lilypond-data 2.16.2-3 / usr / share / lilypond / 2.16.2 / scm / music-functions.scm

;;;; This file is part of LilyPond, the GNU music typesetter.
;;;;
;;;; Copyright (C) 1998--2012 Jan Nieuwenhuizen <janneke@gnu.org>
;;;;                 Han-Wen Nienhuys <hanwen@xs4all.nl>
;;;;
;;;; LilyPond is free software: you can redistribute it and/or modify
;;;; it under the terms of the GNU General Public License as published by
;;;; the Free Software Foundation, either version 3 of the License, or
;;;; (at your option) any later version.
;;;;
;;;; LilyPond is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;;; GNU General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU General Public License
;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.

; for define-safe-public when byte-compiling using Guile V2
(use-modules (scm safe-utility-defs))

(use-modules (ice-9 optargs))

;;; ly:music-property with setter
;;; (ly:music-property my-music 'elements)
;;;   ==> the 'elements property
;;; (set! (ly:music-property my-music 'elements) value)
;;;   ==> set the 'elements property and return it
(define-public ly:music-property
  (make-procedure-with-setter ly:music-property
			      ly:music-set-property!))

(define-safe-public (music-is-of-type? mus type)
  "Does @code{mus} belong to the music class @code{type}?"
  (memq type (ly:music-property mus 'types)))

;; TODO move this
(define-public ly:grob-property
  (make-procedure-with-setter ly:grob-property
			      ly:grob-set-property!))

(define-public ly:grob-object
  (make-procedure-with-setter ly:grob-object
			      ly:grob-set-object!))

(define-public ly:grob-parent
  (make-procedure-with-setter ly:grob-parent
			      ly:grob-set-parent!))

(define-public ly:prob-property
  (make-procedure-with-setter ly:prob-property
			      ly:prob-set-property!))

(define-public ly:context-property
  (make-procedure-with-setter ly:context-property
			      ly:context-set-property!))

(define-public (music-map function music)
  "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
@var{music}."
  (let ((es (ly:music-property music 'elements))
	(e (ly:music-property music 'element)))
    (if (pair? es)
	(set! (ly:music-property music 'elements)
	      (map (lambda (y) (music-map function y)) es)))
    (if (ly:music? e)
	(set! (ly:music-property music 'element)
	      (music-map function  e)))
    (function music)))

(define-public (music-filter pred? music)
  "Filter out music expressions that do not satisfy @var{pred?}."

  (define (inner-music-filter pred? music)
    "Recursive function."
    (let* ((es (ly:music-property music 'elements))
	   (e (ly:music-property music 'element))
	   (as (ly:music-property music 'articulations))
	   (filtered-as (filter ly:music? (map (lambda (y) (inner-music-filter pred? y)) as)))
	   (filtered-e (if (ly:music? e)
			   (inner-music-filter pred? e)
			   e))
	   (filtered-es (filter ly:music? (map (lambda (y) (inner-music-filter pred? y)) es))))
      (if (not (null? e))
	  (set! (ly:music-property music 'element) filtered-e))
      (if (not (null? es))
	  (set! (ly:music-property music 'elements) filtered-es))
      (if (not (null? as))
	  (set! (ly:music-property music 'articulations) filtered-as))
      ;; if filtering emptied the expression, we remove it completely.
      (if (or (not (pred? music))
	      (and (eq? filtered-es '()) (not (ly:music? e))
		   (or (not (eq? es '()))
		       (ly:music? e))))
	  (set! music '()))
      music))

  (set! music (inner-music-filter pred? music))
  (if (ly:music? music)
      music
      (make-music 'Music)))	  ;must return music.

(define*-public (display-music music #:optional (port (current-output-port)))
  "Display music, not done with @code{music-map} for clarity of
presentation."
  (display music port)
  (display ": { " port)
  (let ((es (ly:music-property music 'elements))
	(e (ly:music-property music 'element)))
    (display (ly:music-mutable-properties music) port)
    (if (pair? es)
	(begin (display "\nElements: {\n" port)
	       (for-each (lambda (m) (display-music m port)) es)
	       (display "}\n" port)))
    (if (ly:music? e)
	(begin
	  (display "\nChild:" port)
	  (display-music e port))))
  (display " }\n" port)
  music)

;;;
;;; A scheme music pretty printer
;;;
(define (markup-expression->make-markup markup-expression)
  "Transform `markup-expression' into an equivalent, hopefuly readable, scheme expression.
For instance,
  \\markup \\bold \\italic hello
==>
  (markup #:line (#:bold (#:italic (#:simple \"hello\"))))"
  (define (proc->command-keyword proc)
    "Return a keyword, eg. `#:bold', from the `proc' function, eg. #<procedure bold-markup (layout props arg)>"
    (let ((cmd-markup (symbol->string (procedure-name proc))))
      (symbol->keyword (string->symbol (substring cmd-markup 0 (- (string-length cmd-markup)
								  (string-length "-markup")))))))
  (define (transform-arg arg)
    (cond ((and (pair? arg) (markup? (car arg))) ;; a markup list
	   (apply append (map inner-markup->make-markup arg)))
	  ((and (not (string? arg)) (markup? arg)) ;; a markup
	   (inner-markup->make-markup arg))
	  (else					 ;; scheme arg
	   (music->make-music arg))))
  (define (inner-markup->make-markup mrkup)
    (if (string? mrkup)
	`(#:simple ,mrkup)
	(let ((cmd (proc->command-keyword (car mrkup)))
	      (args (map transform-arg (cdr mrkup))))
	  `(,cmd ,@args))))
  ;; body:
  (if (string? markup-expression)
      markup-expression
      `(markup ,@(inner-markup->make-markup markup-expression))))

(define-public (music->make-music obj)
  "Generate an expression that, once evaluated, may return an object
equivalent to @var{obj}, that is, for a music expression, a
@code{(make-music ...)} form."
  (cond (;; markup expression
	 (markup? obj)
	 (markup-expression->make-markup obj))
	(;; music expression
	 (ly:music? obj)
	 `(make-music
	   ',(ly:music-property obj 'name)
	   ,@(apply append (map (lambda (prop)
                                  `(',(car prop)
				    ,(music->make-music (cdr prop))))
                                (remove (lambda (prop)
                                          (eqv? (car prop) 'origin))
                                        (ly:music-mutable-properties obj))))))
	(;; moment
	 (ly:moment? obj)
	 `(ly:make-moment ,(ly:moment-main-numerator obj)
			  ,(ly:moment-main-denominator obj)
			  ,(ly:moment-grace-numerator obj)
			  ,(ly:moment-grace-denominator obj)))
	(;; note duration
	 (ly:duration? obj)
	 `(ly:make-duration ,(ly:duration-log obj)
			    ,(ly:duration-dot-count obj)
			    ,(ly:duration-scale obj)))
	(;; note pitch
	 (ly:pitch? obj)
	 `(ly:make-pitch ,(ly:pitch-octave obj)
			 ,(ly:pitch-notename obj)
			 ,(ly:pitch-alteration obj)))
	(;; scheme procedure
	 (procedure? obj)
	 (or (procedure-name obj) obj))
	(;; a symbol (avoid having an unquoted symbol)
	 (symbol? obj)
	 `',obj)
	(;; an empty list (avoid having an unquoted empty list)
	 (null? obj)
	 `'())
	(;; a proper list
	 (list? obj)
	 `(list ,@(map music->make-music obj)))
	(;; a pair
	 (pair? obj)
	 `(cons ,(music->make-music (car obj))
		,(music->make-music (cdr obj))))
	(else
	 obj)))

(use-modules (ice-9 pretty-print))
(define*-public (display-scheme-music obj #:optional (port (current-output-port)))
  "Displays `obj', typically a music expression, in a friendly fashion,
which often can be read back in order to generate an equivalent expression."
  (pretty-print (music->make-music obj) port)
  (newline port))

;;;
;;; Scheme music expression --> Lily-syntax-using string translator
;;;
(use-modules (srfi srfi-39)
             (scm display-lily))

