X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=scm%2Fpart-combiner.scm;h=58f7b303a8620ac63279d571aa577b3a8698828b;hb=47db9a3883d726ca53e2133a3b2298f78dd6a32e;hp=8c779a91ee19944affc53ee95d8848e5f1582724;hpb=5edacf4c1908d0fe988d0ef9b3d6a9820a1e8734;p=lilypond.git

diff --git a/scm/part-combiner.scm b/scm/part-combiner.scm
index 8c779a91ee..58f7b303a8 100644
--- a/scm/part-combiner.scm
+++ b/scm/part-combiner.scm
@@ -1,6 +1,6 @@
 ;;;; This file is part of LilyPond, the GNU music typesetter.
 ;;;;
-;;;; Copyright (C) 2004--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
+;;;; Copyright (C) 2004--2015 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
@@ -20,7 +20,7 @@
 
 (define-class <Voice-state> ()
   (event-list #:init-value '() #:accessor events #:init-keyword #:events)
-  (when-moment #:accessor when #:init-keyword #:when)
+  (when-moment #:accessor moment #:init-keyword #:moment)
   (tuning #:accessor tuning #:init-keyword #:tuning)
   (split-index #:accessor split-index)
   (vector-index)
@@ -32,7 +32,7 @@
   (spanner-state #:init-value '() #:accessor span-state))
 
 (define-method (write (x <Voice-state> ) file)
-  (display (when x) file)
+  (display (moment x) file)
   (display " evs = " file)
   (display (events x) file)
   (display " active = " file)
@@ -41,15 +41,21 @@
 
 (define-method (note-events (vs <Voice-state>))
   (define (f? x)
-    (equal? (ly:event-property	x 'class) 'note-event))
+    (ly:in-event-class? x 'note-event))
+  (filter f? (events vs)))
+
+(define-method (rest-and-skip-events (vs <Voice-state>))
+  (define (f? x)
+    (or (ly:in-event-class? x 'rest-event)
+        (ly:in-event-class? x 'skip-event)))
   (filter f? (events vs)))
 
 (define-method (previous-voice-state (vs <Voice-state>))
   (let ((i (slot-ref vs 'vector-index))
-	(v (slot-ref vs 'state-vector)))
+        (v (slot-ref vs 'state-vector)))
     (if (< 0 i)
-	(vector-ref v (1- i))
-	#f)))
+        (vector-ref v (1- i))
+        #f)))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
@@ -58,15 +64,15 @@
   (configuration #:init-value '() #:accessor configuration)
   ;; Allow overriding split configuration, takes precedence over configuration
   (forced-configuration #:init-value #f #:accessor forced-configuration)
-  (when-moment #:accessor when #:init-keyword #:when)
+  (when-moment #:accessor moment #:init-keyword #:moment)
   ;; voice-states are states starting with the Split-state or later
   ;;
   (is #:init-keyword #:voice-states #:accessor voice-states)
-  (synced  #:init-keyword #:synced #:init-value	 #f #:getter synced?))
+  (synced  #:init-keyword #:synced #:init-value  #f #:getter synced?))
 
 
 (define-method (write (x <Split-state> ) f)
-  (display (when x) f)
+  (display (moment x) f)
   (display " = " f)
   (display (configuration x) f)
   (if (synced? x)
@@ -82,13 +88,13 @@
 
 (define (make-voice-states evl)
   (let ((vec (list->vector (map (lambda (v)
-				  (make <Voice-state>
-				    #:when (caar v)
-				    #:tuning (cdar v)
-				    #:events (map car (cdr v))))
-				evl))))
+                                  (make <Voice-state>
+                                    #:moment (caar v)
+                                    #:tuning (cdar v)
+                                    #:events (map car (cdr v))))
+                                evl))))
     (do ((i 0 (1+ i)))
-	((= i (vector-length vec)) vec)
+        ((= i (vector-length vec)) vec)
       (slot-set! (vector-ref vec i) 'vector-index i)
       (slot-set! (vector-ref vec i) 'state-vector vec))))
 
@@ -99,29 +105,29 @@ Voice-state objects
 "
   (define (helper ss-idx ss-list idx1 idx2)
     (let* ((state1 (if (< idx1 (vector-length vs1)) (vector-ref vs1 idx1) #f))
-	   (state2 (if (< idx2 (vector-length vs2)) (vector-ref vs2 idx2) #f))
-	   (min (cond ((and state1 state2) (moment-min (when state1) (when state2)))
-		      (state1 (when state1))
-		      (state2 (when state2))
-		      (else #f)))
-	   (inc1 (if (and state1 (equal? min (when state1))) 1 0))
-	   (inc2 (if (and state2 (equal? min (when state2))) 1 0))
-	   (ss-object (if min
-			  (make <Split-state>
-			    #:when min
-			    #:voice-states (cons state1 state2)
-			    #:synced (= inc1 inc2))
-			  #f)))
+           (state2 (if (< idx2 (vector-length vs2)) (vector-ref vs2 idx2) #f))
+           (min (cond ((and state1 state2) (moment-min (moment state1) (moment state2)))
+                      (state1 (moment state1))
+                      (state2 (moment state2))
+                      (else #f)))
+           (inc1 (if (and state1 (equal? min (moment state1))) 1 0))
+           (inc2 (if (and state2 (equal? min (moment state2))) 1 0))
+           (ss-object (if min
+                          (make <Split-state>
+                            #:moment min
+                            #:voice-states (cons state1 state2)
+                            #:synced (= inc1 inc2))
+                          #f)))
       (if state1
-	  (set! (split-index state1) ss-idx))
+          (set! (split-index state1) ss-idx))
       (if state2
-	  (set! (split-index state2) ss-idx))
+          (set! (split-index state2) ss-idx))
       (if min
-	  (helper (1+ ss-idx)
-		  (cons ss-object ss-list)
-		  (+ idx1 inc1)
-		  (+ idx2 inc2))
-	  ss-list)))
+          (helper (1+ ss-idx)
+                  (cons ss-object ss-list)
+                  (+ idx1 inc1)
+                  (+ idx2 inc2))
+          ss-list)))
   (list->vector (reverse! (helper 0 '() 0  0) '())))
 
