* lily/beam.cc (least_squares): Add comment.

[lilypond.git] / lily / thread-devnull-engraver.cc

diff --git a/lily/thread-devnull-engraver.cc b/lily/thread-devnull-engraver.cc
index 14f6754e0ea23cd0c0e43f2459b43cb842a0e699..19f4621f43e63eaa5849d663d348f64c02ceeded 100644 (file)
--- a/lily/thread-devnull-engraver.cc
+++ b/lily/thread-devnull-engraver.cc
@@ -3,7 +3,7 @@
 
   source file of the GNU LilyPond music typesetter
   
-  (c) 2000 Jan Nieuwenhuizen <janneke@gnu.org>
+  (c) 2000--2002 Jan Nieuwenhuizen <janneke@gnu.org>
 */
 
 #include "engraver.hh"
@@ -14,29 +14,50 @@
 class Thread_devnull_engraver : public Engraver
 {
 public:
-  VIRTUAL_COPY_CONS (Translator);
+  TRANSLATOR_DECLARATIONS(Thread_devnull_engraver);
   
 protected:
   virtual void acknowledge_grob (Grob_info);
 };
 
-ADD_THIS_TRANSLATOR (Thread_devnull_engraver);
+
 
 void
 Thread_devnull_engraver::acknowledge_grob (Grob_info i)
 {
   SCM s = get_property ("devNullThread");
+
 #if 0
-  /* No need */
-  if (gh_equal_p (s, ly_symbol2scm ("never")))
+  /* No need, next if will never be true */
+  if (s == ly_symbol2scm ("never"))
     return;
 #endif
 
-  if (gh_equal_p (s, ly_symbol2scm ("allways"))
-      || (gh_equal_p (s, ly_symbol2scm ("unisolo"))
-         && daddy_trans_l_->id_str_.left_str (3) == "two"
-         && (to_boolean (get_property ("unison"))
-             || to_boolean (get_property ("unisilence")))
-         && to_boolean (get_property ("soloADue"))))
-    i.elem_l_->suicide ();
+  if (s == ly_symbol2scm ("always")
+      || (s == SCM_EOL
+         && to_boolean (get_property ("soloADue"))
+         && ((daddy_trans_->id_string_.left_string (3) == "two"
+              && (to_boolean (get_property ("unison"))
+                  || to_boolean (get_property ("unisilence"))))
+
+             /* Maybe this should be optional? */
+             || to_boolean (get_property ("othersolo")))))
+    {
+      i.grob_->suicide ();
+    }
 }
+Thread_devnull_engraver::Thread_devnull_engraver(){}
+
+ENTER_DESCRIPTION(Thread_devnull_engraver,
+/* descr */       "Kill elements whenever we are Voice called `two' and either
+unison, unisilence or soloADue is set.@footnote{On unix systems, the
+file @file{/dev/null} is special device: anything written to it is
+discarded.}. This engraver works closely together with the part
+combiner.  When the part combiner notices that two threads are
+identical, it tells the @code{Thread_devnull_engraver} to discard
+everything in the second thread.
+",
+/* creats*/       "",
+/* acks  */       "grob-interface",
+/* reads */       "",
+/* write */       "");