Use make-engraver when feasible

7 files changed, 167 insertions, 205 deletions

diff --git a/Documentation/snippets/new/centering-markup-on-note-heads-automatically.ly b/Documentation/snippets/new/centering-markup-on-note-heads-automatically.ly
index 47169a559b..2d1ec280ef 100644
--- a/Documentation/snippets/new/centering-markup-on-note-heads-automatically.ly
+++ b/Documentation/snippets/new/centering-markup-on-note-heads-automatically.ly
@@ -1,4 +1,4 @@
-\version "2.14.0"
+\version "2.15.31"
 
 \header {
   lsrtags = "text, tweaks-and-overrides, contexts-and-engravers"
@@ -17,29 +17,23 @@ been shifted via @code{force-hshift}.
 #(define (Text_align_engraver ctx)
   (let ((scripts '())
         (note-column #f))
-
-    `((acknowledgers
-       (note-column-interface
-        . ,(lambda (trans grob source)
-             ;; cache NoteColumn in this Voice context
-             (set! note-column grob)))
-
-       (text-script-interface
-        . ,(lambda (trans grob source)
-             ;; whenever a TextScript is acknowledged,
-             ;; add it to `scripts' list
-             (set! scripts (cons grob scripts)))))
-
-      (stop-translation-timestep
-       . ,(lambda (trans)
-            ;; if any TextScript grobs exist,
-            ;; set NoteColumn as X-parent
-            (and (pair? scripts)
-                 (for-each (lambda (script)
-                             (set! (ly:grob-parent script X) note-column))
-                           scripts))
-            ;; clear scripts ready for next timestep
-            (set! scripts '()))))))
+    (make-engraver
+     (acknowledgers
+      ((note-column-interface trans grob source)
+       ;; cache NoteColumn in this Voice context
+       (set! note-column grob))
+      ((text-script-interface trans grob source)
+       ;; whenever a TextScript is acknowledged,
+       ;; add it to `scripts' list
+       (set! scripts (cons grob scripts))))
+     ((stop-translation-timestep trans)
+      ;; if any TextScript grobs exist,
+      ;; set NoteColumn as X-parent
+      (for-each (lambda (script)
+		  (set! (ly:grob-parent script X) note-column))
+		scripts)
+      ;; clear scripts ready for next timestep
+      (set! scripts '())))))
 
 \layout {
   \context {
diff --git a/Documentation/snippets/new/defining-an-engraver-in-scheme-ambitus-engraver.ly b/Documentation/snippets/new/defining-an-engraver-in-scheme-ambitus-engraver.ly
index 379dc69147..8958cd9e12 100644
--- a/Documentation/snippets/new/defining-an-engraver-in-scheme-ambitus-engraver.ly
+++ b/Documentation/snippets/new/defining-an-engraver-in-scheme-ambitus-engraver.ly
@@ -1,4 +1,4 @@
-\version "2.14.0"
+\version "2.15.31"
 
 \header {
 
@@ -21,10 +21,6 @@
 %%% Grob utilities
 %%%
 %%% These are literal rewrites of some C++ methods used by the ambitus engraver.
-#(define (ly:event::in-event-class event class-name)
-   "Check if @var{event} the given class.
-Rewrite of @code{Stream_event::internal_in_event_class} from @file{lily/stream-event.cc}."
-   (memq class-name (ly:make-event-class (ly:event-property event 'class))))
 