 (define (analyse-spanner-states voice-state-vec)
@@ -130,142 +136,155 @@ Voice-state objects
     "Analyse EVS at INDEX, given state ACTIVE."
 
     (define (analyse-tie-start active ev)
-      (if (equal? (ly:event-property ev 'class) 'tie-event)
-	  (acons 'tie (split-index (vector-ref voice-state-vec index))
-		 active)
-	  active))
+      (if (ly:in-event-class? ev 'tie-event)
+          (acons 'tie (split-index (vector-ref voice-state-vec index))
+                 active)
+          active))
 
     (define (analyse-tie-end active ev)
-      (if (equal? (ly:event-property ev 'class) 'note-event)
-	  (assoc-remove! active 'tie)
-	  active))
+      (if (ly:in-event-class? ev 'note-event)
+          (assoc-remove! active 'tie)
+          active))
 
     (define (analyse-absdyn-end active ev)
-      (if (or (equal? (ly:event-property ev 'class) 'absolute-dynamic-event)
-	      (and (equal? (ly:event-property ev 'class) 'crescendo-event)
-		   (equal? STOP (ly:event-property ev 'span-direction))))
-	  (assoc-remove! (assoc-remove! active 'cresc) 'decr)
-	  active))
+      (if (or (ly:in-event-class? ev 'absolute-dynamic-event)
+              (and (ly:in-event-class? ev 'span-dynamic-event)
+                   (equal? STOP (ly:event-property ev 'span-direction))))
+          (assoc-remove! (assoc-remove! active 'cresc) 'decr)
+          active))
 
     (define (active<? a b)
       (cond ((symbol<? (car a) (car b)) #t)
-	    ((symbol<? (car b) (car b)) #f)
-	    (else (< (cdr a) (cdr b)))))
+            ((symbol<? (car b) (car a)) #f)
+            (else (< (cdr a) (cdr b)))))
 
     (define (analyse-span-event active ev)
-      (let* ((name (ly:event-property ev 'class))
-	     (key (cond ((equal? name 'slur-event) 'slur)
-			((equal? name 'phrasing-slur-event) 'tie)
-			((equal? name 'beam-event) 'beam)
-			((equal? name 'crescendo-event) 'cresc)
-			((equal? name 'decrescendo-event) 'decr)
-			(else #f)))
-	     (sp (ly:event-property ev 'span-direction)))
-	(if (and (symbol? key) (ly:dir? sp))
-	    (if (= sp STOP)
-		(assoc-remove! active key)
-		(acons key
-		       (split-index (vector-ref voice-state-vec index))
-		       active))
-	    active)))
+      (let* ((name (car (ly:event-property ev 'class)))
+             (key (cond ((equal? name 'slur-event) 'slur)
+                        ((equal? name 'phrasing-slur-event) 'tie)
+                        ((equal? name 'beam-event) 'beam)
+                        ((equal? name 'crescendo-event) 'cresc)
+                        ((equal? name 'decrescendo-event) 'decr)
+                        (else #f)))
+             (sp (ly:event-property ev 'span-direction)))
+        (if (and (symbol? key) (ly:dir? sp))
+            (if (= sp STOP)
+                (assoc-remove! active key)
+                (acons key
+                       (split-index (vector-ref voice-state-vec index))
+                       active))
+            active)))
 
     (define (analyse-events active evs)
       "Run all analyzers on ACTIVE and EVS"
       (define (run-analyzer analyzer active evs)
-	(if (pair? evs)
-	    (run-analyzer analyzer (analyzer active (car evs)) (cdr evs))
-	    active))
+        (if (pair? evs)
+            (run-analyzer analyzer (analyzer active (car evs)) (cdr evs))
+            active))
       (define (run-analyzers analyzers active evs)
-	(if (pair? analyzers)
-	    (run-analyzers (cdr analyzers)
-			   (run-analyzer (car analyzers) active evs)
-			   evs)
-	    active))
+        (if (pair? analyzers)
+            (run-analyzers (cdr analyzers)
+                           (run-analyzer (car analyzers) active evs)
+                           evs)
+            active))
       (sort ;; todo: use fold or somesuch.
        (run-analyzers (list analyse-absdyn-end analyse-span-event
-			    ;; note: tie-start/span comes after tie-end/absdyn.
-			    analyse-tie-end analyse-tie-start)
-		      active evs)
+                            ;; note: tie-start/span comes after tie-end/absdyn.
+                            analyse-tie-end analyse-tie-start)
+                      active evs)
        active<?))
 
