X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fmusic-function-scheme.cc;h=93c7e0fbc4773cbc121ca45779b1c71db26c8c96;hb=1265d01b03ae4cbf1913f51a063cda8dc2842cf0;hp=828929994a93515b22840709f5a5efdcda65d28c;hpb=c5a3f0c024f4cb629811cff9eb04abff36e94138;p=lilypond.git

diff --git a/lily/music-function-scheme.cc b/lily/music-function-scheme.cc
index 828929994a..93c7e0fbc4 100644
--- a/lily/music-function-scheme.cc
+++ b/lily/music-function-scheme.cc
@@ -1,29 +1,44 @@
 #include "music-function.hh"
 
 LY_DEFINE (ly_music_function_p, "ly:music-function?", 1, 0, 0,
-	   (SCM x),
-	   "Is @var{x} an @code{music-function}?")
+           (SCM x),
+           "Is @var{x} a @code{music-function}?")
 {
   return is_music_function (x) ? SCM_BOOL_T : SCM_BOOL_F;
 }
-		 
+
 LY_DEFINE (ly_music_function_extract, "ly:music-function-extract", 1, 0, 0,
-	   (SCM x),
-	   "Return the Scheme function inside @var{x}")
+           (SCM x),
+           "Return the Scheme function inside@tie{}@var{x}.")
 {
   LY_ASSERT_TYPE (is_music_function, x, 1);
-  
-  return SCM_CELL_OBJECT_1(x);
+
+  return SCM_CELL_OBJECT_1 (x);
 }
 
 LY_DEFINE (ly_make_music_function, "ly:make-music-function", 2, 0, 0,
-	   (SCM signature, SCM func),
-	   "Make a function to process music, to be used for the "
-	   "parser. @code{func} is the function, and @code{signature} describes "
-	   "Its arguments. @code{signature} is a list containing either "
-	   "@code{ly:music?} predicates or other type predicates.")
+           (SCM signature, SCM func),
+           "Make a function to process music, to be used for the"
+           " parser.  @var{func} is the function, and @var{signature}"
+           " describes its arguments.  @var{signature}'s cdr is a list"
+           " containing either @code{ly:music?} predicates or other type"
+           " predicates.  Its car is the syntax function to call.")
 {
-  LY_ASSERT_TYPE (ly_is_procedure, func, 1);
-  return  make_music_function (signature, func);
+  LY_ASSERT_TYPE (ly_is_list, signature, 1);
+  LY_ASSERT_TYPE (ly_is_procedure, func, 2);
+  int n = 0;
+  for (SCM p = signature; scm_is_pair (p); p = scm_cdr (p), ++n)
+    {
+      SCM proc = scm_car (p);
+      if (scm_is_pair (proc))
+        proc = scm_car (proc);
+      if (scm_is_false (scm_procedure_p (proc)))
+        {
+          scm_wrong_type_arg_msg ("music-function", n, p,
+                                  "music function predicate");
+        }
+    }
+
+  return make_music_function (signature, func);
 }