 #(define (ly:separation-item::add-conditional-item grob grob-item)
    "Add @var{grob-item} to the array of conditional elements of @var{grob}.
@@ -188,7 +184,7 @@ position of middle C and key signature from @var{translator}'s context."
    ;; Get the event that caused the note-grob creation
    ;; and check that it is a note-event.
    (let ((note-event (ly:grob-property note-grob 'cause)))
-     (if (ly:event::in-event-class note-event 'note-event)
+     (if (ly:in-event-class? note-event 'note-event)
          ;; get the pitch from the note event
          (let ((pitch (ly:event-property note-event 'pitch)))
            ;; if this pitch is lower than the current ambitus lower
@@ -292,23 +288,24 @@ position of middle C and key signature from @var{translator}'s context."
    (lambda (context)
      (let ((ambitus #f))
        ;; when music is processed: make the ambitus object, if not already built
-       `((process-music . ,(lambda (translator)
-                             (if (not ambitus)
-                                 (set! ambitus (make-ambitus translator)))))
-         ;; set the ambitus clef and key signature state
-         (stop-translation-timestep . ,(lambda (translator)
-                                         (if ambitus
-                                             (initialize-ambitus-state ambitus translator))))
-         ;; when a note-head grob is built, update the ambitus notes
-         (acknowledgers
-          (note-head-interface . ,(lambda (engraver grob source-engraver)
-                                    (if ambitus
-                                        (update-ambitus-notes ambitus grob)))))
-         ;; finally, typeset the ambitus according to its upper and lower notes
-         ;; (if any).
-         (finalize . ,(lambda (translator)
-                        (if ambitus
-                            (typeset-ambitus ambitus translator))))))))
+       (make-engraver
+	((process-music translator)
+	 (if (not ambitus)
+	     (set! ambitus (make-ambitus translator))))
+	;; set the ambitus clef and key signature state
+	((stop-translation-timestep translator)
+	 (if ambitus
+	     (initialize-ambitus-state ambitus translator)))
+	;; when a note-head grob is built, update the ambitus notes
+	(acknowledgers
+          ((note-head-interface engraver grob source-engraver)
+	   (if ambitus
+	       (update-ambitus-notes ambitus grob))))
+	;; finally, typeset the ambitus according to its upper and lower notes
+	;; (if any).
+	((finalize translator)
+	 (if ambitus
+	     (typeset-ambitus ambitus translator)))))))
 
 %%%
 %%% Example
diff --git a/Documentation/snippets/new/numbers-as-easy-note-heads.ly b/Documentation/snippets/new/numbers-as-easy-note-heads.ly
index 03e0578af2..2b86eb9f1a 100644
--- a/Documentation/snippets/new/numbers-as-easy-note-heads.ly
+++ b/Documentation/snippets/new/numbers-as-easy-note-heads.ly
@@ -1,4 +1,4 @@
-\version "2.14.0"
+\version "2.15.31"
 
 \header {
   lsrtags = "pitches"
@@ -15,21 +15,19 @@ object it sees.
 }
 
 #(define Ez_numbers_engraver
-   (list
-    (cons 'acknowledgers
-          (list
-           (cons 'note-head-interface
-                 (lambda (engraver grob source-engraver)
-                   (let* ((context (ly:translator-context engraver))
-                          (tonic-pitch (ly:context-property context 'tonic))
-                          (tonic-name (ly:pitch-notename tonic-pitch))
-                          (grob-pitch
-                           (ly:event-property (event-cause grob) 'pitch))
-                          (grob-name (ly:pitch-notename grob-pitch))
-                          (delta (modulo (- grob-name tonic-name) 7))
-                          (note-names
-                           (make-vector 7 (number->string (1+ delta)))))
-                     (ly:grob-set-property! grob 'note-names note-names))))))))
+   (make-engraver
+    (acknowledgers
+     ((note-head-interface engraver grob source-engraver)
+      (let* ((context (ly:translator-context engraver))
+	     (tonic-pitch (ly:context-property context 'tonic))
+	     (tonic-name (ly:pitch-notename tonic-pitch))
+	     (grob-pitch
+	      (ly:event-property (event-cause grob) 'pitch))
+	     (grob-name (ly:pitch-notename grob-pitch))
+	     (delta (modulo (- grob-name tonic-name) 7))
+	     (note-names
+	      (make-vector 7 (number->string (1+ delta)))))
+	(ly:grob-set-property! grob 'note-names note-names))))))
 
 #(set-global-staff-size 26)
 
diff --git a/input/regression/scheme-engraver-instance.ly b/input/regression/scheme-engraver-instance.ly
index d78e85a5db..fa32f95200 100644
--- a/input/regression/scheme-engraver-instance.ly
+++ b/input/regression/scheme-engraver-instance.ly
@@ -8,7 +8,7 @@
 
 }
 
-\version "2.14.0"
+\version "2.15.31"
 
