/* This file is part of the Joshua Machine Translation System.
 * 
 * Joshua is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */
package joshua.decoder.hypergraph;

import java.util.ArrayList;
import java.util.List;

import joshua.corpus.Vocabulary;
import joshua.decoder.ff.tm.Rule;

/**
 * @author Matt Post <post@cs.jhu.edu>
 */

/**
 * This class visits every node in a forest using a depth-first,
 * preorder traversal, applying the WalkerFunction to each node.  It
 * would be easy to add other traversals if the demand arose.
 */
class ForestWalker {
    public static void walk(HGNode node, WalkerFunction walker) {
        // apply the function
        walker.apply(node);

        for (HyperEdge edge : node.getHyperEdges()) {
			for (HGNode tailNode : edge.getAntNodes()) {
				walk(tailNode, walker);
			}
		}
    }
}

@@ -1348,24 +1348,57 @@
 node);%0A%0A
-        
+%09%09if (node.getHyperEdges() != null) %7B%0A%09%09%09
 for (Hyp
@@ -1431,24 +1431,64 @@
 rEdges()) %7B%0A
+%09%09%09%09if (edge.getAntNodes() != null) %7B%0A%09%09
 %09%09%09for (HGNo
@@ -1527,16 +1527,18 @@
 ) %7B%0A%09%09%09%09
+%09%09
 walk(tai
@@ -1553,16 +1553,29 @@
 alker);%0A
+%09%09%09%09%09%7D%0A%09%09%09%09%7D%0A
 %09%09%09%7D%0A%09%09%7D

check for null incoming hyperedges and tail nodes