Add Scheme context-mods, reimplement \grobdescriptions, add \settingsFrom

[lilypond.git] / ly / music-functions-init.ly

diff --git a/ly/music-functions-init.ly b/ly/music-functions-init.ly
index 3b3a5b4c3aff88f6c8fb40eb50b3f60e8c76b7aa..8b5cddf013b85acc882b66c15c8be09878375430 100644 (file)
--- a/ly/music-functions-init.ly
+++ b/ly/music-functions-init.ly
@@ -402,6 +402,15 @@ grace =
 #(def-grace-function startGraceMusic stopGraceMusic
    (_i "Insert @var{music} as grace notes."))
 
+grobdescriptions =
+#(define-scheme-function (parser location descriptions) (list?)
+   (_i "Create a context modification from @var{descriptions}, a list
+in the format of @code{all-grob-descriptions}.")
+   (ly:make-context-mod
+    (map (lambda (p)
+          (list 'assign (car p) (list (cdr p))))
+        descriptions)))
+
 harmonicByFret = #(define-music-function (parser location fret music) (number? ly:music?)
   (_i "Convert @var{music} into harmonics; the resulting notes resemble
 harmonics played on a fretted instrument by touching the strings above @var{fret}.")
@@ -974,6 +983,44 @@ scaleDurations =
    (ly:music-compress music
                      (ly:make-moment (car fraction) (cdr fraction))))
 
+settingsFrom =
+#(define-scheme-function (parser location ctx music)
+   ((symbol?) ly:music?)
+   (_i "Take the layout instruction events from @var{music}, optionally
+restricted to those applying to context type @var{ctx}, and return
+a context modification duplicating their effect.")
+   (let ((mods (ly:make-context-mod)))
+     (define (musicop m)
+       (if (music-is-of-type? m 'layout-instruction-event)
+          (ly:add-context-mod
+           mods
+           (case (ly:music-property m 'name)
+             ((PropertySet)
+              (list 'assign
+                    (ly:music-property m 'symbol)
+                    (ly:music-property m 'value)))
+             ((PropertyUnset)
+              (list 'unset
+                    (ly:music-property m 'symbol)))
+             ((OverrideProperty)
+              (list 'push
+                    (ly:music-property m 'symbol)
+                    (ly:music-property m 'grob-property-path)
+                    (ly:music-property m 'grob-value)))
+             ((RevertProperty)
+              (list 'pop
+                    (ly:music-property m 'symbol)
+                    (ly:music-property m 'grob-property-path)))))
+          (case (ly:music-property m 'name)
+            ((SequentialMusic SimultaneousMusic)
+             (for-each musicop (ly:music-property m 'elements)))
+            ((ContextSpeccedMusic)
+             (if (or (not ctx)
+                     (eq? ctx (ly:music-property m 'context-type)))
+                 (musicop (ly:music-property m 'element)))))))
+     (musicop music)
+     mods))
+
 shiftDurations =
 #(define-music-function (parser location dur dots arg)
    (integer? integer? ly:music?)
@@ -1117,7 +1164,6 @@ void =
 Use this if you want to have a scheme expression evaluated
 because of its side-effects, but its value ignored."))
 
-
 withMusicProperty =
 #(define-music-function (parser location sym val music)
    (symbol? scheme? ly:music?)