 \layout {
   \context {
@@ -19,14 +19,14 @@
          (set! instance-counter (1+ instance-counter))
          (let ((instance-id instance-counter)
                (private-note-counter 0))
-           `((listeners
-              (note-event
-               . ,(lambda (engraver event)
-                    (set! private-note-counter (1+ private-note-counter))
-                    (let ((text (ly:engraver-make-grob engraver 'TextScript event)))
-                      (ly:grob-set-property! text 'text
-                                             (format #f "~a.~a" instance-id
-                                                     private-note-counter))))))))))
+	   (make-engraver
+	    (listeners
+              ((note-event engraver event)
+	       (set! private-note-counter (1+ private-note-counter))
+	       (let ((text (ly:engraver-make-grob engraver 'TextScript event)))
+		 (ly:grob-set-property! text 'text
+					(format #f "~a.~a" instance-id
+						private-note-counter)))))))))
   }
 }
 
diff --git a/input/regression/scheme-engraver.ly b/input/regression/scheme-engraver.ly
index 115429f90c..0be6f0d947 100644
--- a/input/regression/scheme-engraver.ly
+++ b/input/regression/scheme-engraver.ly
@@ -5,68 +5,49 @@
 
 }
 
-\version "2.14.0"
+\version "2.15.31"
 
 \layout {
   \context {
     \Voice
     \consists
-    #(list
-      (cons 'initialize
-       (lambda (trans)
-	(display (list "initialize"
-		  (ly:context-current-moment
-		   (ly:translator-context trans)) "\n") (current-error-port))))
-      (cons 'start-translation-timestep
-       (lambda (trans)
-	(display (list "start-trans"
-		  (ly:context-current-moment
-		   (ly:translator-context trans)) "\n") (current-error-port))))
-      (cons 'listeners
-       (list
-	(cons 'rest-event (lambda (engraver event)
-			   (let*
-			    ((x (ly:engraver-make-grob engraver 'TextScript event)))
-			    (display (list "caught event" event "\ncreate:\n" x "\n") (current-error-port))
-			    (ly:grob-set-property! x 'text "hi"))
-			   ))
-       ))
-      (cons 'acknowledgers
-       (list
-	(cons 'note-head-interface
-	 (lambda (engraver grob source-engraver)
-	  (display (list "saw head: " grob " coming from " source-engraver) (current-error-port))
-	  ))
-	))
-      (cons 'end-acknowledgers
-       (list
-	(cons 'beam-interface
-	 (lambda (engraver grob source-engraver)
-	  (display (list "saw end of beam: " grob " coming from " source-engraver) (current-error-port))
-	  ))
-	))
-      (cons 'process-music
-       (lambda (trans)
-	(display (list "process-music"
-		  (ly:context-current-moment
-		   (ly:translator-context trans)) "\n") (current-error-port))))
-      (cons 'process-acknowledged
-       (lambda (trans)
-	(display (list "process-acknowledged"
-		  (ly:context-current-moment
-		   (ly:translator-context trans)) "\n") (current-error-port))))
-      (cons 'stop-translation-timestep
-       (lambda (trans)
-	(display (list "stop-trans"
-		  (ly:context-current-moment
-		   (ly:translator-context trans)) "\n") (current-error-port))))
-      (cons 'finalize
-       (lambda (trans)
-	(display (list "finalize"
-		  (ly:context-current-moment
-		   (ly:translator-context trans)) "\n") (current-error-port))))
-    )
-
+    #(make-engraver
+      ((initialize trans)
+       (display (list "initialize"
+		      (ly:context-current-moment
+		       (ly:translator-context trans)) "\n") (current-error-port)))
+      ((start-translation-timestep trans)
+       (display (list "start-trans"
+		      (ly:context-current-moment
+		       (ly:translator-context trans)) "\n") (current-error-port)))
+      (listeners
+       ((rest-event engraver event)
+	(let*
+	    ((x (ly:engraver-make-grob engraver 'TextScript event)))
+	  (display (list "caught event" event "\ncreate:\n" x "\n") (current-error-port))
+	  (ly:grob-set-property! x 'text "hi"))))
+      (acknowledgers
+       ((note-head-interface engraver grob source-engraver)
+	(display (list "saw head: " grob " coming from " source-engraver) (current-error-port))))
+      (end-acknowledgers
+       ((beam-interface engraver grob source-engraver)
+	(display (list "saw end of beam: " grob " coming from " source-engraver) (current-error-port))))
+      ((process-music trans)
+       (display (list "process-music"
+		      (ly:context-current-moment
+		       (ly:translator-context trans)) "\n") (current-error-port)))
+      ((process-acknowledged trans)
+       (display (list "process-acknowledged"
+		      (ly:context-current-moment
+		       (ly:translator-context trans)) "\n") (current-error-port)))
+      ((stop-translation-timestep trans)
+       (display (list "stop-trans"
+		      (ly:context-current-moment
+		       (ly:translator-context trans)) "\n") (current-error-port)))
+      ((finalize trans)
+       (display (list "finalize"
+		      (ly:context-current-moment
+		       (ly:translator-context trans)) "\n") (current-error-port))))
 		}}
 
