X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=scm%2Fmusic-functions.scm;h=8c2dc27f9c2b29ad9fcbbd4ff543cdce3fed4195;hb=07cba348de41ccb71a4707726b2f6c5510f33d49;hp=5011a0a0ee90a16188dd5ed0ebef052e81a8ab54;hpb=25073ea9fc0772d7282aa311dd57dceb9d921046;p=lilypond.git

diff --git a/scm/music-functions.scm b/scm/music-functions.scm
index 5011a0a0ee..8c2dc27f9c 100644
--- a/scm/music-functions.scm
+++ b/scm/music-functions.scm
@@ -1,11 +1,11 @@
-;;;; music-functions.scm -- implement Scheme output routines for PostScript
+;;;; music-functions.scm --
 ;;;;
 ;;;;  source file of the GNU LilyPond music typesetter
 ;;;; 
-;;;; (c)  1998--2004 Jan Nieuwenhuizen <janneke@gnu.org>
-;;;; Han-Wen Nienhuys <hanwen@cs.uu.nl>
+;;;; (c) 1998--2005 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;;                 Han-Wen Nienhuys <hanwen@cs.uu.nl>
 
-(use-modules (ice-9 optargs)) 
+;; (use-modules (ice-9 optargs)) 
 
 ;;; ly:music-property with setter
 ;;; (ly:music-property my-music 'elements)
@@ -21,7 +21,10 @@
 			      ly:grob-set-property!))
 
 (define-public (music-map function music)
-  "Apply @var{function} to @var{music} and all of the music it contains. "
+  "Apply @var{function} to @var{music} and all of the music it contains.
+
+First it recurses over the children, then the function is applied to MUSIC.
+"
   (let ((es (ly:music-property music 'elements))
 	(e (ly:music-property music 'element)))
     (set! (ly:music-property music 'elements) 
@@ -48,7 +51,7 @@
       (set! (ly:music-property music 'elements) filtered-es)
       (set! (ly:music-property music 'articulations) filtered-as)
       ;; if filtering emptied the expression, we remove it completely.
-      (if (or (pred? music)
+      (if (or (not (pred? music))
 	      (and (eq? filtered-es '()) (not (ly:music? e))
 		   (or (not (eq? es '()))
 		       (ly:music? e))))
@@ -60,22 +63,13 @@
       music
       (make-music 'Music)))	  ;must return music.
 
-(define-public (remove-tag tag)
-  (lambda (mus)
-    (music-filter
-     (lambda (m)
-       (let* ((tags (ly:music-property m 'tags))
-	      (res (memq tag tags)))
-	 res))
-     mus)))
-
 (define-public (display-music music)
   "Display music, not done with music-map for clarity of presentation."
   (display music)
   (display ": { ")  
   (let ((es (ly:music-property music 'elements))
 	(e (ly:music-property music 'element)))
-    (display (ly:get-mutable-properties music))
+    (display (ly:music-mutable-properties music))
     (if (pair? es)
 	(begin (display "\nElements: {\n")
 	       (map display-music es)
@@ -87,7 +81,6 @@
   (display " }\n")
   music)
 
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (define (shift-one-duration-log music shift dot)
@@ -109,7 +102,6 @@
 (define-public (shift-duration-log music shift dot)
   (music-map (lambda (x) (shift-one-duration-log x shift dot))
 	     music))
-  
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; clusters.
@@ -130,22 +122,37 @@
 