     ;; must copy, since we use assoc-remove!
     (if (< index (vector-length voice-state-vec))
-	(begin
-	  (set! active (analyse-events active (events (vector-ref voice-state-vec index))))
-	  (set! (span-state (vector-ref voice-state-vec index))
-		(list-copy active))
-	  (helper (1+ index) active))))
+        (begin
+          (set! active (analyse-events active (events (vector-ref voice-state-vec index))))
+          (set! (span-state (vector-ref voice-state-vec index))
+                (list-copy active))
+          (helper (1+ index) active))))
 
   (helper 0 '()))
 
+(define recording-group-functions
+  ;;Selected parts from @var{toplevel-music-functions} not requiring @code{parser}.
+  (list
+   (lambda (music) (expand-repeat-chords! '(rhythmic-event) music))
+   expand-repeat-notes!))
+
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (define-public (recording-group-emulate music odef)
   "Interpret @var{music} according to @var{odef}, but store all events
 in a chronological list, similar to the @code{Recording_group_engraver} in
 LilyPond version 2.8 and earlier."
   (let*
-     ((context-list '())
-      (now-mom (ly:make-moment 0 0))
-      (global (ly:make-global-context odef))
-      (mom-listener (ly:make-listener
-             (lambda (tev) (set! now-mom (ly:event-property tev 'moment)))))
-      (new-context-listener
-       (ly:make-listener
-        (lambda (sev)
-          (let*
-             ((child (ly:event-property sev 'context))
-              (this-moment-list (cons (ly:context-id child) '()))
-              (dummy (set! context-list (cons this-moment-list context-list)))
-              (acc '())
-              (accumulate-event-listener
-                  (ly:make-listener (lambda (ev)
-                                       (set! acc (cons (cons ev #t) acc)))))
-              (save-acc-listener
-                  (ly:make-listener (lambda (tev)
-                      (if (pair? acc)
-                        (let ((this-moment
-                              (cons (cons now-mom
-                                (ly:context-property child 'instrumentTransposition))
-                                ;; The accumulate-event-listener above creates
-                                ;; the list of events in reverse order, so we
-                                ;; have to revert it to the original order again
-                                (reverse acc))))
-                          (set-cdr! this-moment-list
-                                (cons this-moment (cdr this-moment-list)))
-                          (set! acc '())))))))
-            (ly:add-listener accumulate-event-listener
-                (ly:context-event-source child) 'StreamEvent)
-            (ly:add-listener save-acc-listener
-                (ly:context-event-source global) 'OneTimeStep))))))
+      ((context-list '())
+       (now-mom (ly:make-moment 0 0))
+       (global (ly:make-global-context odef))
+       (mom-listener (ly:make-listener
+                      (lambda (tev) (set! now-mom (ly:event-property tev 'moment)))))
+       (new-context-listener
+        (ly:make-listener
+         (lambda (sev)
+           (let*
+               ((child (ly:event-property sev 'context))
+                (this-moment-list (cons (ly:context-id child) '()))
+                (dummy (set! context-list (cons this-moment-list context-list)))
+                (acc '())
+                (accumulate-event-listener
+                 (ly:make-listener (lambda (ev)
+                                     (set! acc (cons (cons ev #t) acc)))))
+                (save-acc-listener
+                 (ly:make-listener (lambda (tev)
+                                     (if (pair? acc)
+                                         (let ((this-moment
+                                                (cons (cons now-mom
+                                                            (ly:context-property child 'instrumentTransposition))
+                                                      ;; The accumulate-event-listener above creates
+                                                      ;; the list of events in reverse order, so we
+                                                      ;; have to revert it to the original order again
+                                                      (reverse acc))))
+                                           (set-cdr! this-moment-list
+                                                     (cons this-moment (cdr this-moment-list)))
+                                           (set! acc '())))))))
+             (ly:add-listener accumulate-event-listener
+                              (ly:context-event-source child) 'StreamEvent)
+             (ly:add-listener save-acc-listener
+                              (ly:context-event-source global) 'OneTimeStep))))))
     (ly:add-listener new-context-listener
-        (ly:context-events-below global) 'AnnounceNewContext)
+                     (ly:context-events-below global) 'AnnounceNewContext)
     (ly:add-listener mom-listener (ly:context-event-source global) 'Prepare)
-    (ly:interpret-music-expression (make-non-relative-music music) global)
+    (ly:interpret-music-expression
+     (make-non-relative-music
+      (fold (lambda (x m) (x m)) music recording-group-functions))
+     global)
     context-list))
 
-(define-public (make-part-combine-music parser music-list)
+(define-public (make-part-combine-music parser music-list direction chord-range)
   (let* ((m (make-music 'PartCombineMusic))
-	 (m1 (make-non-relative-music (context-spec-music (first music-list) 'Voice "one")))
-	 (m2  (make-non-relative-music  (context-spec-music (second music-list) 'Voice "two")))
-	 (listener (ly:parser-lookup parser 'partCombineListener))
-	 (evs2 (recording-group-emulate m2 listener))
-	 (evs1 (recording-group-emulate m1 listener)))
+         (m1 (make-non-relative-music (context-spec-music (first music-list) 'Voice "one")))
+         (m2  (make-non-relative-music  (context-spec-music (second music-list) 'Voice "two")))
+         (listener (ly:parser-lookup parser 'partCombineListener))
+         (evs2 (recording-group-emulate m2 listener))
+         (evs1 (recording-group-emulate m1 listener)))
 