(define*-public (display-lily-music expr parser #:optional (port (current-output-port))
				    #:key force-duration)
  "Display the music expression using LilyPond syntax"
  (memoize-clef-names supported-clefs)
  (parameterize ((*indent* 0)
		 (*previous-duration* (ly:make-duration 2))
		 (*force-duration* force-duration))
    (display (music->lily-string expr parser) port)
    (newline port)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define-public (shift-one-duration-log music shift dot)
  "Add @var{shift} to @code{duration-log} of @code{'duration} in
@var{music} and optionally @var{dot} to any note encountered.
The number of dots in the shifted music may not be less than zero."
  (let ((d (ly:music-property music 'duration)))
    (if (ly:duration? d)
	(let* ((cp (ly:duration-scale d))
	       (nd (ly:make-duration
                    (+ shift (ly:duration-log d))
                    (max 0 (+ dot (ly:duration-dot-count d)))
		    cp)))
	  (set! (ly:music-property music 'duration) nd)))
    music))

(define-public (shift-duration-log music shift dot)
  (music-map (lambda (x) (shift-one-duration-log x shift dot))
	     music))

(define-public (make-repeat name times main alts)
  "Create a repeat music expression, with all properties initialized
properly."
  (define (first-note-duration music)
    "Finds the duration of the first NoteEvent by searching depth-first
through MUSIC."
    ;; NoteEvent or a non-expanded chord-repetition
    ;; We just take anything that actually sports an announced duration.
    (if (ly:duration? (ly:music-property music 'duration))
	(ly:music-property music 'duration)
	(let loop ((elts (if (ly:music? (ly:music-property music 'element))
			     (list (ly:music-property music 'element))
			     (ly:music-property music 'elements))))
	  (and (pair? elts)
	       (let ((dur (first-note-duration (car elts))))
		 (if (ly:duration? dur)
		     dur
		     (loop (cdr elts))))))))

  (let ((talts (if (< times (length alts))
		   (begin
		     (ly:warning (_ "More alternatives than repeats.  Junking excess alternatives"))
		     (take alts times))
		   alts))
	(r (make-repeated-music name)))
    (set! (ly:music-property r 'element) main)
    (set! (ly:music-property r 'repeat-count) (max times 1))
    (set! (ly:music-property r 'elements) talts)
    (if (and (equal? name "tremolo")
	     (pair? (extract-named-music main '(EventChord NoteEvent))))
	;; This works for single-note and multi-note tremolos!
	(let* ((children (if (music-is-of-type? main 'sequential-music)
			     ;; \repeat tremolo n { ... }
			     (length (extract-named-music main '(EventChord
								 NoteEvent)))
			     ;; \repeat tremolo n c4
			     1))
	       ;; # of dots is equal to the 1 in bitwise representation (minus 1)!
	       (dots (1- (logcount (* times children))))
	       ;; The remaining missing multiplicator to scale the notes by
	       ;; times * children
	       (mult (/ (* times children (ash 1 dots)) (1- (ash 2 dots))))
	       (shift (- (ly:intlog2 (floor mult))))
	       (note-duration (first-note-duration r))
	       (duration-log (if (ly:duration? note-duration)
				 (ly:duration-log note-duration)
				 1))
	       (tremolo-type (ash 1 duration-log)))
	  (set! (ly:music-property r 'tremolo-type) tremolo-type)
	  (if (not (and (integer? mult) (= (logcount mult) 1)))
	      (ly:music-warning
	       main
	       (ly:format (_ "invalid tremolo repeat count: ~a") times)))
	  ;; Adjust the time of the notes
	  (ly:music-compress r (ly:make-moment 1 children))
	  ;; Adjust the displayed note durations
	  (shift-duration-log r shift dots))
	r)))

(define (calc-repeat-slash-count music)
  "Given the child-list @var{music} in @code{PercentRepeatMusic},
calculate the number of slashes based on the durations.  Returns @code{0}
if durations in @var{music} vary, allowing slash beats and double-percent
beats to be distinguished."
  (let* ((durs (map duration-of-note
		    (extract-named-music music '(EventChord NoteEvent
						 RestEvent SkipEvent))))
	 (first-dur (car durs)))

    (if (every (lambda (d) (equal? d first-dur)) durs)
	(max (- (ly:duration-log first-dur) 2) 1)
	0)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; clusters.

(define-public (note-to-cluster music)
  "Replace @code{NoteEvents} by @code{ClusterNoteEvents}."
  (if (eq? (ly:music-property music 'name) 'NoteEvent)
      (make-music 'ClusterNoteEvent
		  'pitch (ly:music-property music 'pitch)
		  'duration (ly:music-property music 'duration))
      music))

(define-public (notes-to-clusters music)
  (music-map note-to-cluster music))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; repeats.

(define-public (unfold-repeats music)
  "Replace all repeats with unfolded repeats."

  (let ((es (ly:music-property music 'elements))
	(e (ly:music-property music 'element)))

    (if (music-is-of-type? music 'repeated-music)
	(let* ((props (ly:music-mutable-properties music))
	       (old-name (ly:music-property music 'name))
	       (flattened (flatten-alist props)))
	  (set! music (apply make-music (cons 'UnfoldedRepeatedMusic
					      flattened)))

	  (if (and (equal? old-name 'TremoloRepeatedMusic)
		   (pair? (extract-named-music e '(EventChord NoteEvent))))
	      ;; This works for single-note and multi-note tremolos!
	      (let* ((children (if (music-is-of-type? e 'sequential-music)
				   ;; \repeat tremolo n { ... }
				   (length (extract-named-music e '(EventChord
								       NoteEvent)))
				   ;; \repeat tremolo n c4
				   1))
		     (times (ly:music-property music 'repeat-count))

		     ;; # of dots is equal to the 1 in bitwise representation (minus 1)!
		     (dots (1- (logcount (* times children))))
		     ;; The remaining missing multiplicator to scale the notes by
		     ;; times * children
		     (mult (/ (* times children (ash 1 dots)) (1- (ash 2 dots))))
		     (shift (- (ly:intlog2 (floor mult)))))

		;; Adjust the time of the notes
		(ly:music-compress music (ly:make-moment children 1))
		;; Adjust the displayed note durations
		(shift-duration-log music (- shift) (- dots))))))

    (if (pair? es)
	(set! (ly:music-property music 'elements)
	      (map unfold-repeats es)))
    (if (ly:music? e)
	(set! (ly:music-property music 'element)
	      (unfold-repeats e)))
    music))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; property setting music objs.

(define-public (make-grob-property-set grob gprop val)
  "Make a @code{Music} expression that sets @var{gprop} to @var{val} in
@var{grob}.  Does a pop first, i.e., this is not an override."
  (make-music 'OverrideProperty
	      'symbol grob
	      'grob-property gprop
	      'grob-value val
	      'pop-first #t))

(define-public (make-grob-property-override grob gprop val)
  "Make a @code{Music} expression that overrides @var{gprop} to @var{val}
in @var{grob}."
  (make-music 'OverrideProperty
	      'symbol grob
	      'grob-property gprop
	      'grob-value val))

(define-public (make-grob-property-revert grob gprop)
  "Revert the grob property @var{gprop} for @var{grob}."
  (make-music 'RevertProperty
	      'symbol grob
	      'grob-property gprop))

(define direction-polyphonic-grobs
  '(AccidentalSuggestion
    DotColumn
    Dots
    Fingering
    LaissezVibrerTie
    LigatureBracket
    PhrasingSlur
    RepeatTie
    Rest
    Script
    Slur
    Stem
    TextScript
    Tie
    TupletBracket
    TrillSpanner))

(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-property-set 'graceSettings
			;; TODO: take this from voicedGraceSettings or similar.
			'((Voice Stem font-size -3)
			  (Voice Flag font-size -3)
			  (Voice NoteHead font-size -3)
			  (Voice TabNoteHead font-size -4)
			  (Voice Dots font-size -3)
			  (Voice Stem length-fraction 0.8)
			  (Voice Stem no-stem-extend #t)
			  (Voice Beam beam-thickness 0.384)
			  (Voice Beam length-fraction 0.8)
			  (Voice Accidental font-size -4)
			  (Voice AccidentalCautionary font-size -4)
			  (Voice Script font-size -3)
			  (Voice Fingering font-size -8)
			  (Voice StringNumber font-size -8)))