 (define-public (unfold-repeats music)
   "
-This function replaces all repeats  with unfold repeats. It was 
-written by Rune Zedeler. "
+This function replaces all repeats  with unfold repeats. "
+  
   (let ((es (ly:music-property music 'elements))
 	(e  (ly:music-property music 'element))
-	(n  (ly:music-name music)))
-    (if (equal? n "Repeated_music")
+	)
+    (if (memq 'repeated-music (ly:music-property music 'types))
 	(begin
 	  (if (equal? (ly:music-property music 'iterator-ctor)
 		      Chord_tremolo_iterator::constructor)
-	      (shift-duration-log music (ly:intlog2 (ly:music-property music 'repeat-count)) 0))
-	  (set! (ly:music-property music 'length)
+	      (let* ((seq-arg? (memq 'sequential-music
+				     (ly:music-property e 'types)))
+		     (count  (ly:music-property music 'repeat-count))
+		     (dot-shift (if (= 0 (remainder count 3))
+				    -1 0)))
+
+		(if (= 0 -1)
+		    (set! count (* 2 (quotient count 3))))
+		
+		(shift-duration-log music (+ (if seq-arg? 1 0)
+					     (ly:intlog2 count)) dot-shift)
+		
+		(if seq-arg?
+		    (ly:music-compress e (ly:make-moment (length (ly:music-property e 'elements)) 1)))))
+	  
+	  (set! (ly:music-property music 'length-callback)
 		Repeated_music::unfolded_music_length)
-	  (set! (ly:music-property music 'start-moment-function)
+	  (set! (ly:music-property music 'start-callback)
 		Repeated_music::first_start)
 	  (set! (ly:music-property music 'iterator-ctor)
 		Unfolded_repeat_iterator::constructor)))
+    
     (if (pair? es)
 	(set! (ly:music-property music 'elements)
 	      (map unfold-repeats es)))
@@ -154,7 +161,6 @@ written by Rune Zedeler. "
 	      (unfold-repeats e)))
     music))
 
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; property setting music objs.
 
@@ -182,27 +188,28 @@ i.e.  this is not an override"
 	      'grob-property gprop))
 
 (define direction-polyphonic-grobs
-  '(Tie Rest Slur Script TextScript Stem Dots DotColumn))
+  '(Stem Tie Rest Slur Script TextScript Dots DotColumn Fingering))
 
-(define-public (make-voice-props-set n)
+(define-safe-public (make-voice-props-set n)
   (make-sequential-music
    (append
     (map (lambda (x) (make-grob-property-set x 'direction
 					     (if (odd? n) -1 1)))
 	 direction-polyphonic-grobs)
-    (list (make-grob-property-set 'NoteColumn 'horizontal-shift (quotient n 2))
-	  (make-grob-property-set 'MultiMeasureRest 'staff-position
-				  (if (odd? n) -4 4))))))
+    (list
+     (make-grob-property-set 'NoteColumn 'horizontal-shift (quotient n 2))
+     (make-grob-property-set 'MultiMeasureRest 'staff-position (if (odd? n) -4 4)))))) 
 
-(define-public (make-voice-props-revert)
+(define-safe-public (make-voice-props-revert)
   (make-sequential-music
    (append
     (map (lambda (x) (make-grob-property-revert x 'direction))
 	 direction-polyphonic-grobs)
-    (list (make-grob-property-revert 'NoteColumn 'horizontal-shift)))))
+    (list (make-grob-property-revert 'NoteColumn 'horizontal-shift))
+    (list (make-grob-property-revert 'MultiMeasureRest 'staff-position)))))
 
 
-(define*-public (context-spec-music m context #:optional id)
+(define-safe-public (context-spec-music m context #:optional id)
   "Add \\context CONTEXT = ID to M. "
   (let ((cm (make-music 'ContextSpeccedMusic
 			'element m
@@ -211,6 +218,16 @@ i.e.  this is not an override"
 	(set! (ly:music-property cm 'context-id) id))
     cm))
 
+(define-public (descend-to-context m context)
+  "Like context-spec-music, but only descending. "
+  (let ((cm (context-spec-music m context)))
+    (ly:music-set-property! cm 'descend-only #t)
+    cm))
+
+(define-public (make-non-relative-music mus)
+  (make-music 'UnrelativableMusic
+	      'element mus))
+
 (define-public (make-apply-context func)
   (make-music 'ApplyContext
 	      'procedure func))
@@ -223,7 +240,7 @@ i.e.  this is not an override"
   (make-music 'SimultaneousMusic
 	      'elements elts))
 