     (set! (ly:music-property m 'elements) (list m1 m2))
+    (set! (ly:music-property m 'direction) direction)
     (set! (ly:music-property m 'split-list)
-	  (if (and (assoc "one" evs1) (assoc "two" evs2))
-	      (determine-split-list (reverse! (assoc-get "one" evs1) '())
-				    (reverse! (assoc-get "two" evs2) '()))
-	      '()))
+          (if (and (assoc "one" evs1) (assoc "two" evs2))
+              (determine-split-list (reverse! (assoc-get "one" evs1) '())
+                                    (reverse! (assoc-get "two" evs2) '())
+                                    chord-range)
+              '()))
     m))
 
-(define-public (determine-split-list evl1 evl2)
-  "@var{evl1} and @var{evl2} should be ascending."
+(define-public (determine-split-list evl1 evl2 chord-range)
+  "@var{evl1} and @var{evl2} should be ascending. @var{chord-range} is a pair of numbers (min . max) defining the distance in steps between notes that may be combined into a chord or unison."
   (let* ((pc-debug #f)
-	 (chord-threshold 8)
-	 (voice-state-vec1 (make-voice-states evl1))
-	 (voice-state-vec2 (make-voice-states evl2))
-	 (result (make-split-state voice-state-vec1 voice-state-vec2)))
+         (voice-state-vec1 (make-voice-states evl1))
+         (voice-state-vec2 (make-voice-states evl2))
+         (result (make-split-state voice-state-vec1 voice-state-vec2))
+         (chord-min-diff (car chord-range))
+         (chord-max-diff (cdr chord-range)))
 
     ;; Go through all moments recursively and check if the events of that
     ;; moment contain a part-combine-force-event override. If so, store its
@@ -274,274 +293,320 @@ LilyPond version 2.8 and earlier."
     (define (analyse-forced-combine result-idx prev-res)
 
       (define (get-forced-event x)
-	(if (ly:in-event-class? x 'part-combine-force-event)
-	    (cons (ly:event-property x 'forced-type) (ly:event-property x 'once))
-	    #f))
+        (and (ly:in-event-class? x 'part-combine-force-event)
+             (cons (ly:event-property x 'forced-type)
+                   (ly:event-property x 'once))))
       (define (part-combine-events vs)
-	(if (not vs)
-	    '()
-	    (filter-map get-forced-event (events vs))))
+        (if (not vs)
+            '()
+            (filter-map get-forced-event (events vs))))
       ;; end part-combine-events
 
       ;; forced-result: Take the previous config and analyse whether
       ;; any change happened.... Return new once and permanent config
       (define (forced-result evt state)
-	;; sanity check, evt should always be (new-state . once)
-	(if (not (and (pair? evt) (pair? state)))
-	    state
-	    (if (cdr evt)
-		;; Once-event, leave permanent state unchanged
-		(cons (car evt) (cdr state))
-		;; permanent change, leave once state unchanged
-		(cons (car state) (car evt)))))
+        ;; sanity check, evt should always be (new-state . once)
+        (if (not (and (pair? evt) (pair? state)))
+            state
+            (if (cdr evt)
+                ;; Once-event, leave permanent state unchanged
+                (cons (car evt) (cdr state))
+                ;; permanent change, leave once state unchanged
+                (cons (car state) (car evt)))))
       ;; end forced-combine-result
 
       ;; body of analyse-forced-combine:
       (if (< result-idx (vector-length result))
-	  (let* ((now-state (vector-ref result result-idx)) ; current result
-		 ;; Extract all part-combine force events
-		 (ev1 (part-combine-events (car (voice-states now-state))))
-		 (ev2 (part-combine-events (cdr (voice-states now-state))))
-		 (evts (append ev1 ev2))
-		 ;; result is (once-state permament-state):
-		 (state (fold forced-result (cons 'automatic prev-res) evts))
-		 ;; Now let once override permanent changes:
-		 (force-state (if (equal? (car state) 'automatic)
-				  (cdr state)
-				  (car state))))
-	    (set! (forced-configuration (vector-ref result result-idx))
-		  force-state)
-	    ;; For the next moment, ignore the once override (car stat)
-	    ;; and pass on the permanent override, stored as (cdr state)
-	    (analyse-forced-combine (1+ result-idx) (cdr state)))))
+          (let* ((now-state (vector-ref result result-idx)) ; current result
+                 ;; Extract all part-combine force events
+                 (evts (if (synced? now-state)
+                           (append
+                            (part-combine-events (car (voice-states now-state)))
+                            (part-combine-events (cdr (voice-states now-state))))
+                           '()))
+                 ;; result is (once-state permament-state):
+                 (state (fold forced-result (cons 'automatic prev-res) evts))
+                 ;; Now let once override permanent changes:
+                 (force-state (if (equal? (car state) 'automatic)
+                                  (cdr state)
+                                  (car state))))
+            (set! (forced-configuration (vector-ref result result-idx))
+                  force-state)
+            ;; For the next moment, ignore the once override (car stat)
+            ;; and pass on the permanent override, stored as (cdr state)
+            (analyse-forced-combine (1+ result-idx) (cdr state)))))
     ;; end analyse-forced-combine
 
 
     (define (analyse-time-step result-idx)
       (define (put x . index)
-	"Put the result to X, starting from INDEX backwards.
+        "Put the result to X, starting from INDEX backwards.
 
