ly/chord-repetition-init.ly

   1 %%% -*- Mode: Scheme -*-
   2 \version "2.13.9"
   3 %{
   4
   5 The following functions define the chord repetition behavior, and may
   6 be invoked by the user to customize it.
   7
   8 ly:parser-set-repetition-symbol
   9   set the chord repetition shortcut.
  10   `q' is the default value set in this file.
  11
  12 ly:parser-set-repetition-function
  13
  14   set the function that is invoked when a chord repetition symbol
  15   is encountered by the parser: a four argument function
  16   (previous-chord, location, duration, list of articulations) which is
  17   supposed to return a new chord.
  18   `default-repeat-chord' is the default function set in this file.
  19 %}
  20
  21 #(define-public (default-repeat-chord previous-chord location duration articulations)
  22    "Copy the previous chord, filter out events which are not notes, set
  23 the chord duration, add articulations."
  24    ;; If previous-chord has an length property, then it means that it
  25    ;; has been processed by a music iterator.  In other words, the chord
  26    ;; has been memorized in an other music block, which is certainly not
  27    ;; what the user has intended.  In that case, raise a warning.
  28    (if (not (and (ly:music? previous-chord)
  29                  (null? (ly:music-property previous-chord 'length))))
  30        (ly:input-message location
  31                          (_ "No memorized chord in music block before chord repetition")))
  32    ;; Instead of copying the previous chord, then removing the
  33    ;; undesired elements (like articulations), a new empty chord is
  34    ;; built.  Then, the pitch found in the previous chord are added to
  35    ;; the new chord, without any "decoration" (e.g. cautionary
  36    ;; accidentals, fingerings, text scripts, articulations).
  37    (make-music
  38     'EventChord
  39     'origin location
  40     'elements (append! (filter identity
  41                                (map (lambda (event)
  42                                       (and (eqv? (ly:music-property event 'name) 'NoteEvent)
  43                                            (make-music
  44                                             'NoteEvent
  45                                             'pitch (ly:music-property event 'pitch)
  46                                             'duration duration)))
  47                                     (ly:music-property previous-chord 'elements)))
  48                        articulations)))
  49
  50 #(ly:parser-set-repetition-symbol parser 'q)
  51 #(ly:parser-set-repetition-function parser default-repeat-chord)