-(define-public (make-event-chord elts)
+(define-safe-public (make-event-chord elts)
   (make-music 'EventChord
 	      'elements elts))
 
@@ -231,6 +248,10 @@ i.e.  this is not an override"
   (make-music 'SkipMusic
 	      'duration dur))
 
+(define-public (make-grace-music music)
+  (make-music 'GraceMusic
+	      'element music))
+
 ;;;;;;;;;;;;;;;;
 
 ;; mmrest
@@ -249,7 +270,7 @@ i.e.  this is not an override"
   "Check if we have R1*4-\\markup { .. }, and if applicable convert to
 a property set for MultiMeasureRestNumber."
   (define (script-to-mmrest-text script-music)
-    "Extract 'direction and 'text   from SCRIPT-MUSIC, and transform into property sets."
+    "Extract 'direction and 'text from SCRIPT-MUSIC, and transform into property sets."
     (let ((dir (ly:music-property script-music 'direction))
 	  (p   (make-music 'MultiMeasureTextEvent
 			   'text (ly:music-property script-music 'text))))
@@ -275,25 +296,25 @@ a property set for MultiMeasureRestNumber."
 (define-public (make-ottava-set octavation)
   (let ((m (make-music 'ApplyContext)))
     (define (ottava-modify context)
-      "Either reset centralCPosition to the stored original, or remember
-old centralCPosition, add OCTAVATION to centralCPosition, and set
+      "Either reset middleCPosition to the stored original, or remember
+old middleCPosition, add OCTAVATION to middleCPosition, and set
 OTTAVATION to `8va', or whatever appropriate."	    
-      (if (number? (ly:context-property	 context 'centralCPosition))
+      (if (number? (ly:context-property	 context 'middleCPosition))
 	  (if (= octavation 0)
-	      (let ((where (ly:context-property-where-defined context 'centralCPosition))
+	      (let ((where (ly:context-property-where-defined context 'middleCPosition))
 		    (oc0 (ly:context-property context 'originalCentralCPosition)))
-		(ly:context-set-property! context 'centralCPosition oc0)
-		(ly:unset-context-property where 'originalCentralCPosition)
-		(ly:unset-context-property where 'ottavation))
-	      (let* ((where (ly:context-property-where-defined context 'centralCPosition))
-		     (c0 (ly:context-property context 'centralCPosition))
+		(ly:context-set-property! context 'middleCPosition oc0)
+		(ly:context-unset-property where 'originalCentralCPosition)
+		(ly:context-unset-property where 'ottavation))
+	      (let* ((where (ly:context-property-where-defined context 'middleCPosition))
+		     (c0 (ly:context-property context 'middleCPosition))
 		     (new-c0 (+ c0 (* -7 octavation)))
 		     (string (cdr (assoc octavation '((2 . "15ma")
 						      (1 . "8va")
 						      (0 . #f)
 						      (-1 . "8va bassa")
 						      (-2 . "15ma bassa"))))))
-		(ly:context-set-property! context 'centralCPosition new-c0)
+		(ly:context-set-property! context 'middleCPosition new-c0)
 		(ly:context-set-property! context 'originalCentralCPosition c0)
 		(ly:context-set-property! context 'ottavation string)))))
     (set! (ly:music-property m 'procedure) ottava-modify)
@@ -303,10 +324,8 @@ OTTAVATION to `8va', or whatever appropriate."
   (ly:export (make-ottava-set ottavation)))
 
 (define-public (make-time-signature-set num den . rest)
-  " Set properties for time signature NUM/DEN.
-Rest can contain a list of beat groupings 
-
-"
+  "Set properties for time signature NUM/DEN.  Rest can contain a list
+of beat groupings "
   (let* ((set1 (make-property-set 'timeSignatureFraction (cons num den)))
 	 (beat (ly:make-moment 1 den))
 	 (len  (ly:make-moment num den))
@@ -316,11 +335,11 @@ Rest can contain a list of beat groupings
 						    (car rest)
 						    '())))
 	 (basic	 (list set1 set2 set3 set4)))
-    (context-spec-music
+    (descend-to-context
      (context-spec-music (make-sequential-music basic) 'Timing) 'Score)))
 