 
diff --git a/input/regression/scheme-text-spanner.ly b/input/regression/scheme-text-spanner.ly
index 6541f05a34..c0204d55c7 100644
--- a/input/regression/scheme-text-spanner.ly
+++ b/input/regression/scheme-text-spanner.ly
@@ -1,4 +1,4 @@
-\version "2.14.0"
+\version "2.15.31"
 
 \header {
   texidoc = "Use @code{define-event-class}, scheme engraver methods,
@@ -119,64 +119,58 @@ schemeTextSpannerEngraver =
          (finished '())
          (current-event '())
          (event-drul '(() . ())))
-     (list (cons 'listeners
-                 (list (cons 'scheme-text-span-event
-                             (lambda (engraver event)
-                               (if (= START (ly:event-property event 'span-direction))
-                                   (set-car! event-drul event)
-                                   (set-cdr! event-drul event))))))
-           (cons 'acknowledgers
-                 (list (cons 'note-column-interface
-                             (lambda (engraver grob source-engraver)
-                               (if (ly:spanner? span)
-                                   (begin
-                                     (ly:pointer-group-interface::add-grob span 'note-columns grob)
-                                     (add-bound-item span grob)))
-                               (if (ly:spanner? finished)
-                                   (begin
-                                     (ly:pointer-group-interface::add-grob finished 'note-columns grob)
-                                     (add-bound-item finished grob)))))))
-           (cons 'process-music
-                 (lambda (trans)
-                   (if (ly:stream-event? (cdr event-drul))
-                       (if (null? span)
-                           (ly:warning "You're trying to end a scheme text spanner but you haven't started one.")
-                           (begin (set! finished span)
-                                  (ly:engraver-announce-end-grob trans finished current-event)
-                                  (set! span '())
-                                  (set! current-event '())
-                                  (set-cdr! event-drul '()))))
-                   (if (ly:stream-event? (car event-drul))
-                       (begin (set! current-event (car event-drul))
-                              (set! span (ly:engraver-make-grob trans 'SchemeTextSpanner current-event))
-                              (set-axis! span Y)
-                              (set-car! event-drul '())))))
-           (cons 'stop-translation-timestep
-                 (lambda (trans)
-                   (if (and (ly:spanner? span)
-                            (null? (ly:spanner-bound span LEFT)))
-                       (set! (ly:spanner-bound span LEFT)
-                             (ly:context-property context 'currentMusicalColumn)))
-                   (if (ly:spanner? finished)
-                       (begin
-                         (if (null? (ly:spanner-bound finished RIGHT))
-                             (set! (ly:spanner-bound finished RIGHT)
-                                   (ly:context-property context 'currentMusicalColumn)))
-                         (set! finished '())
-                         (set! event-drul '(() . ()))))))
-           (cons 'finalize
-                 (lambda (trans)
-                   (if (ly:spanner? finished)
-                       (begin
-                         (if (null? (ly:spanner-bound finished RIGHT))
-                             (set! (ly:spanner-bound finished RIGHT)
-                                   (ly:context-property context 'currentMusicalColumn)))
-                         (set! finished '())))
-                   (if (ly:spanner? span)
-                       (begin
-                         (ly:warning "I think there's a dangling scheme text spanner :-(")
-                         (ly:grob-suicide! span)
-                         (set! span '()))))))))
+     (make-engraver
+      (listeners ((scheme-text-span-event engraver event)
+		  (if (= START (ly:event-property event 'span-direction))
+		      (set-car! event-drul event)
+		      (set-cdr! event-drul event))))
+      (acknowledgers ((note-column-interface engraver grob source-engraver)
+		      (if (ly:spanner? span)
+			  (begin
+			    (ly:pointer-group-interface::add-grob span 'note-columns grob)
+			    (add-bound-item span grob)))
+		      (if (ly:spanner? finished)
+			  (begin
+			    (ly:pointer-group-interface::add-grob finished 'note-columns grob)
+			    (add-bound-item finished grob)))))
+      ((process-music trans)
+       (if (ly:stream-event? (cdr event-drul))
+	   (if (null? span)
+	       (ly:warning "You're trying to end a scheme text spanner but you haven't started one.")
+	       (begin (set! finished span)
+		      (ly:engraver-announce-end-grob trans finished current-event)
+		      (set! span '())
+		      (set! current-event '())
+		      (set-cdr! event-drul '()))))
+       (if (ly:stream-event? (car event-drul))
+	   (begin (set! current-event (car event-drul))
+		  (set! span (ly:engraver-make-grob trans 'SchemeTextSpanner current-event))
+		  (set-axis! span Y)
+		  (set-car! event-drul '()))))
+      ((stop-translation-timestep trans)
+       (if (and (ly:spanner? span)
+		(null? (ly:spanner-bound span LEFT)))
+	   (set! (ly:spanner-bound span LEFT)
+		 (ly:context-property context 'currentMusicalColumn)))
+       (if (ly:spanner? finished)
+	   (begin
+	     (if (null? (ly:spanner-bound finished RIGHT))
+		 (set! (ly:spanner-bound finished RIGHT)
+		       (ly:context-property context 'currentMusicalColumn)))
+	     (set! finished '())
+	     (set! event-drul '(() . ())))))
+      ((finalize trans)
+       (if (ly:spanner? finished)
+	   (begin
+	     (if (null? (ly:spanner-bound finished RIGHT))
+		 (set! (ly:spanner-bound finished RIGHT)
+		       (ly:context-property context 'currentMusicalColumn)))
+	     (set! finished '())))
+       (if (ly:spanner? span)
+	   (begin
+	     (ly:warning "I think there's a dangling scheme text spanner :-(")
+	     (ly:grob-suicide! span)
+	     (set! span '())))))))
 
