--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TreeEditor.java	Mon Jan 07 23:22:36 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TreeEditor.java	Thu Jan 10 23:22:42 2013 +0900
@@ -1,19 +1,18 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store;
 
 import java.nio.ByteBuffer;
-
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.trasnformer.NodeEditor;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
 
 public interface TreeEditor
 {
 	public TraversableTree getTree();
-	public TreeEditResult appendChild(NodePath _path,int _pos);
-	public TreeEditResult deleteChild(NodePath _path,int _pos);
-	
-	public TreeEditResult putAttribute(NodePath _path,String _key,ByteBuffer _value);
-	public TreeEditResult deleteAttribute(NodePath _path,String _key);
-	
-	public TreeEditResult edit(NodePath _path,NodeEditor _transformer);
+	public Either<Error,TreeEditor> appendChild(NodePath _path,int _pos);
+	public Either<Error,TreeEditor> deleteChild(NodePath _path,int _pos);
+	public Either<Error,TreeEditor> putAttribute(NodePath _path,String _key,ByteBuffer _value);
+	public Either<Error,TreeEditor> deleteAttribute(NodePath _path,String _key);
+	public Either<Error,TreeEditor> edit(NodePath _path,NodeEditor _transformer);
 	
 	public boolean success();
 }