--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/DefaultTraversableTree.java	Mon Jan 14 03:22:59 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/DefaultTraversableTree.java	Mon Jan 14 04:07:15 2013 +0900
@@ -3,30 +3,27 @@
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Tree;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.TraversableTree;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser.Evaluator;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser.Traversal;
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser.TraverseEvaluator;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser.Traverser;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
 
 public class DefaultTraversableTree implements TraversableTree
 {
 	private final Tree tree;
-	private final Traverser traverser;
+	private final Traverser<Node> traverser;
 	
-	public DefaultTraversableTree(Tree _tree,Traverser _traverser)
+	public DefaultTraversableTree(Tree _tree,Traverser<Node> _traverser)
 	{
 		tree = _tree;
 		traverser = _traverser;
 	}
 
 	@Override
-	public Node getRoot()
+	public Either<Error,Traversal<Node>> traverse(Evaluator<Node> _e)
 	{
-		return tree.getRoot();
-	}
-
-	@Override
-	public Iterable<Traversal> traverse(TraverseEvaluator _e)
-	{
-		return traverser.traverse(tree,_e);
+		Node root = tree.getRoot();
+		return traverser.traverse(root,_e);
 	}
 }