 Only set if not set previously.
 "
-	(let ((i (if (pair? index) (car index) result-idx)))
-	  (if (and (<= 0 i)
-		   (not (symbol? (configuration (vector-ref result i)))))
-	      (begin
-		(set! (configuration (vector-ref result i)) x)
-		(put x (1- i))))))
+        (let ((i (if (pair? index) (car index) result-idx)))
+          (if (and (<= 0 i)
+                   (not (symbol? (configuration (vector-ref result i)))))
+              (begin
+                (set! (configuration (vector-ref result i)) x)
+                (put x (1- i))))))
 
       (define (copy-state-from state-vec vs)
-	(define (copy-one-state key-idx)
-	  (let* ((idx (cdr key-idx))
-		 (prev-ss (vector-ref result idx))
-		 (prev (configuration prev-ss)))
-	    (if (symbol? prev)
-		(put prev))))
-	(map copy-one-state (span-state vs)))
+        (define (copy-one-state key-idx)
+          (let* ((idx (cdr key-idx))
+                 (prev-ss (vector-ref result idx))
+                 (prev (configuration prev-ss)))
+            (if (symbol? prev)
+                (put prev))))
+        (for-each copy-one-state (span-state vs)))
 
       (define (analyse-notes now-state)
-	(let* ((vs1 (car (voice-states now-state)))
-	       (vs2 (cdr (voice-states now-state)))
-	       (notes1 (note-events vs1))
-	       (durs1 (sort (map (lambda (x) (ly:event-property x 'duration))
-				 notes1)
-			    ly:duration<?))
-	       (pitches1 (sort (map (lambda (x) (ly:event-property x 'pitch))
-				    notes1)
-			       ly:pitch<?))
-	       (notes2 (note-events vs2))
-	       (durs2 (sort (map (lambda (x) (ly:event-property x 'duration))
-				 notes2)
-			    ly:duration<?))
-	       (pitches2 (sort (map (lambda (x) (ly:event-property x 'pitch))
-				    notes2)
-			       ly:pitch<?)))
-	  (cond ((> (length notes1) 1) (put 'apart))
-		((> (length notes2) 1) (put 'apart))
-		((= 1 (+ (length notes2) (length notes1))) (put 'apart))
-		((and (= (length durs1) 1)
-		      (= (length durs2) 1)
-		      (not (equal? (car durs1) (car durs2))))
-		 (put 'apart))
-		(else
-		 (if (and (= (length pitches1) (length pitches2)))
-		     (if (and (pair? pitches1)
-			      (pair? pitches2)
-			      (or
-			       (< chord-threshold (ly:pitch-steps
-						   (ly:pitch-diff (car pitches1)
-								  (car pitches2))))
-
-			       ;; voice crossings:
-			       (> 0 (ly:pitch-steps (ly:pitch-diff (car pitches1)
-								   (car pitches2))))
-			       ))
-			 (put 'apart)
-			 ;; copy previous split state from spanner state
-			 (begin
-			   (if (previous-voice-state vs1)
-			       (copy-state-from voice-state-vec1
-						(previous-voice-state vs1)))
-			   (if (previous-voice-state vs2)
-			       (copy-state-from voice-state-vec2
-						(previous-voice-state vs2)))
-			   (if (and (null? (span-state vs1)) (null? (span-state vs2)))
-			       (put 'chords)))))))))
+        (let* ((vs1 (car (voice-states now-state)))
+               (vs2 (cdr (voice-states now-state)))
+               (notes1 (note-events vs1))
+               (durs1 (sort (map (lambda (x) (ly:event-property x 'duration))
+                                 notes1)
+                            ly:duration<?))
+               (pitches1 (sort (map (lambda (x) (ly:event-property x 'pitch))
+                                    notes1)
+                               ly:pitch<?))
+               (notes2 (note-events vs2))
+               (durs2 (sort (map (lambda (x) (ly:event-property x 'duration))
+                                 notes2)
+                            ly:duration<?))
+               (pitches2 (sort (map (lambda (x) (ly:event-property x 'pitch))
+                                    notes2)
+                               ly:pitch<?)))
+          (cond ((> (length notes1) 1) (put 'apart))
+                ((> (length notes2) 1) (put 'apart))
+                ((= 1 (+ (length notes2) (length notes1))) (put 'apart))
+                ((and (= (length durs1) 1)
+                      (= (length durs2) 1)
+                      (not (equal? (car durs1) (car durs2))))
+                 (put 'apart))
+                (else
+                 (if (and (= (length pitches1) (length pitches2)))
+                     (if (and (pair? pitches1)
+                              (pair? pitches2)
+                              ; Is the interval outside of chord-range?
+                              (let ((diff (ly:pitch-steps
+                                           (ly:pitch-diff (car pitches1)
+                                                          (car pitches2)))))
+                                (or (< diff chord-min-diff)
+                                    (> diff chord-max-diff)
+                                    )))
+                         (put 'apart)
+                         ;; copy previous split state from spanner state
+                         (begin
+                           (if (previous-voice-state vs1)
+                               (copy-state-from voice-state-vec1
+                                                (previous-voice-state vs1)))
+                           (if (previous-voice-state vs2)
+                               (copy-state-from voice-state-vec2
+                                                (previous-voice-state vs2)))
+                           (if (and (null? (span-state vs1)) (null? (span-state vs2)))
+                               (put 'chords)))))))))
 