 (define-public (make-mark-set label)
-  "make the music for the \\mark command."  
+  "Make the music for the \\mark command."  
   (let* ((set (if (integer? label)
 		  (context-spec-music (make-property-set 'rehearsalMark label)
 				      'Score)
@@ -336,11 +355,12 @@ Rest can contain a list of beat groupings
 (define-public (set-time-signature num den . rest)
   (ly:export (apply make-time-signature-set `(,num ,den . ,rest))))
 
-(define-public (make-penalty-music pen)
+(define-safe-public (make-penalty-music pen page-pen)
   (make-music 'BreakEvent
-	      'penalty pen))
+	      'penalty pen
+	      'page-penalty page-pen))
 
-(define-public (make-articulation name)
+(define-safe-public (make-articulation name)
   (make-music 'ArticulationEvent
 	      'articulation-type name))
 
@@ -349,7 +369,7 @@ Rest can contain a list of beat groupings
 	      'duration duration
 	      'text string))
 
-(define-public (make-span-event type spandir)
+(define-safe-public (make-span-event type spandir)
   (make-music type
 	      'span-direction spandir))
 
@@ -365,24 +385,23 @@ Rest can contain a list of beat groupings
   (let ((ts (ly:music-property m 'types)))
     (memq 'separator ts)))
 
-
 ;;; splitting chords into voices.
 (define (voicify-list lst number)
-   "Make a list of Musics.
+  "Make a list of Musics.
 
    voicify-list :: [ [Music ] ] -> number -> [Music]
    LST is a list music-lists.
 
    NUMBER is 0-base, i.e. Voice=1 (upstems) has number 0.
 "
-   (if (null? lst)
-       '()
-       (cons (context-spec-music
-	      (make-sequential-music
-	       (list (make-voice-props-set number)
-		     (make-simultaneous-music (car lst))))
-	      'Voice  (number->string (1+ number)))
-	     (voicify-list (cdr lst) (1+ number)))))
+  (if (null? lst)
+      '()
+      (cons (context-spec-music
+	     (make-sequential-music
+	      (list (make-voice-props-set number)
+		    (make-simultaneous-music (car lst))))
+	     'Voice  (number->string (1+ number)))
+	    (voicify-list (cdr lst) (1+ number)))))
 
 (define (voicify-chord ch)
   "Split the parts of a chord into different Voices using separator"
@@ -398,11 +417,12 @@ Rest can contain a list of beat groupings
 	     (error "not music!")))
   (let ((es (ly:music-property m 'elements))
 	(e (ly:music-property m 'element)))
+
     (if (pair? es)
 	(set! (ly:music-property m 'elements) (map voicify-music es)))
     (if (ly:music? e)
 	(set! (ly:music-property m 'element)  (voicify-music e)))
-    (if (and (equal? (ly:music-name m) "Simultaneous_music")
+    (if (and (equal? (ly:music-property m 'name) 'SimultaneousMusic)
 	     (reduce (lambda (x y ) (or x y)) #f (map music-separator? es)))
 	(set! m (context-spec-music (voicify-chord m) 'Staff)))
     m))
@@ -411,7 +431,7 @@ Rest can contain a list of beat groupings
   (ly:export (make-music 'Music)))
 ;;;
 
-; Make a function that checks score element for being of a specific type. 
+					; Make a function that checks score element for being of a specific type. 
 (define-public (make-type-checker symbol)
   (lambda (elt)
     ;;(display	symbol)
@@ -424,14 +444,14 @@ Rest can contain a list of beat groupings
 
 
 (define-public ((set-output-property grob-name symbol val)  grob grob-c context)
-   "Usage:
+  "Usage:
 