 schemeTextSpannerStart =
 #(make-span-event 'SchemeTextSpanEvent START)
diff --git a/ly/event-listener.ly b/ly/event-listener.ly
index 71d560b075..20615e8c2a 100644
--- a/ly/event-listener.ly
+++ b/ly/event-listener.ly
@@ -32,7 +32,7 @@
 
 
 
-\version "2.15.0"
+\version "2.15.31"
 
 %%%% Helper functions
 
@@ -205,21 +205,19 @@ optionally outputs to the console as well."
 \layout {
   \context {
   \Voice
-  \consists #(list
-              (cons 'listeners
-                    (list
-                     (cons 'tempo-change-event format-tempo)
-                     (cons 'rest-event format-rest)
-                     (cons 'note-event format-note)
-                     (cons 'articulation-event format-articulation)
-                     (cons 'text-script-event format-text)
-                     (cons 'slur-event format-slur)
-                     (cons 'breathing-event format-breathe)
-                     (cons 'dynamic-event format-dynamic)
-                     (cons 'crescendo-event format-cresc)
-                     (cons 'decrescendo-event format-decresc)
-                     (cons 'text-span-event format-textspan)
-                     (cons 'tie-event format-tie)
-                     )))
+  \consists #(make-engraver
+              (listeners
+	       (tempo-change-event . format-tempo)
+	       (rest-event . format-rest)
+	       (note-event . format-note)
+	       (articulation-event . format-articulation)
+	       (text-script-event . format-text)
+	       (slur-event . format-slur)
+	       (breathing-event . format-breathe)
+	       (dynamic-event . format-dynamic)
+	       (crescendo-event . format-cresc)
+	       (decrescendo-event . format-decresc)
+	       (text-span-event . format-textspan)
+	       (tie-event . format-tie)))
   }
 }