily-library.scm
@@ -786,6 +786,12 @@ as rectangular coordinates @ode{(x-length . y-length)}."
 (define-public (string-startswith s prefix)
   (equal? prefix (substring s 0 (min (string-length s) (string-length prefix)))))
 
+(define-public (remove-whitespace strg)
+"Remove characters satisfying @code{char-whitespace?} from string @var{strg}"
+  (string-delete
+    strg
+    char-whitespace?))
+
 (define-public (string-encode-integer i)
   (cond
    ((= i  0) "o")