 \\applyoutput #(set-output-property 'Clef 'extra-offset '(0 . 1))
 
 "
-   (let ((meta (ly:grob-property grob 'meta)))
-     (if (equal?  (cdr (assoc 'name meta)) grob-name)
-	 (set! (ly:grob-property grob symbol) val))))
+  (let ((meta (ly:grob-property grob 'meta)))
+    (if (equal?  (cdr (assoc 'name meta)) grob-name)
+	(set! (ly:grob-property grob symbol) val))))
 
 
 ;;
@@ -455,7 +475,7 @@ Rest can contain a list of beat groupings
 (define (has-request-chord elts)
   (reduce (lambda (x y) (or x y)) #f
 	  (map (lambda (x)
-		 (equal? (ly:music-name x) "Request_chord"))
+		 (equal? (ly:music-property x 'name) 'RequestChord))
 	       elts)))
 
 (define (ly:music-message music msg)
@@ -463,19 +483,19 @@ Rest can contain a list of beat groupings
     (if (ly:input-location? ip)
 	(ly:input-message ip msg)
 	(ly:warn msg))))
-  
+
 (define (check-start-chords music)
   "Check music expression for a Simultaneous_music containing notes\n(ie. Request_chords),
 without context specification. Called  from parser."
   (let ((es (ly:music-property music 'elements))
 	(e (ly:music-property music 'element))
-	(name (ly:music-name music)))
+	(name (ly:music-property music 'name)))
     (cond ((equal? name "Context_specced_music") #t)
 	  ((equal? name "Simultaneous_music")
 	   (if (has-request-chord es)
-	       (ly:music-message music "Starting score with a chord.\nPlease insert an explicit \\context before chord")
+	       (ly:music-message music "Starting score with a chord.\nInsert an explicit \\context before chord")
 	       (map check-start-chords es)))
-	  ((equal? name "Sequential_music")
+	  ((equal? name "SequentialMusic")
 	   (if (pair? es)
 	       (check-start-chords (car es))))
 	  (else (if (ly:music? e) (check-start-chords e)))))
@@ -490,9 +510,8 @@ without context specification. Called  from parser."
 
 (define (vector-extend v x)
   "Make a new vector consisting of V, with X added to the end."
-  (let*
-      ((n (vector-length v))
-       (nv (make-vector (+ n 1) '())))
+  (let* ((n (vector-length v))
+	 (nv (make-vector (+ n 1) '())))
     (vector-move-left! v 0 n nv 0)
     (vector-set! nv n x)
     nv))
@@ -516,30 +535,83 @@ without context specification. Called  from parser."
   (define (set-prop context)
     (let* ((where (ly:context-property-where-defined context 'graceSettings))
 	   (current (ly:context-property where 'graceSettings))
-	   (new-settings (vector-extend current (list context-name grob sym val))))
+	   (new-settings (append current
+				 (list (list context-name grob sym val)))))
       (ly:context-set-property! where 'graceSettings new-settings)))
   (ly:export (context-spec-music (make-apply-context set-prop) 'Voice)))
 
 
-(define-public (set-start-grace-properties context)
-  (define (execute-1 x)
-    (let ((tr (ly:translator-find context (car x))))
-      (if (ly:context? tr)
-	  (ly:context-pushpop-property tr (cadr x) (caddr x) (cadddr x)))))
-  
-  (let ((props (ly:context-property context 'graceSettings)))
-    (if (vector? props)
-	(vector-map execute-1 props))))
-
-(define-public (set-stop-grace-properties context)
-  (define (execute-1 x)
-    (let ((tr (ly:translator-find context (car x))))
-      (if (ly:context? tr)
-	  (ly:context-pushpop-property tr (cadr x) (caddr x)))))
+
+(defmacro-public def-grace-function (start stop)
+  `(def-music-function (parser location music) (ly:music?)
+     (make-music 'GraceMusic
+		 'origin location
+		 'element (make-music 'SequentialMusic
+				      'elements (list (ly:music-deep-copy ,start)
+						      music
+						      (ly:music-deep-copy ,stop))))))
+
+(defmacro-public def-music-function (args signature . body)
+  "Helper macro for `ly:make-music-function'.
+Syntax:
+  (def-music-function (parser location arg1 arg2 ...) (arg1-type? arg2-type? ...)
+    ...function body...)
+"
+  `(ly:make-music-function (list ,@signature)
+			   (lambda (,@args)
+			     ,@body)))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(define-public (cue-substitute quote-music)
+  "Must happen after quote-substitute."
   
