Fix a segfault caused by improper initialization of SCM.

[lilypond.git] / scm / ly-syntax-constructors.scm

diff --git a/scm/ly-syntax-constructors.scm b/scm/ly-syntax-constructors.scm
index 92276e745f1ca9fbc31e367b6d02fa7633e82d2e..171cee12407e8bbb2ebf1f0c87b25d3ed3e0ce3f 100644 (file)
--- a/scm/ly-syntax-constructors.scm
+++ b/scm/ly-syntax-constructors.scm
@@ -1,6 +1,6 @@
 ;;;; This file is part of LilyPond, the GNU music typesetter.
 ;;;;
-;;;; Copyright (C) 2006--2010 Erik Sandberg <mandolaerik@gmail.com>
+;;;; Copyright (C) 2006--2011 Erik Sandberg <mandolaerik@gmail.com>
 ;;;;
 ;;;; LilyPond is free software: you can redistribute it and/or modify
 ;;;; it under the terms of the GNU General Public License as published by
@@ -89,29 +89,34 @@
   (make-music 'TransposedMusic
              'element (ly:music-transpose music pitch)))
 
-(define-ly-syntax-simple (tempo text duration tempo)
-  (let ((props (list
-                 (make-property-set 'tempoWholesPerMinute
-                       (ly:moment-mul (ly:make-moment tempo 1)
-                                      (ly:duration-length duration)))
-                 (make-property-set 'tempoUnitDuration duration)
-                 (make-property-set 'tempoUnitCount tempo))))
-    (set! props (cons 
-            (if text (make-property-set 'tempoText text)
-                     (make-property-unset 'tempoText)) 
-            props))
-    (context-spec-music
-      (make-sequential-music props)
-      'Score)))
-
-(define-ly-syntax-simple (tempoText text)
-  (context-spec-music
-   (make-sequential-music
-    (list
-     (make-property-unset 'tempoUnitDuration)
-     (make-property-unset 'tempoUnitCount)
-     (make-property-set 'tempoText text)))
-   'Score))
+(define-ly-syntax (tempo parser location text . rest)
+  (let* ((unit (and (pair? rest)
+                   (car rest)))
+        (count (and unit
+                    (cadr rest)))
+        (range-tempo? (pair? count))
+        (tempo-change (make-music 'TempoChangeEvent
+                                  'origin location
+                                  'text text
+                                  'tempo-unit unit
+                                  'metronome-count count))
+        (tempo-set
+         (and unit
+              (context-spec-music
+               (make-property-set 'tempoWholesPerMinute
+                                  (ly:moment-mul
+                                   (ly:make-moment
+                                    (if range-tempo?
+                                        (round (/ (+ (car count) (cdr count))
+                                                  2))
+                                        count)
+                                    1)
+                                   (ly:duration-length unit)))
+               'Score))))
+
+    (if tempo-set
+       (make-sequential-music (list tempo-change tempo-set))
+       tempo-change)))
 
 (define-ly-syntax-simple (skip-music dur)
   (make-music 'SkipMusic