     (make-grob-property-set 'NoteColumn 'horizontal-shift (quotient n 2))
     (make-grob-property-set 'MultiMeasureRest 'staff-position (if (odd? n) -4 4))))))

(define-safe-public (make-voice-props-override n)
  (make-sequential-music
   (append
    (map (lambda (x) (make-grob-property-override x 'direction
						  (if (odd? n) -1 1)))
	 direction-polyphonic-grobs)
    (list
     (make-property-set 'graceSettings
			;; TODO: take this from voicedGraceSettings or similar.
			'((Voice Stem font-size -3)
			  (Voice Flag font-size -3)
			  (Voice NoteHead font-size -3)
			  (Voice TabNoteHead font-size -4)
			  (Voice Dots font-size -3)
			  (Voice Stem length-fraction 0.8)
			  (Voice Stem no-stem-extend #t)
			  (Voice Beam beam-thickness 0.384)
			  (Voice Beam length-fraction 0.8)
			  (Voice Accidental font-size -4)
			  (Voice AccidentalCautionary font-size -4)
			  (Voice Script font-size -3)
			  (Voice Fingering font-size -8)
			  (Voice StringNumber font-size -8)))

     (make-grob-property-override 'NoteColumn 'horizontal-shift (quotient n 2))
     (make-grob-property-override 'MultiMeasureRest 'staff-position (if (odd? n) -4 4))))))

(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-property-unset 'graceSettings)
	  (make-grob-property-revert 'NoteColumn 'horizontal-shift)
	  (make-grob-property-revert 'MultiMeasureRest 'staff-position)))))


(define-safe-public (context-spec-music m context #:optional id)
  "Add \\context CONTEXT = ID to M."
  (let ((cm (make-music 'ContextSpeccedMusic
			'element m
			'context-type context)))
    (if (string? id)
	(set! (ly:music-property cm 'context-id) id))
    cm))

(define-public (descend-to-context m context)
  "Like @code{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))

(define-public (make-sequential-music elts)
  (make-music 'SequentialMusic
	      'elements elts))

(define-public (make-simultaneous-music elts)
  (make-music 'SimultaneousMusic
	      'elements elts))

(define-safe-public (make-event-chord elts)
  (make-music 'EventChord
	      'elements elts))

(define-public (make-skip-music dur)
  (make-music 'SkipMusic
	      'duration dur))

(define-public (make-grace-music music)
  (make-music 'GraceMusic
	      'element music))

;;;;;;;;;;;;;;;;

;; mmrest
(define-public (make-multi-measure-rest duration location)
  (make-music 'MultiMeasureRestMusic
	      'origin location
	      'duration duration))

(define-public (make-property-set sym val)
  (make-music 'PropertySet
	      'symbol sym
	      'value val))

(define-public (make-property-unset sym)
  (make-music 'PropertyUnset
	      'symbol sym))

(define-safe-public (make-articulation name)
  (make-music 'ArticulationEvent
	      'articulation-type name))

(define-public (make-lyric-event string duration)
  (make-music 'LyricEvent
	      'duration duration
	      'text string))

(define-safe-public (make-span-event type span-dir)
  (make-music type
	      'span-direction span-dir))

(define-public (override-head-style heads style)
  "Override style for @var{heads} to @var{style}."
  (make-sequential-music
    (if (pair? heads)
        (map (lambda (h)
              (make-grob-property-override h 'style style))
         heads)
        (list (make-grob-property-override heads 'style style)))))

(define-public (revert-head-style heads)
  "Revert style for @var{heads}."
  (make-sequential-music
    (if (pair? heads)
        (map (lambda (h)
              (make-grob-property-revert h 'style))
         heads)
        (list (make-grob-property-revert heads 'style)))))

(define-public (style-note-heads heads style music)
 "Set @var{style} for all @var{heads} in @var{music}.  Works both
inside of and outside of chord construct."
  ;; are we inside a <...>?
  (if (eq? (ly:music-property music 'name) 'NoteEvent)
      ;; yes -> use a tweak
      (begin
        (set! (ly:music-property music 'tweaks)
              (acons 'style style (ly:music-property music 'tweaks)))
        music)
      ;; not in <...>, so use overrides
      (make-sequential-music
        (list
          (override-head-style heads style)
          music
          (revert-head-style heads)))))

 (define-public (set-mus-properties! m alist)
  "Set all of @var{alist} as properties of @var{m}."
  (if (pair? alist)
      (begin
	(set! (ly:music-property m (caar alist)) (cdar alist))
	(set-mus-properties! m (cdr alist)))))

(define-public (music-separator? m)
  "Is @var{m} a separator?"
  (let ((ts (ly:music-property m 'types)))
    (memq 'separator ts)))

;;; expanding repeat chords
(define-public (copy-repeat-chord original-chord repeat-chord duration
				  event-types)
  "Copies all events in @var{event-types} (be sure to include
@code{rhythmic-events}) from @var{original-chord} over to
@var{repeat-chord} with their articulations filtered as well.  Any
duration is replaced with the specified @var{duration}."
  ;; First remove everything from event-types that can already be
  ;; found in the repeated chord.  We don't need to look for
  ;; articulations on individual events since they can't actually get
  ;; into a repeat chord given its input syntax.

  (define (keep-element? m)
    (any (lambda (t) (music-is-of-type? m t))
	 event-types))
  (define origin (ly:music-property repeat-chord 'origin #f))
  (define (set-origin! l)
    (if origin
	(for-each (lambda (m) (set! (ly:music-property m 'origin) origin)) l))
    l)

  (for-each
   (lambda (field)
     (for-each (lambda (e)
		 (for-each (lambda (x)
			     (set! event-types (delq x event-types)))
			   (ly:music-property e 'types)))
	       (ly:music-property repeat-chord field)))
   '(elements articulations))

  ;; now treat the elements
  (set! (ly:music-property repeat-chord 'elements)
	(let ((elts
	       (set-origin! (ly:music-deep-copy
			     (filter keep-element?
				     (ly:music-property original-chord
							'elements))))))
	  (for-each
	   (lambda (m)
	     (let ((arts (ly:music-property m 'articulations)))
	       (if (pair? arts)
		   (set! (ly:music-property m 'articulations)
			 (set-origin! (filter! keep-element? arts))))
	       (if (ly:duration? (ly:music-property m 'duration))
		   (set! (ly:music-property m 'duration) duration))))
	   elts)
	  (append! elts (ly:music-property repeat-chord 'elements))))
  (let ((arts (filter keep-element?
		      (ly:music-property original-chord
					 'articulations))))
    (if (pair? arts)
	(set! (ly:music-property repeat-chord 'articulations)
	      (append!
	       (set-origin! (ly:music-deep-copy arts))
	       (ly:music-property repeat-chord 'articulations))))))


(define-public (expand-repeat-chords! event-types music)
  "Walks through @var{music} and fills repeated chords (notable by
having a duration in @code{duration}) with the notes from their
respective predecessor chord."
  (let loop ((music music) (last-chord #f))
    (if (music-is-of-type? music 'event-chord)
	(let ((chord-repeat (ly:music-property music 'duration)))
	  (cond
	   ((not (ly:duration? chord-repeat))
	    (if (any (lambda (m) (ly:duration?
				  (ly:music-property m 'duration)))
		     (ly:music-property music 'elements))
		music
		last-chord))
	   (last-chord
	    (set! (ly:music-property music 'duration) '())
	    (copy-repeat-chord last-chord music chord-repeat event-types)
	    music)
	   (else
	    (ly:music-warning music (_ "Bad chord repetition"))
	    #f)))
	(let ((elt (ly:music-property music 'element)))
	  (fold loop (if (ly:music? elt) (loop elt last-chord) last-chord)
		(ly:music-property music 'elements)))))
  music)