       (if (< result-idx (vector-length result))
-	  (let* ((now-state (vector-ref result result-idx))
-		 (vs1 (car (voice-states now-state)))
-		 (vs2 (cdr (voice-states now-state))))
-
-	    (cond ((not vs1) (put 'apart))
-		  ((not vs2) (put 'apart))
-		  (else
-		   (let ((active1 (previous-span-state vs1))
-			 (active2 (previous-span-state vs2))
-			 (new-active1 (span-state vs1))
-			 (new-active2 (span-state vs2)))
-		     (if #f ; debug
-			 (display (list (when now-state) result-idx
-					active1 "->" new-active1
-					active2 "->" new-active2
-					"\n")))
-		     (if (and (synced? now-state)
-			      (equal? active1 active2)
-			      (equal? new-active1 new-active2))
-			 (analyse-notes now-state)
-
-			 ;; active states different:
-			 (put 'apart)))
-
-		   ;; go to the next one, if it exists.
-		   (analyse-time-step (1+ result-idx)))))))
+          (let* ((now-state (vector-ref result result-idx))
+                 (vs1 (car (voice-states now-state)))
+                 (vs2 (cdr (voice-states now-state))))
+
+            (cond ((not vs1) (put 'apart))
+                  ((not vs2) (put 'apart))
+                  (else
+                   (let ((active1 (previous-span-state vs1))
+                         (active2 (previous-span-state vs2))
+                         (new-active1 (span-state vs1))
+                         (new-active2 (span-state vs2)))
+                     (if #f ; debug
+                         (display (list (moment now-state) result-idx
+                                        active1 "->" new-active1
+                                        active2 "->" new-active2
+                                        "\n")))
+                     (if (and (synced? now-state)
+                              (equal? active1 active2)
+                              (equal? new-active1 new-active2))
+                         (analyse-notes now-state)
+
+                         ;; active states different:
+                         (put 'apart)))
+
+                   ;; go to the next one, if it exists.
+                   (analyse-time-step (1+ result-idx)))))))
 
     (define (analyse-a2 result-idx)
       (if (< result-idx (vector-length result))
-	  (let* ((now-state (vector-ref result result-idx))
-		 (vs1 (car (voice-states now-state)))
-		 (vs2 (cdr (voice-states now-state))))
-	    (if (and (equal? (configuration now-state) 'chords)
-		     vs1 vs2)
-		(let ((notes1 (note-events vs1))
-		      (notes2 (note-events vs2)))
-		  (cond ((and (= 1 (length notes1))
-			      (= 1 (length notes2))
-			      (equal? (ly:event-property (car notes1) 'pitch)
-				      (ly:event-property (car notes2) 'pitch)))
-			 (set! (configuration now-state) 'unisono))
-			((and (= 0 (length notes1))
-			      (= 0 (length notes2)))
-			 (set! (configuration now-state) 'unisilence)))))
-	    (analyse-a2 (1+ result-idx)))))
+          (let* ((now-state (vector-ref result result-idx))
+                 (vs1 (car (voice-states now-state)))
+                 (vs2 (cdr (voice-states now-state))))
+
+            (define (analyse-silence)
+              (let ((rests1 (if vs1 (rest-and-skip-events vs1) '()))
+                    (rests2 (if vs2 (rest-and-skip-events vs2) '())))
+                (cond
+                 
+                 ;; multi-measure rests (probably), which the
+                 ;; part-combine iterator handles well
+                 ((and (synced? now-state)
+                       (= 0 (length rests1))
+                       (= 0 (length rests2)))
+                  (set! (configuration now-state) 'unisilence))
+                 
+                 ;; equal rests or equal skips, but not one of each
+                 ((and (synced? now-state)
+                       (= 1 (length rests1))
+                       (= 1 (length rests2))
+                       (equal? (ly:event-property (car rests1) 'class)
+                               (ly:event-property (car rests2) 'class))
+                       (equal? (ly:event-property (car rests1) 'duration)
+                               (ly:event-property (car rests2) 'duration)))
+                  (set! (configuration now-state) 'unisilence))
+                 
+                 ;; rests of different durations or mixed with
+                 ;; skips or multi-measure rests
+                 ((synced? now-state)
+                  ;; TODO When one part has a rest and the other has a
+                  ;; multi-measure rest, tell the part-combine
+                  ;; iterator to route the part with the rest to the
+                  ;; shared voice.  Until there is a way to do this,
+                  ;; we print them both; it does not look very good,
+                  ;; but failing to print the rest is misleading.
+                  ;;
+                  ;; Maybe do something similar for skips; route
+                  ;; the rest to the shared voice and the skip to
+                  ;; the voice for its part.
+                  (set! (configuration now-state) 'apart-silence))
+                 
+                 ;; TODO At a multi-measure rest, return to unisilence
+                 ;; even after having been apart.  The results are not
+                 ;; good now because of the deficiency mentioned
+                 ;; above.
+                 )))
+
+            (if (or vs1 vs2)
+                (let ((notes1 (if vs1 (note-events vs1) '()))
+                      (notes2 (if vs2 (note-events vs2) '())))
+                  ; Todo: What about a2 chords, e.g. string multi-stops?
+                  ; Sort and compare notes1 and notes2?
+                  (cond ((and (equal? (configuration now-state) 'chords)
+                              (= 1 (length notes1))
+                              (= 1 (length notes2))
+                              (equal? (ly:event-property (car notes1) 'pitch)
+                                      (ly:event-property (car notes2) 'pitch)))
+                         (set! (configuration now-state) 'unisono))
+                        ((and (= 0 (length notes1))
+                              (= 0 (length notes2)))
+                         (analyse-silence)))))
+            (analyse-a2 (1+ result-idx)))))
 