-  (let ((props (ly:context-property context 'graceSettings)))
-    (if (vector? props)
-	(vector-reverse-map execute-1 props))))
+  (if (vector? (ly:music-property quote-music 'quoted-events))
+      (let* ((dir (ly:music-property quote-music 'quoted-voice-direction))
+	     (main-voice (if (eq? 1 dir) 1 0))
+	     (cue-voice (if (eq? 1 dir) 0 1))
+	     (main-music (ly:music-property quote-music 'element))
+	     (return-value quote-music))
+	
+	(if (or (eq? 1 dir) (eq? -1 dir))
+	    
+	    ;; if we have stem dirs, change both quoted and main music
+	    ;; to have opposite stems.
+	    (begin
+	      (set! return-value
+
+		    ;; cannot context-spec Quote-music, since context
+		    ;; for the quotes is determined in the iterator.
+		    (make-sequential-music
+		     (list
+		      (context-spec-music (make-voice-props-set cue-voice) 'Voice "cue")
+		      quote-music
+		      (context-spec-music (make-voice-props-revert)  'Voice "cue"))))
+	      (set! main-music
+		    (make-sequential-music
+		     (list
+		      (make-voice-props-set main-voice)
+		      main-music
+		      (make-voice-props-revert))))
+	      (set! (ly:music-property quote-music 'element) main-music)))
+
+	return-value)
+      quote-music))
+
+(define-public ((quote-substitute quote-tab) music)
+  (let* ((quoted-name (ly:music-property music 'quoted-music-name))
+	 (quoted-vector (if (string? quoted-name)
+			    (hash-ref quote-tab quoted-name #f)
+			    #f)))
+    
+    (if (string? quoted-name)
+	(if  (vector? quoted-vector)
+	     (set! (ly:music-property music 'quoted-events) quoted-vector)
+	     (ly:warn "Cannot find quoted music `~S'" quoted-name)))
+
+    music))
+
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; switch it on here, so parsing and init isn't checked (too slow!)
@@ -547,16 +619,41 @@ without context specification. Called  from parser."
 ;; automatic music transformations.
 
 (define (switch-on-debugging m)
-  (set-debug-cell-accesses! 15000)
+  (if (defined? 'set-debug-cell-accesses!)
+      (set-debug-cell-accesses! 15000))
   m)
 
+(define (music-check-error music)
+  (define found #f)
+  (define (signal m)
+    (if (and (ly:music? m)
+	     (eq? (ly:music-property m 'error-found) #t))
+	(set! found #t)))
+  
+  (for-each signal (ly:music-property music 'elements))
+  (signal (ly:music-property music 'element))
+
+  (if found
+      (set! (ly:music-property music 'error-found) #t))
+  music)
+
+(define (precompute-music-length music)
+  (set! (ly:music-property music 'length)
+	(ly:music-length music))
+  music)
+
 (define-public toplevel-music-functions
   (list
    ;; check-start-chords ; ; no longer needed with chord syntax. 
-   voicify-music
-   (lambda (x) (music-map glue-mm-rest-texts x))
+   (lambda (music parser) (voicify-music music))
+   (lambda (x parser) (music-map glue-mm-rest-texts x))
+   (lambda (x parser) (music-map music-check-error x))
+   (lambda (x parser) (music-map precompute-music-length x))
+   (lambda (music parser)
+
+     (music-map (quote-substitute (ly:parser-lookup parser 'musicQuotes))  music))
    ;; switch-on-debugging
-   ))
+   (lambda (x parser) (music-map cue-substitute x))))
 