;;; splitting chords into voices.
(define (voicify-list lst number)
  "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))))
	     'Bottom  (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"
  (let ((es (ly:music-property ch 'elements)))
    (set! (ly:music-property  ch 'elements)
	  (voicify-list (split-list-by-separator es music-separator?) 0))
    ch))

(define-public (voicify-music m)
  "Recursively split chords that are separated with @code{\\\\}."
  (if (not (ly:music? m))
      (ly:error (_ "music expected: ~S") m))
  (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-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))

(define-public (empty-music)
  (make-music 'Music))

;; Make a function that checks score element for being of a specific type.
(define-public (make-type-checker symbol)
  (lambda (elt)
    (grob::has-interface elt symbol)))

(define-public ((outputproperty-compatibility func sym val) grob g-context ao-context)
  (if (func grob)
      (set! (ly:grob-property grob sym) val)))


(define-public ((set-output-property grob-name symbol val)  grob grob-c context)
  "Usage example:
@code{\\applyoutput #(set-output-property 'Clef 'extra-offset '(0 . 1))}"
  (let ((meta (ly:grob-property grob 'meta)))
    (if (equal? (assoc-get 'name meta) grob-name)
	(set! (ly:grob-property grob symbol) val))))


(define-public (skip->rest mus)
  "Replace @var{mus} by @code{RestEvent} of the same duration if it is a
@code{SkipEvent}.  Useful for extracting parts from crowded scores."

  (if  (memq (ly:music-property mus 'name) '(SkipEvent SkipMusic))
   (make-music 'RestEvent 'duration (ly:music-property mus 'duration))
   mus))


(define-public (music-has-type music type)
  (memq type (ly:music-property music 'types)))

(define-public (music-clone music)
  (define (alist->args alist acc)
    (if (null? alist)
	acc
	(alist->args (cdr alist)
		     (cons (caar alist) (cons (cdar alist) acc)))))

  (apply
   make-music
   (ly:music-property music 'name)
   (alist->args (ly:music-mutable-properties music) '())))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; warn for bare chords at start.

(define-public (ly:music-message music msg)
  (let ((ip (ly:music-property music 'origin)))
    (if (ly:input-location? ip)
        (ly:input-message ip msg)
        (ly:message msg))))

(define-public (ly:music-warning music msg)
  (let ((ip (ly:music-property music 'origin)))
    (if (ly:input-location? ip)
        (ly:input-warning ip msg)
        (ly:warning msg))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; setting stuff for grace context.
;;

(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) '())))
    (vector-move-left! v 0 n nv 0)
    (vector-set! nv n x)
    nv))

(define (vector-map f v)
  "Map F over V.  This function returns nothing."
  (do ((n (vector-length v))
       (i 0 (+ i 1)))
      ((>= i n))
    (f (vector-ref v i))))

(define (vector-reverse-map f v)
  "Map F over V, N to 0 order.  This function returns nothing."
  (do ((i (- (vector-length v) 1) (- i 1)))
      ((< i 0))
    (f (vector-ref v i))))

(define-public (add-grace-property context-name grob sym val)
  "Set @var{sym}=@var{val} for @var{grob} in @var{context-name}."
  (define (set-prop context)
    (let* ((where (ly:context-property-where-defined context 'graceSettings))
	   (current (ly:context-property where 'graceSettings))
	   (new-settings (append current
				 (list (list context-name grob sym val)))))
      (ly:context-set-property! where 'graceSettings new-settings)))
  (context-spec-music (make-apply-context set-prop) 'Voice))

(define-public (remove-grace-property context-name grob sym)
  "Remove all @var{sym} for @var{grob} in @var{context-name}."
  (define (sym-grob-context? property sym grob context-name)
    (and (eq? (car property) context-name)
         (eq? (cadr property) grob)
         (eq? (caddr property) sym)))
  (define (delete-prop context)
    (let* ((where (ly:context-property-where-defined context 'graceSettings))
	   (current (ly:context-property where 'graceSettings))
           (prop-settings (filter
                            (lambda(x) (sym-grob-context? x sym grob context-name))
                            current))
	   (new-settings current))
      (for-each (lambda(x)
                 (set! new-settings (delete x new-settings)))
               prop-settings)
      (ly:context-set-property! where 'graceSettings new-settings)))
  (context-spec-music (make-apply-context delete-prop) 'Voice))



(defmacro-public def-grace-function (start stop . docstring)
  "Helper macro for defining grace music"
  `(define-music-function (parser location music) (ly:music?)
     ,@docstring
     (make-music 'GraceMusic
		 'origin location
		 'element (make-music 'SequentialMusic
				      'elements (list (ly:music-deep-copy ,start)
						      music
						      (ly:music-deep-copy ,stop))))))

(defmacro-public define-syntax-function (type args signature . body)
  "Helper macro for `ly:make-music-function'.
Syntax:
  (define-syntax-function result-type? (parser location arg1 arg2 ...) (arg1-type arg2-type ...)
    ...function body...)

argX-type can take one of the forms @code{predicate?} for mandatory
arguments satisfying the predicate, @code{(predicate?)} for optional
parameters of that type defaulting to @code{#f}, @code{@w{(predicate?
value)}} for optional parameters with a specified default
value (evaluated at definition time).  An optional parameter can be
omitted in a call only when it can't get confused with a following
parameter of different type.

Predicates with syntactical significance are @code{ly:pitch?},
@code{ly:duration?}, @code{ly:music?}, @code{markup?}.  Other
predicates require the parameter to be entered as Scheme expression.

@code{result-type?} can specify a default in the same manner as
predicates, to be used in case of a type error in arguments or
result."

  (set! signature (map (lambda (pred)
			 (if (pair? pred)
			     `(cons ,(car pred)
				    ,(and (pair? (cdr pred)) (cadr pred)))
			     pred))
		       (cons type signature)))
  (if (and (pair? body) (pair? (car body)) (eqv? '_i (caar body)))
      ;; When the music function definition contains a i10n doc string,
      ;; (_i "doc string"), keep the literal string only
      (let ((docstring (cadar body))
	    (body (cdr body)))
	`(ly:make-music-function (list ,@signature)
				 (lambda ,args
				   ,docstring
				   ,@body)))
      `(ly:make-music-function (list ,@signature)
			       (lambda ,args
				 ,@body))))

(defmacro-public define-music-function rest
  "Defining macro returning music functions.
Syntax:
  (define-music-function (parser location arg1 arg2 ...) (arg1-type? arg2-type? ...)
    ...function body...)

argX-type can take one of the forms @code{predicate?} for mandatory
arguments satisfying the predicate, @code{(predicate?)} for optional
parameters of that type defaulting to @code{#f}, @code{@w{(predicate?
value)}} for optional parameters with a specified default
value (evaluated at definition time).  An optional parameter can be
omitted in a call only when it can't get confused with a following
parameter of different type.

Predicates with syntactical significance are @code{ly:pitch?},
@code{ly:duration?}, @code{ly:music?}, @code{markup?}.  Other
predicates require the parameter to be entered as Scheme expression.

Must return a music expression.  The @code{origin} is automatically
set to the @code{location} parameter."

  `(define-syntax-function (ly:music? (make-music 'Music 'void #t)) ,@rest))


(defmacro-public define-scheme-function rest
  "Defining macro returning Scheme functions.
Syntax:
  (define-scheme-function (parser location arg1 arg2 ...) (arg1-type? arg2-type? ...)
    ...function body...)

argX-type can take one of the forms @code{predicate?} for mandatory
arguments satisfying the predicate, @code{(predicate?)} for optional
parameters of that type defaulting to @code{#f}, @code{@w{(predicate?
value)}} for optional parameters with a specified default
value (evaluated at definition time).  An optional parameter can be
omitted in a call only when it can't get confused with a following
parameter of different type.

Predicates with syntactical significance are @code{ly:pitch?},
@code{ly:duration?}, @code{ly:music?}, @code{markup?}.  Other
predicates require the parameter to be entered as Scheme expression.

Can return arbitrary expressions.  If a music expression is returned,
its @code{origin} is automatically set to the @code{location}
parameter."