     (define (analyse-solo12 result-idx)
 
       (define (previous-config vs)
-	(let* ((pvs (previous-voice-state vs))
-	       (spi (if pvs (split-index pvs) #f))
-	       (prev-split (if spi (vector-ref result spi) #f)))
-	  (if prev-split
-	      (configuration prev-split)
-	      'apart)))
+        (let* ((pvs (previous-voice-state vs))
+               (spi (if pvs (split-index pvs) #f))
+               (prev-split (if spi (vector-ref result spi) #f)))
+          (if prev-split
+              (configuration prev-split)
+              'apart)))
 
       (define (put-range x a b)
-	;; (display (list "put range "	x a b "\n"))
-	(do ((i a (1+ i)))
-	    ((> i b) b)
-	  (set! (configuration (vector-ref result i)) x)))
+        ;; (display (list "put range "  x a b "\n"))
+        (do ((i a (1+ i)))
+            ((> i b) b)
+          (set! (configuration (vector-ref result i)) x)))
 
       (define (put x)
-	;; (display (list "putting "  x "\n"))
-	(set! (configuration (vector-ref result result-idx)) x))
+        ;; (display (list "putting "  x "\n"))
+        (set! (configuration (vector-ref result result-idx)) x))
 
       (define (current-voice-state now-state voice-num)
-	(define vs ((if (= 1 voice-num) car cdr)
-		    (voice-states now-state)))
-	(if (or (not vs) (equal? (when now-state) (when vs)))
-	    vs
-	    (previous-voice-state vs)))
+        (define vs ((if (= 1 voice-num) car cdr)
+                    (voice-states now-state)))
+        (if (or (not vs) (equal? (moment now-state) (moment vs)))
+            vs
+            (previous-voice-state vs)))
 
       (define (try-solo type start-idx current-idx)
-	"Find a maximum stretch that can be marked as solo.  Only set
+        "Find a maximum stretch that can be marked as solo.  Only set
 the mark when there are no spanners active.
 
       return next idx to analyse.
 "
-	(if (< current-idx (vector-length result))
-	    (let* ((now-state (vector-ref result current-idx))
-		   (solo-state (current-voice-state now-state (if (equal? type 'solo1) 1 2)))
-		   (silent-state (current-voice-state now-state (if (equal? type 'solo1) 2 1)))
-		   (silent-notes (if silent-state (note-events silent-state) '()))
-		   (solo-notes (if solo-state (note-events solo-state) '())))
-	      ;; (display (list "trying " type " at "  (when now-state) solo-state silent-state	 "\n"))
-	      (cond ((not (equal? (configuration now-state) 'apart))
-		     current-idx)
-		    ((> (length silent-notes) 0) start-idx)
-		    ((not solo-state)
-		     (put-range type start-idx current-idx)
-		     current-idx)
-		    ((and
-		      (null? (span-state solo-state)))
-
-		     ;;
-		     ;; This includes rests. This isn't a problem: long rests
-		     ;; will be shared with the silent voice, and be marked
-		     ;; as unisilence. Therefore, long rests won't
-		     ;;	 accidentally be part of a solo.
-		     ;;
-		     (put-range type start-idx current-idx)
-		     (try-solo type (1+ current-idx) (1+  current-idx)))
-		    (else
-		     (try-solo type start-idx (1+ current-idx)))))
-	    ;; try-solo
-	    start-idx))
+        (if (< current-idx (vector-length result))
+            (let* ((now-state (vector-ref result current-idx))
+                   (solo-state (current-voice-state now-state (if (equal? type 'solo1) 1 2)))
+                   (silent-state (current-voice-state now-state (if (equal? type 'solo1) 2 1)))
+                   (silent-notes (if silent-state (note-events silent-state) '()))
+                   (solo-notes (if solo-state (note-events solo-state) '())))
+              ;; (display (list "trying " type " at "  (moment now-state) solo-state silent-state        "\n"))
+              (cond ((not (equal? (configuration now-state) 'apart))
+                     current-idx)
+                    ((> (length silent-notes) 0) start-idx)
+                    ((not solo-state)
+                     (put-range type start-idx current-idx)
+                     current-idx)
+                    ((and
+                      (null? (span-state solo-state)))
+
+                     ;;
+                     ;; This includes rests. This isn't a problem: long rests
+                     ;; will be shared with the silent voice, and be marked
+                     ;; as unisilence. Therefore, long rests won't
+                     ;;  accidentally be part of a solo.
+                     ;;
+                     (put-range type start-idx current-idx)
+                     (try-solo type (1+ current-idx) (1+  current-idx)))
+                    (else
+                     (try-solo type start-idx (1+ current-idx)))))
+            ;; try-solo
+            start-idx))
 