 ;;;;;;;;;;;;;;;;;
 ;; lyrics
@@ -576,7 +673,7 @@ without context specification. Called  from parser."
 ;;
 
 (define-public ((add-balloon-text object-name text off) grob orig-context cur-context)
-   "Usage: see input/regression/balloon.ly "
+  "Usage: see input/regression/balloon.ly "
   (let* ((meta (ly:grob-property grob 'meta))
 	 (nm (if (pair? meta) (cdr (assoc 'name meta)) "nonexistant"))
 	 (cb (ly:grob-property grob 'print-function)))
@@ -605,12 +702,12 @@ without context specification. Called  from parser."
 
 (define-public (set-accidental-style style . rest)
   "Set accidental style to STYLE. Optionally takes a context argument,
-eg. 'Staff or 'Voice. The context defaults to Voice, except for piano styles, which
-use PianoStaff as a context. "
+e.g. 'Staff or 'Voice. The context defaults to Voice, except for piano styles, which
+use GrandStaff as a context. "
   (let ((context (if (pair? rest)
 		     (car rest) 'Staff))
 	(pcontext (if (pair? rest)
-		      (car rest) 'PianoStaff)))
+		      (car rest) 'GrandStaff)))
     (ly:export
      (cond
       ;; accidentals as they were common in the 18th century.
@@ -645,7 +742,7 @@ use PianoStaff as a context. "
       ;; as cautionaries
       ((equal? style 'modern-voice-cautionary)
        (set-accidentals-properties #f
-				   '(Voice (same-octave . 0) )
+				   '(Voice (same-octave . 0))
 				   '(Voice (any-octave . 0) (same-octave . 1)
 					   Staff (same-octave . 0) (any-octave . 0) (same-octave . 1))
 				   context))
@@ -653,15 +750,16 @@ use PianoStaff as a context. "
       ;; Accidentals are cancelled across the staves in the same grand staff as well
       ((equal? style 'piano)
        (set-accidentals-properties #f
-				   '( Staff (same-octave . 0) (any-octave . 0) (same-octave . 1)
-					    PianoStaff (any-octave . 0) (same-octave . 1))
+				   '(Staff (same-octave . 0)
+					   (any-octave . 0) (same-octave . 1)
+					   GrandStaff (any-octave . 0) (same-octave . 1))
 				   '()
 				   pcontext))
       ((equal? style 'piano-cautionary)
        (set-accidentals-properties #f
 				   '(Staff (same-octave . 0))
 				   '(Staff (any-octave . 0) (same-octave . 1)
-					   PianoStaff (any-octave . 0) (same-octave . 1))
+					   GrandStaff (any-octave . 0) (same-octave . 1))
 				   pcontext))
       ;; do not set localKeySignature when a note alterated differently from
       ;; localKeySignature is found.
@@ -681,7 +779,25 @@ use PianoStaff as a context. "
 				   '()
 				   context))
       (else
-       (ly:warn (string-append "Unknown accidental style: " (symbol->string style)))
+       (ly:warn "Unknown accidental style: ~S" (symbol->string style))
        (make-sequential-music '()))))))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(define-public (skip-of-length mus)
+  "Create a skip of exactly the same length as MUS."
+  (let* ((skip
+	  (make-music
+	   'SkipEvent
+	   'duration (ly:make-duration 0 0))))
 
+    (make-event-chord (list (ly:music-compress skip (ly:music-length mus))))))
+
+(define-public (mmrest-of-length mus)
+  "Create a mmrest of exactly the same length as MUS."
+  
+  (let* ((skip
+	  (make-multi-measure-rest
+	   (ly:make-duration 0 0) '())))
+    (ly:music-compress skip (ly:music-length mus))
+    skip))