  `(define-syntax-function scheme? ,@rest))

(defmacro-public define-void-function rest
  "This defines a Scheme function like @code{define-scheme-function} with
void return value (i.e., what most Guile functions with `unspecified'
value return).  Use this when defining functions for executing actions
rather than returning values, to keep Lilypond from trying to interpret
the return value."
  `(define-syntax-function (void? *unspecified*) ,@rest *unspecified*))

(defmacro-public define-event-function rest
  "Defining macro returning event functions.
Syntax:
  (define-event-function (parser location arg1 arg2 ...) (arg1-type? arg2-type? ...)
    ...function body...)

argX-type can take one of the forms @code{predicate?} for mandatory
arguments satisfying the predicate, @code{(predicate?)} for optional
parameters of that type defaulting to @code{#f}, @code{@w{(predicate?
value)}} for optional parameters with a specified default
value (evaluated at definition time).  An optional parameter can be
omitted in a call only when it can't get confused with a following
parameter of different type.

Predicates with syntactical significance are @code{ly:pitch?},
@code{ly:duration?}, @code{ly:music?}, @code{markup?}.  Other
predicates require the parameter to be entered as Scheme expression.

Must return an event expression.  The @code{origin} is automatically
set to the @code{location} parameter."

  `(define-syntax-function (ly:event? (make-music 'Event 'void #t)) ,@rest))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define-public (cue-substitute quote-music)
  "Must happen after @code{quote-substitute}."

  (if (vector? (ly:music-property quote-music 'quoted-events))
      (let* ((dir (ly:music-property quote-music 'quoted-voice-direction))
	     (clef (ly:music-property quote-music 'quoted-music-clef #f))
	     (main-voice (case dir ((1) 1) ((-1) 0) (else #f)))
	     (cue-voice (and main-voice (- 1 main-voice)))
	     (main-music (ly:music-property quote-music 'element))
	     (return-value quote-music))

	(if main-voice
	    (set! (ly:music-property quote-music 'element)
		  (make-sequential-music
		   (list
		    (make-voice-props-override main-voice)
		    main-music
		    (make-voice-props-revert)))))

	;; if we have stem dirs, change both quoted and main music
	;; to have opposite stems.

	;; cannot context-spec Quote-music, since context
	;; for the quotes is determined in the iterator.

	(make-sequential-music
	 (delq! #f
		(list
		 (and clef (make-cue-clef-set clef))

		 ;; Need to establish CueVoice context even in #CENTER case
		 (context-spec-music
		  (if cue-voice
		      (make-voice-props-override cue-voice)
		      (make-music 'Music))
		  'CueVoice "cue")
		 quote-music
		 (and cue-voice
		      (context-spec-music
		       (make-voice-props-revert) 'CueVoice "cue"))
		 (and clef (make-cue-clef-unset))))))
      quote-music))

(define-public ((quote-substitute quote-tab) music)
  (let* ((quoted-name (ly:music-property music 'quoted-music-name))
	 (quoted-vector (and (string? quoted-name)
			     (hash-ref quote-tab quoted-name #f))))


    (if (string? quoted-name)
	(if (vector? quoted-vector)
	    (begin
	      (set! (ly:music-property music 'quoted-events) quoted-vector)
	      (set! (ly:music-property music 'iterator-ctor)
		    ly:quote-iterator::constructor))
	    (ly:music-warning music (ly:format (_ "cannot find quoted music: `~S'") quoted-name))))
    music))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; switch it on here, so parsing and init isn't checked (too slow!)
;;
;; automatic music transformations.

(define (switch-on-debugging m)
  (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 (make-duration-of-length moment)
 "Make duration of the given @code{moment} length."
 (ly:make-duration 0 0
  (ly:moment-main-numerator moment)
  (ly:moment-main-denominator moment)))

(define (make-skipped moment bool)
 "Depending on BOOL, set or unset skipTypesetting,
then make SkipMusic of the given MOMENT length, and
then revert skipTypesetting."
 (make-sequential-music
  (list
   (context-spec-music (make-property-set 'skipTypesetting bool)
    'Score)
   (make-music 'SkipMusic 'duration
    (make-duration-of-length moment))
   (context-spec-music (make-property-set 'skipTypesetting (not bool))
    'Score))))

(define (skip-as-needed music parser)
  "Replace MUSIC by
 << {  \\set skipTypesetting = ##f
 LENGTHOF(\\showFirstLength)
 \\set skipTypesetting = ##t
 LENGTHOF(\\showLastLength) }
 MUSIC >>
 if appropriate.

 When only showFirstLength is set,
 the 'length property of the music is
 overridden to speed up compiling."
  (let*
      ((show-last (ly:parser-lookup parser 'showLastLength))
       (show-first (ly:parser-lookup parser 'showFirstLength))
       (show-last-length (and (ly:music? show-last)
			      (ly:music-length show-last)))
       (show-first-length (and (ly:music? show-first)
			       (ly:music-length show-first)))
       (orig-length (ly:music-length music)))

    ;;FIXME: if using either showFirst- or showLastLength,
    ;; make sure that skipBars is not set.

    (cond

     ;; both properties may be set.
     ((and show-first-length show-last-length)
      (let
          ((skip-length (ly:moment-sub orig-length show-last-length)))
        (make-simultaneous-music
         (list
          (make-sequential-music
           (list
            (make-skipped skip-length #t)
            ;; let's draw a separator between the beginning and the end
            (context-spec-music (make-property-set 'whichBar "||")
                                'Timing)))
          (make-skipped show-first-length #f)
          music))))

     ;; we may only want to print the last length
     (show-last-length
      (let
          ((skip-length (ly:moment-sub orig-length show-last-length)))
        (make-simultaneous-music
         (list
          (make-skipped skip-length #t)
          music))))

     ;; we may only want to print the beginning; in this case
     ;; only the first length will be processed (much faster).
     (show-first-length
      ;; the first length must not exceed the original length.
      (if (ly:moment<? show-first-length orig-length)
          (set! (ly:music-property music 'length)
                show-first-length))
      music)

     (else music))))


(define-public toplevel-music-functions
  (list
   (lambda (music parser) (expand-repeat-chords!
			   (cons 'rhythmic-event
				 (ly:parser-lookup parser '$chord-repeat-events))
			   music))
   (lambda (music parser) (voicify-music music))
   (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))

   (lambda (x parser)
     (skip-as-needed x parser)
   )))

;;;;;;;;;;
;;; general purpose music functions

(define (shift-octave pitch octave-shift)
  (_i "Add @var{octave-shift} to the octave of @var{pitch}.")
  (ly:make-pitch
     (+ (ly:pitch-octave pitch) octave-shift)
     (ly:pitch-notename pitch)
     (ly:pitch-alteration pitch)))


;;;;;;;;;;;;;;;;;
;; lyrics

(define (apply-durations lyric-music durations)
  (define (apply-duration music)
    (if (and (not (equal? (ly:music-length music) ZERO-MOMENT))
	     (ly:duration?  (ly:music-property music 'duration)))
	(begin
	  (set! (ly:music-property music 'duration) (car durations))
	  (set! durations (cdr durations)))))

  (music-map apply-duration lyric-music))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; accidentals

(define (recent-enough? bar-number alteration-def laziness)
  (or (number? alteration-def)
      (equal? laziness #t)
      (<= bar-number (+ (cadr alteration-def) laziness))))

(define (accidental-invalid? alteration-def)
  "Checks an alteration entry for being invalid.

Non-key alterations are invalidated when tying into the next bar or
when there is a clef change, since neither repetition nor cancellation
can be omitted when the same note occurs again.