       (define (analyse-moment result-idx)
-	"Analyse 'apart starting at RESULT-IDX.  Return next index."
-	(let* ((now-state (vector-ref result result-idx))
-	       (vs1 (current-voice-state now-state 1))
-	       (vs2 (current-voice-state now-state 2))
-	       ;; (vs1 (car (voice-states now-state)))
-	       ;; (vs2 (cdr (voice-states now-state)))
-	       (notes1 (if vs1 (note-events vs1) '()))
-	       (notes2 (if vs2 (note-events vs2) '()))
-	       (n1 (length notes1))
-	       (n2 (length notes2)))
-	  ;; (display (list "analyzing step " result-idx "  moment " (when now-state) vs1 vs2  "\n"))
-	  (max
-	   ;; we should always increase.
-	   (cond ((and (= n1 0) (= n2 0))
-		  (put 'apart-silence)
-		  (1+ result-idx))
-		 ((and (= n2 0)
-		       (equal? (when vs1) (when now-state))
-		       (null? (previous-span-state vs1)))
-		  (try-solo 'solo1 result-idx result-idx))
-		 ((and (= n1 0)
-		       (equal? (when vs2) (when now-state))
-		       (null? (previous-span-state vs2)))
-		  (try-solo 'solo2 result-idx result-idx))
-
-		 (else (1+ result-idx)))
-	   ;; analyse-moment
-	   (1+ result-idx))))
+        "Analyse 'apart starting at RESULT-IDX.  Return next index."
+        (let* ((now-state (vector-ref result result-idx))
+               (vs1 (current-voice-state now-state 1))
+               (vs2 (current-voice-state now-state 2))
+               ;; (vs1 (car (voice-states now-state)))
+               ;; (vs2 (cdr (voice-states now-state)))
+               (notes1 (if vs1 (note-events vs1) '()))
+               (notes2 (if vs2 (note-events vs2) '()))
+               (n1 (length notes1))
+               (n2 (length notes2)))
+          ;; (display (list "analyzing step " result-idx "  moment " (moment now-state) vs1 vs2  "\n"))
+          (max
+           ;; we should always increase.
+           (cond ((and (= n1 0) (= n2 0))
+                  (put 'apart-silence)
+                  (1+ result-idx))
+                 ((and (= n2 0)
+                       (equal? (moment vs1) (moment now-state))
+                       (null? (previous-span-state vs1)))
+                  (try-solo 'solo1 result-idx result-idx))
+                 ((and (= n1 0)
+                       (equal? (moment vs2) (moment now-state))
+                       (null? (previous-span-state vs2)))
+                  (try-solo 'solo2 result-idx result-idx))
+
+                 (else (1+ result-idx)))
+           ;; analyse-moment
+           (1+ result-idx))))
 
       (if (< result-idx (vector-length result))
-	  (if (equal? (configuration (vector-ref result result-idx)) 'apart)
-	      (analyse-solo12 (analyse-moment result-idx))
-	      (analyse-solo12 (1+ result-idx))))) ; analyse-solo12
+          (if (equal? (configuration (vector-ref result result-idx)) 'apart)
+              (analyse-solo12 (analyse-moment result-idx))
+              (analyse-solo12 (1+ result-idx))))) ; analyse-solo12
 
     (analyse-spanner-states voice-state-vec1)
     (analyse-spanner-states voice-state-vec2)
     (if #f
-	(begin
-	  (display voice-state-vec1)
-	  (display "***\n")
-	  (display voice-state-vec2)
-	  (display "***\n")
-	  (display result)
-	  (display "***\n")))
+        (begin
+          (display voice-state-vec1)
+          (display "***\n")
+          (display voice-state-vec2)
+          (display "***\n")
+          (display result)
+          (display "***\n")))
 
     ;; Extract all forced combine strategies, i.e. events inserted by
     ;; \partcombine(Apart|Automatic|SoloI|SoloII|Chords)[Once]
@@ -559,11 +624,11 @@ the mark when there are no spanners active.
     (analyse-solo12 0)
     ;; (display result)
     (set! result (map
-		  ;; forced-configuration overrides, if it is set
-		  (lambda (x) (cons (when x) (or (forced-configuration x) (configuration x))))
-		  (vector->list result)))
+                  ;; forced-configuration overrides, if it is set
+                  (lambda (x) (cons (moment x) (or (forced-configuration x) (configuration x))))
+                  (vector->list result)))
     (if #f ;; pc-debug
-	 (display result))
+        (display result))
     result))
 
 
@@ -594,4 +659,4 @@ the mark when there are no spanners active.
 
     (if (not (null? quote-contents))
         (hash-set! tab name (list->vector (reverse! quote-contents '())))
-        (ly:music-message mus (ly:format (_ "quoted music `~a' is empty") name)))))
+        (ly:music-warning mus (ly:format (_ "quoted music `~a' is empty") name)))))