X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fcontext-def.cc;h=227bc8b3e9ca5c2df6d18e1917c4b8593c9dff66;hb=1f0dbc5ce41f4fa5aecc2994452b58ba42ca558c;hp=f4023a09a110833cb56ad13f83d8c2dbf75a4059;hpb=00e3e15364b9d3c94cda1bcab9f889bb95f6832d;p=lilypond.git

diff --git a/lily/context-def.cc b/lily/context-def.cc
index f4023a09a1..227bc8b3e9 100644
--- a/lily/context-def.cc
+++ b/lily/context-def.cc
@@ -1,9 +1,20 @@
 /*
-  translator-def.cc -- implement Context_def
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 2000--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
-  (c) 2000--2007 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
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 /* TODO: should junk this class an replace by
@@ -123,14 +134,9 @@ Context_def::add_context_mod (SCM mod)
   if (ly_symbol2scm ("default-child") == tag)
     default_child_ = sym;
   else if (ly_symbol2scm ("consists") == tag
-	   || ly_symbol2scm ("consists-end") == tag
 	   || ly_symbol2scm ("remove") == tag)
     {
-      if (!get_translator (sym))
-	error (_f ("program has no such type: `%s'",
-		   ly_symbol2string (sym).c_str ()));
-      else
-	translator_mods_ = scm_cons (scm_list_2 (tag, sym), translator_mods_);
+      translator_mods_ = scm_cons (scm_list_2 (tag, sym), translator_mods_);
     }
   else if (ly_symbol2scm ("accepts") == tag
 	   || ly_symbol2scm ("denies") == tag)
@@ -193,12 +199,40 @@ Context_def::get_default_child (SCM user_mod) const
   return name;
 }
 
+/*
+  Given a name of a context that we want to create, finds a list of context
+  definitions such that:
+   - the first element in the list defines a context that is a valid child of
+     the context defined by this Context_def
+   - each subsequent element in the list defines a context that is a valid child
+     of the the context defined by the preceding element in the list
+   - the last element in the list defines a context with the given name
+
+  The ADDITIONAL_ACCEPTS parameter is a list of additional contexts that this
+  specific context def (but not any of the child context defs) should accept.
+*/
+vector<Context_def *>
+Context_def::path_to_acceptable_context (SCM type_sym,
+					 Output_def *odef,
+					 SCM additional_accepts) const
+{
+  set<const Context_def *> seen;
+  return internal_path_to_acceptable_context (type_sym, odef, additional_accepts, &seen);
+}
+
+/*
+The SEEN parameter is a set which keeps track of visited contexts, allowing
+contexts of the same type to be nested.
+*/
 vector<Context_def*>
-Context_def::path_to_acceptable_context (SCM type_sym, Output_def *odef) const
+Context_def::internal_path_to_acceptable_context (SCM type_sym,
+						  Output_def *odef,
+						  SCM additional_accepts,
+						  set<const Context_def *> *seen) const
 {
   assert (scm_is_symbol (type_sym));
 
-  SCM accepted = get_accepted (SCM_EOL);
+  SCM accepted = get_accepted (additional_accepts);
 
   vector<Context_def*> accepteds;
   for (SCM s = accepted; scm_is_pair (s); s = scm_cdr (s))
@@ -218,20 +252,25 @@ Context_def::path_to_acceptable_context (SCM type_sym, Output_def *odef) const
 	}
     }
 
+  seen->insert (this);
   vsize best_depth = INT_MAX;
   for (vsize i = 0; i < accepteds.size (); i++)
     {
       Context_def *g = accepteds[i];
 
-      vector<Context_def*> result
-	= g->path_to_acceptable_context (type_sym, odef);
-      if (result.size () && result.size () < best_depth)
+      if (!seen->count (g))
 	{
-	  best_depth = result.size ();
-	  result.insert (result.begin (), g);
-	  best_result = result;
+	  vector<Context_def*> result
+	    = g->internal_path_to_acceptable_context (type_sym, odef, SCM_EOL, seen);
+	  if (result.size () && result.size () < best_depth)
+	    {
+	      best_depth = result.size ();
+	      result.insert (result.begin (), g);
+	      best_result = result;
+	    }
 	}
     }
+  seen->erase (this);
 
   return best_result;
 }
@@ -253,7 +292,8 @@ Context_def::get_translator_names (SCM user_mod) const
 
       if (ly_symbol2scm ("consists") == tag)
 	l1 = scm_cons (arg, l1);
-      else if (ly_symbol2scm ("remove") == tag)
+      else if (ly_symbol2scm ("remove") == tag
+	       && get_translator (arg))
 	l1 = scm_delete_x (arg, l1);
     }