Returns @code{#f} or the reason for the invalidation, a symbol."
  (let* ((def (if (pair? alteration-def)
		  (car alteration-def)
		  alteration-def)))
    (and (symbol? def) def)))

(define (extract-alteration alteration-def)
  (cond ((number? alteration-def)
	 alteration-def)
	((pair? alteration-def)
	 (car alteration-def))
	(else 0)))

(define (check-pitch-against-signature context pitch barnum laziness octaveness)
  "Checks the need for an accidental and a @q{restore} accidental against
@code{localKeySignature}.  The @var{laziness} is the number of measures
for which reminder accidentals are used (i.e., if @var{laziness} is zero,
only cancel accidentals in the same measure; if @var{laziness} is three,
we cancel accidentals up to three measures after they first appear.
@var{octaveness} is either @code{'same-octave} or @code{'any-octave} and
specifies whether accidentals should be canceled in different octaves."
  (let* ((ignore-octave (cond ((equal? octaveness 'any-octave) #t)
			      ((equal? octaveness 'same-octave) #f)
			      (else
			       (ly:warning (_ "Unknown octaveness type: ~S ") octaveness)
			       (ly:warning (_ "Defaulting to 'any-octave."))
			       #t)))
	 (key-sig (ly:context-property context 'keySignature))
	 (local-key-sig (ly:context-property context 'localKeySignature))
	 (notename (ly:pitch-notename pitch))
	 (octave (ly:pitch-octave pitch))
	 (pitch-handle (cons octave notename))
	 (need-restore #f)
	 (need-accidental #f)
	 (previous-alteration #f)
	 (from-other-octaves #f)
	 (from-same-octave (assoc-get pitch-handle local-key-sig))
	 (from-key-sig (or (assoc-get notename local-key-sig)

    ;; If no key signature match is found from localKeySignature, we may have a custom
    ;; type with octave-specific entries of the form ((octave . pitch) alteration)
    ;; instead of (pitch . alteration).  Since this type cannot coexist with entries in
    ;; localKeySignature, try extracting from keySignature instead.
			   (assoc-get pitch-handle key-sig))))

    ;; loop through localKeySignature to search for a notename match from other octaves
    (let loop ((l local-key-sig))
      (if (pair? l)
	  (let ((entry (car l)))
	    (if (and (pair? (car entry))
		     (= (cdar entry) notename))
		(set! from-other-octaves (cdr entry))
		(loop (cdr l))))))

    ;; find previous alteration-def for comparison with pitch
    (cond
     ;; from same octave?
     ((and (not ignore-octave)
	   from-same-octave
	   (recent-enough? barnum from-same-octave laziness))
      (set! previous-alteration from-same-octave))

     ;; from any octave?
     ((and ignore-octave
	   from-other-octaves
	   (recent-enough? barnum from-other-octaves laziness))
      (set! previous-alteration from-other-octaves))

     ;; not recent enough, extract from key signature/local key signature
     (from-key-sig
      (set! previous-alteration from-key-sig)))

    (if (accidental-invalid? previous-alteration)
	(set! need-accidental #t)

	(let* ((prev-alt (extract-alteration previous-alteration))
	       (this-alt (ly:pitch-alteration pitch)))

	  (if (not (= this-alt prev-alt))
	      (begin
		(set! need-accidental #t)
		(if (and (not (= this-alt 0))
			 (and (< (abs this-alt) (abs prev-alt))
			     (> (* prev-alt this-alt) 0)))
		    (set! need-restore #t))))))

    (cons need-restore need-accidental)))

(define-public ((make-accidental-rule octaveness laziness) context pitch barnum measurepos)
  "Create an accidental rule that makes its decision based on the octave of
the note and a laziness value.

@var{octaveness} is either @code{'same-octave} or @code{'any-octave} and
defines whether the rule should respond to accidental changes in other
octaves than the current.  @code{'same-octave} is the normal way to typeset
accidentals -- an accidental is made if the alteration is different from the
last active pitch in the same octave.  @code{'any-octave} looks at the last
active pitch in any octave.

@var{laziness} states over how many bars an accidental should be remembered.
@code{0}@tie{}is the default -- accidental lasts over 0@tie{}bar lines, that
is, to the end of current measure.  A positive integer means that the
accidental lasts over that many bar lines.  @w{@code{-1}} is `forget
immediately', that is, only look at key signature.  @code{#t} is `forever'."

  (check-pitch-against-signature context pitch barnum laziness octaveness))

(define (key-entry-notename entry)
  "Return the pitch of an entry in localKeySignature.  The entry is either of the form
  '(notename . alter) or '((octave . notename) . (alter barnum . measurepos))."
  (if (number? (car entry))
      (car entry)
      (cdar entry)))

(define (key-entry-octave entry)
  "Return the octave of an entry in localKeySignature (or #f if the entry does not have
  an octave)."
  (and (pair? (car entry)) (caar entry)))

(define (key-entry-bar-number entry)
  "Return the bar number of an entry in localKeySignature (or #f if the entry does not
  have a bar number)."
  (and (pair? (car entry)) (caddr entry)))

(define (key-entry-measure-position entry)
  "Return the measure position of an entry in localKeySignature (or #f if the entry does
  not have a measure position)."
  (and (pair? (car entry)) (cdddr entry)))

(define (key-entry-alteration entry)
  "Return the alteration of an entry in localKeySignature.

For convenience, returns @code{0} if entry is @code{#f}."
  (if entry
      (if (number? (car entry))
	  (cdr entry)
	  (cadr entry))
      0))

(define-public (find-pitch-entry keysig pitch accept-global accept-local)
  "Return the first entry in @var{keysig} that matches @var{pitch}.
@var{accept-global} states whether key signature entries should be included.
@var{accept-local} states whether local accidentals should be included.
If no matching entry is found, @var{#f} is returned."
  (and (pair? keysig)
       (let* ((entry (car keysig))
	      (entryoct (key-entry-octave entry))
	      (entrynn (key-entry-notename entry))
	      (nn (ly:pitch-notename pitch)))
	 (if (and (equal? nn entrynn)
		  (or (not entryoct)
		      (= entryoct (ly:pitch-octave pitch)))
		  (if (key-entry-bar-number entry)
		      accept-local
		      accept-global))
	     entry
	     (find-pitch-entry (cdr keysig) pitch accept-global accept-local)))))

(define-public (neo-modern-accidental-rule context pitch barnum measurepos)
  "An accidental rule that typesets an accidental if it differs from the
key signature @emph{and} does not directly follow a note on the same
staff line.  This rule should not be used alone because it does neither
look at bar lines nor different accidentals at the same note name."
  (let* ((keysig (ly:context-property context 'localKeySignature))
	 (entry (find-pitch-entry keysig pitch #t #t)))
    (if (not entry)
	(cons #f #f)
	(let* ((global-entry (find-pitch-entry keysig pitch #t #f))
	       (key-acc (key-entry-alteration global-entry))
	       (acc (ly:pitch-alteration pitch))
	       (entrymp (key-entry-measure-position entry))
	       (entrybn (key-entry-bar-number entry)))
	  (cons #f (not (or (equal? acc key-acc)
			    (and (equal? entrybn barnum) (equal? entrymp measurepos)))))))))

(define-public (teaching-accidental-rule context pitch barnum measurepos)
  "An accidental rule that typesets a cautionary accidental if it is
included in the key signature @emph{and} does not directly follow a note
on the same staff line."
  (let* ((keysig (ly:context-property context 'localKeySignature))
	 (entry (find-pitch-entry keysig pitch #t #t)))
    (if (not entry)
	(cons #f #f)
	(let* ((entrymp (key-entry-measure-position entry))
	       (entrybn (key-entry-bar-number entry)))
	  (cons #f (not (and (equal? entrybn barnum) (equal? entrymp measurepos))))))))

(define-public (set-accidentals-properties extra-natural
					   auto-accs auto-cauts
					   context)
  (context-spec-music
   (make-sequential-music
    (append (if (boolean? extra-natural)
		(list (make-property-set 'extraNatural extra-natural))
		'())
	    (list (make-property-set 'autoAccidentals auto-accs)
		  (make-property-set 'autoCautionaries auto-cauts))))
   context))

(define-public (set-accidental-style style . rest)
  "Set accidental style to @var{style}.  Optionally take a context
argument, e.g. @code{'Staff} or @code{'Voice}.  The context defaults
to @code{Staff}, except for piano styles, which use @code{GrandStaff}
as a context."
  (let ((context (if (pair? rest)
		     (car rest) 'Staff))
	(pcontext (if (pair? rest)
		      (car rest) 'GrandStaff)))
    (cond
      ;; accidentals as they were common in the 18th century.
      ((equal? style 'default)
       (set-accidentals-properties #t
				   `(Staff ,(make-accidental-rule 'same-octave 0))
				   '()
				   context))
      ;; accidentals from one voice do NOT get canceled in other voices
      ((equal? style 'voice)
       (set-accidentals-properties #t
				   `(Voice ,(make-accidental-rule 'same-octave 0))
				   '()
				   context))
      ;; accidentals as suggested by Kurt Stone, Music Notation in the 20th century.
      ;; This includes all the default accidentals, but accidentals also needs canceling
      ;; in other octaves and in the next measure.
      ((equal? style 'modern)
       (set-accidentals-properties #f
				   `(Staff ,(make-accidental-rule 'same-octave 0)
					   ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1))
				   '()
				   context))
      ;; the accidentals that Stone adds to the old standard as cautionaries
      ((equal? style 'modern-cautionary)
       (set-accidentals-properties #f
				   `(Staff ,(make-accidental-rule 'same-octave 0))
				   `(Staff ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1))
				   context))
      ;; same as modern, but accidentals different from the key signature are always
      ;; typeset - unless they directly follow a note of the same pitch.
      ((equal? style 'neo-modern)
       (set-accidentals-properties #f
				   `(Staff ,(make-accidental-rule 'same-octave 0)
					   ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
				           ,neo-modern-accidental-rule)
				   '()
				   context))
      ((equal? style 'neo-modern-cautionary)
       (set-accidentals-properties #f
				   `(Staff ,(make-accidental-rule 'same-octave 0))
				   `(Staff ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
				           ,neo-modern-accidental-rule)
				   context))
      ((equal? style 'neo-modern-voice)
       (set-accidentals-properties #f
				   `(Voice ,(make-accidental-rule 'same-octave 0)
					   ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
					   ,neo-modern-accidental-rule
				     Staff ,(make-accidental-rule 'same-octave 0)
					   ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
				      ,neo-modern-accidental-rule)
				   '()
				   context))
      ((equal? style 'neo-modern-voice-cautionary)
       (set-accidentals-properties #f
				   `(Voice ,(make-accidental-rule 'same-octave 0))
				   `(Voice ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
					   ,neo-modern-accidental-rule
				     Staff ,(make-accidental-rule 'same-octave 0)
					   ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
					   ,neo-modern-accidental-rule)
				   context))
      ;; Accidentals as they were common in dodecaphonic music with no tonality.
      ;; Each note gets one accidental.
      ((equal? style 'dodecaphonic)
       (set-accidentals-properties #f
				   `(Staff ,(lambda (c p bn mp) '(#f . #t)))
				   '()
				   context))
      ;; Multivoice accidentals to be read both by musicians playing one voice
      ;; and musicians playing all voices.
      ;; Accidentals are typeset for each voice, but they ARE canceled across voices.
      ((equal? style 'modern-voice)
       (set-accidentals-properties  #f
				    `(Voice ,(make-accidental-rule 'same-octave 0)
					    ,(make-accidental-rule 'any-octave 0)
					    ,(make-accidental-rule 'same-octave 1)
				      Staff ,(make-accidental-rule 'same-octave 0)
					    ,(make-accidental-rule 'any-octave 0)
					    ,(make-accidental-rule 'same-octave 1))
				    '()
				    context))
      ;; same as modernVoiceAccidental eccept that all special accidentals are typeset
      ;; as cautionaries
      ((equal? style 'modern-voice-cautionary)
       (set-accidentals-properties #f
				   `(Voice ,(make-accidental-rule 'same-octave 0))
				   `(Voice ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
				     Staff ,(make-accidental-rule 'same-octave 0)
				           ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1))
				   context))
      ;; stone's suggestions for accidentals on grand staff.
      ;; Accidentals are canceled across the staves in the same grand staff as well
      ((equal? style 'piano)
       (set-accidentals-properties #f
				   `(Staff ,(make-accidental-rule 'same-octave 0)
					   ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
				     GrandStaff
				           ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1))
				   '()
				   pcontext))
      ((equal? style 'piano-cautionary)
       (set-accidentals-properties #f
				   `(Staff ,(make-accidental-rule 'same-octave 0))
				   `(Staff ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1)
				     GrandStaff
				           ,(make-accidental-rule 'any-octave 0)
					   ,(make-accidental-rule 'same-octave 1))
				   pcontext))

      ;; same as modern, but cautionary accidentals are printed for all sharp or flat
      ;; tones specified by the key signature.
       ((equal? style 'teaching)
       (set-accidentals-properties #f
				    `(Staff ,(make-accidental-rule 'same-octave 0))
				    `(Staff ,(make-accidental-rule 'same-octave 1)
				           ,teaching-accidental-rule)
				   context))

      ;; do not set localKeySignature when a note alterated differently from
      ;; localKeySignature is found.
      ;; Causes accidentals to be printed at every note instead of
      ;; remembered for the duration of a measure.
      ;; accidentals not being remembered, causing accidentals always to
      ;; be typeset relative to the time signature
      ((equal? style 'forget)
       (set-accidentals-properties '()
				   `(Staff ,(make-accidental-rule 'same-octave -1))
				   '()
				   context))
      ;; Do not reset the key at the start of a measure.  Accidentals will be
      ;; printed only once and are in effect until overridden, possibly many
      ;; measures later.
      ((equal? style 'no-reset)
       (set-accidentals-properties '()
				   `(Staff ,(make-accidental-rule 'same-octave #t))
				   '()
				   context))
      (else
       (ly:warning (_ "unknown accidental style: ~S") style)
       (make-sequential-music '())))))

(define-public (invalidate-alterations context)
  "Invalidate alterations in @var{context}.

Elements of @code{'localKeySignature} corresponding to local
alterations of the key signature have the form
@code{'((octave . notename) . (alter barnum . measurepos))}.
Replace them with a version where @code{alter} is set to @code{'clef}
to force a repetition of accidentals.

Entries that conform with the current key signature are not invalidated."
  (let* ((keysig (ly:context-property context 'keySignature)))
    (set! (ly:context-property context 'localKeySignature)
	  (map-in-order
	   (lambda (entry)
	     (let* ((localalt (key-entry-alteration entry))
		    (localoct (key-entry-octave entry)))
	       (if (or (accidental-invalid? localalt)
		       (not localoct)
		       (= localalt
			  (key-entry-alteration
			   (find-pitch-entry
			    keysig
			    (ly:make-pitch localoct
					   (key-entry-notename entry)
					   0)
			    #t #t))))
		   entry
		   (cons (car entry) (cons 'clef (cddr entry))))))
	   (ly:context-property context 'localKeySignature)))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define-public (skip-of-length mus)
  "Create a skip of exactly the same length as @var{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 multi-measure rest of exactly the same length as @var{mus}."

  (let* ((skip
	  (make-multi-measure-rest
	   (ly:make-duration 0 0) '())))
    (ly:music-compress skip (ly:music-length mus))
    skip))

(define-public (pitch-of-note event-chord)
  (let ((evs (filter (lambda (x)
		       (music-has-type x 'note-event))
		     (ly:music-property event-chord 'elements))))

    (and (pair? evs)
	 (ly:music-property (car evs) 'pitch))))

(define-public (duration-of-note event-chord)
  (cond
   ((pair? event-chord)
    (or (duration-of-note (car event-chord))
	(duration-of-note (cdr event-chord))))
   ((ly:music? event-chord)
    (let ((dur (ly:music-property event-chord 'duration)))
      (if (ly:duration? dur)
	  dur
	  (duration-of-note (ly:music-property event-chord 'elements)))))
   (else #f)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define-public (map-some-music map? music)
  "Walk through @var{music}, transform all elements calling @var{map?}
and only recurse if this returns @code{#f}."
  (let loop ((music music))
    (or (map? music)
	(let ((elt (ly:music-property music 'element))
	      (elts (ly:music-property music 'elements))
	      (arts (ly:music-property music 'articulations)))
	  (if (ly:music? elt)
	      (set! (ly:music-property music 'element)
		    (loop elt)))
	  (if (pair? elts)
	      (set! (ly:music-property music 'elements)
		    (map loop elts)))
	  (if (pair? arts)
	      (set! (ly:music-property music 'articulations)
		    (map loop arts)))
	  music))))

(define-public (for-some-music stop? music)
  "Walk through @var{music}, process all elements calling @var{stop?}
and only recurse if this returns @code{#f}."
  (let loop ((music music))
    (if (not (stop? music))
	(let ((elt (ly:music-property music 'element)))
	  (if (ly:music? elt)
	      (loop elt))
	  (for-each loop (ly:music-property music 'elements))
	  (for-each loop (ly:music-property music 'articulations))))))

(define-public (fold-some-music pred? proc init music)
  "This works recursively on music like @code{fold} does on a list,
calling @samp{(@var{pred?} music)} on every music element.  If
@code{#f} is returned for an element, it is processed recursively
with the same initial value of @samp{previous}, otherwise
@samp{(@var{proc} music previous)} replaces @samp{previous}
and no recursion happens.
The top @var{music} is processed using @var{init} for @samp{previous}."
  (let loop ((music music) (previous init))
    (if (pred? music)
	(proc music previous)
	(fold loop
	      (fold loop
		    (let ((elt (ly:music-property music 'element)))
		      (if (null? elt)
			  previous
			  (loop elt previous)))
		    (ly:music-property music 'elements))
	      (ly:music-property music 'articulations)))))

(define-public (extract-music music pred?)
  "Return a flat list of all music matching @var{pred?} inside of
@var{music}, not recursing into matches themselves."
  (reverse! (fold-some-music pred? cons '() music)))

(define-public (extract-named-music music music-name)
  "Return a flat list of all music named @var{music-name} (either a
single event symbol or a list of alternatives) inside of @var{music},
not recursing into matches themselves."
  (extract-music
   music
   (if (cheap-list? music-name)
       (lambda (m) (memq (ly:music-property m 'name) music-name))
       (lambda (m) (eq? (ly:music-property m 'name) music-name)))))

(define-public (extract-typed-music music type)
  "Return a flat list of all music with @var{type} (either a single
type symbol or a list of alternatives) inside of @var{music}, not
recursing into matches themselves."
  (extract-music
   music
   (if (cheap-list? type)
       (lambda (m)
	 (any (lambda (t) (music-is-of-type? m t)) type))
       (lambda (m) (music-is-of-type? m type)))))

(define*-public (event-chord-wrap! music #:optional parser)
  "Wrap isolated rhythmic events and non-postevent events in
@var{music} inside of an @code{EventChord}.  If the optional
@var{parser} argument is given, chord repeats @samp{q} are expanded
using the default settings.  Otherwise, you need to cater for them
yourself."
  (map-some-music
   (lambda (m)
     (cond ((music-is-of-type? m 'event-chord)
	    (if (pair? (ly:music-property m 'articulations))
		(begin
		  (set! (ly:music-property m 'elements)
			(append (ly:music-property m 'elements)
				(ly:music-property m 'articulations)))
		  (set! (ly:music-property m 'articulations) '())))
	    m)
	   ((music-is-of-type? m 'rhythmic-event)
	    (let ((arts (ly:music-property m 'articulations)))
	      (if (pair? arts)
		  (set! (ly:music-property m 'articulations) '()))
	      (make-event-chord (cons m arts))))
	   (else #f)))
   (if parser
       (expand-repeat-chords!
	(cons 'rhythmic-event
	      (ly:parser-lookup parser '$chord-repeat-events))
	music)
       music)))

(define-public (event-chord-notes event-chord)
  "Return a list of all notes from @var{event-chord}."
  (filter
    (lambda (m) (eq? 'NoteEvent (ly:music-property m 'name)))
    (ly:music-property event-chord 'elements)))

(define-public (event-chord-pitches event-chord)
  "Return a list of all pitches from @var{event-chord}."
  (map (lambda (x) (ly:music-property x 'pitch))
       (event-chord-notes event-chord)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; The following functions are all associated with the crossStaff
;  function

(define (close-enough? x y)
  "Values are close enough to ignore the difference"
   (< (abs (- x y)) 0.0001))

(define (extent-combine extents)
  "Combine a list of extents"
  (if (pair? (cdr extents))
      (interval-union (car extents) (extent-combine (cdr extents)))
      (car extents)))

(define ((stem-connectable? ref root) stem)
  "Check if the stem is connectable to the root"
  ; The root is always connectable to itself
  (or (eq? root stem)
      (and
      ; Horizontal positions of the stems must be almost the same
        (close-enough? (car (ly:grob-extent root ref X))
          (car (ly:grob-extent stem ref X)))
        ; The stem must be in the direction away from the root's notehead
        (positive? (* (ly:grob-property root 'direction)
                     (- (car (ly:grob-extent stem ref Y))
                       (car (ly:grob-extent root ref Y))))))))

(define (stem-span-stencil span)
  "Connect stems if we have at least one stem connectable to the root"
  (let* ((system (ly:grob-system span))
          (root (ly:grob-parent span X))
          (stems (filter (stem-connectable? system root)
                         (ly:grob-object span 'stems))))
     (if (<= 2 (length stems))
         (let* ((yextents (map (lambda (st)
                                 (ly:grob-extent st system Y)) stems))
                (yextent (extent-combine yextents))
                (layout (ly:grob-layout root))
                (blot (ly:output-def-lookup layout 'blot-diameter)))
           ; Hide spanned stems
           (map (lambda (st)
                  (set! (ly:grob-property st 'transparent) #t))
             stems)
           ; Draw a nice looking stem with rounded corners
           (ly:round-filled-box (ly:grob-extent root root X) yextent blot))
         ; Nothing to connect, don't draw the span
         #f)))

(define ((make-stem-span! stems trans) root)
  "Create a stem span as a child of the cross-staff stem (the root)"
  (let ((span (ly:engraver-make-grob trans 'Stem '())))
    (ly:grob-set-parent! span X root)
    (set! (ly:grob-object span 'stems) stems)
    ; Suppress positioning, the stem code is confused by this weird stem
    (set! (ly:grob-property span 'X-offset) 0)
    (set! (ly:grob-property span 'stencil) stem-span-stencil)))

(define-public (cross-staff-connect stem)
  "Set cross-staff property of the stem to this function to connect it to
other stems automatically"
   #t)

(define (stem-is-root? stem)
  "Check if automatic connecting of the stem was requested.  Stems connected
to cross-staff beams are cross-staff, but they should not be connected to
other stems just because of that."
  (eq? cross-staff-connect (ly:grob-property-data stem 'cross-staff)))

(define (make-stem-spans! ctx stems trans)
  "Create stem spans for cross-staff stems"
  ; Cannot do extensive checks here, just make sure there are at least
  ; two stems at this musical moment
  (if (<= 2 (length stems))
    (let ((roots (filter stem-is-root? stems)))
    (map (make-stem-span! stems trans) roots))))

(define-public (Span_stem_engraver ctx)
  "Connect cross-staff stems to the stems above in the system"
  (let ((stems '()))
    (make-engraver
      ; Record all stems for the given moment
      (acknowledgers
        ((stem-interface trans grob source)
        (set! stems (cons grob stems))))
      ; Process stems and reset the stem list to empty
      ((process-acknowledged trans)
        (make-stem-spans! ctx stems trans)
        (set! stems '())))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The following is used by the alterBroken function.

(define-public ((value-for-spanner-piece arg) grob)
  "Associate a piece of broken spanner @var{grob} with an element
of list @var{arg}."
  (let* ((orig (ly:grob-original grob))
         (siblings (ly:spanner-broken-into orig)))

   (define (helper sibs arg)
     (if (null? arg)
         arg
         (if (eq? (car sibs) grob)
             (car arg)
             (helper (cdr sibs) (cdr arg)))))

   (if (>= (length siblings) 2)
       (helper siblings arg)
       (car arg))))