# HG changeset patch
# User Shoshi TAMAKI
# Date 1358101379 -32400
# Node ID 075d6418e35948e0e2888bca72b0db07cc7b0e60
# Parent  1b448f9249ee9aa73f5953b00616078e4eeb6869
modified traverser

diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/core/Children.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/core/Children.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/core/Children.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,6 +1,6 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core;
 
-public interface Children extends Iterable<Node>
+public interface Children<T extends Node> extends Iterable<T>
 {
 	public int size();
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/core/Node.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/core/Node.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/core/Node.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,7 +1,12 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core;
 
-public interface Node
+public interface Node<T extends Node<T>>
 {
-	public Children getChildren();
+	public Children<T> getChildren();
 	public Attributes getAttributes();
 }
+
+interface Container<T>
+{
+	
+}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TraversableTree.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TraversableTree.java	Sun Jan 13 20:52:19 2013 +0900
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,9 +0,0 @@
-package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store;
-
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Tree;
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser.Traversable;
-
-public interface TraversableTree extends Tree , Traversable
-{
-
-}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TreeEditor.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TreeEditor.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/TreeEditor.java	Mon Jan 14 03:22:59 2013 +0900
@@ -7,7 +7,7 @@
 
 public interface TreeEditor
 {
-	public TraversableTree getTree();
+	public Tree getTree();
 	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);
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/DefaultChildren.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/DefaultChildren.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/DefaultChildren.java	Mon Jan 14 03:22:59 2013 +0900
@@ -69,8 +69,8 @@
 	}
 
 	@Override
-	public Iterator<Node> iterator()
+	public Iterator<EditableNode> iterator()
 	{
-		return (new IterableWrapper<Node>(children)).iterator();
+		return (new IterableWrapper<EditableNode>(children)).iterator();
 	}
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/logger/LoggingChildren.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/logger/LoggingChildren.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/impl/logger/LoggingChildren.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,7 +1,6 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.impl.logger;
 
 import java.util.Iterator;
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.operations.AppendChildAtOperation;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.operations.DeleteChildAtOperation;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.operations.Operation;
@@ -30,9 +29,9 @@
 	}
 
 	@Override
-	public Iterator<Node> iterator()
+	public Iterator<EditableNode> iterator()
 	{
-		IterableWrapper<Node> wrapper = new IterableWrapper<Node>(this);
+		IterableWrapper<EditableNode> wrapper = new IterableWrapper<EditableNode>(this);
 		return wrapper.iterator();
 	}
 
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/trasnformer/EditableChildren.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/trasnformer/EditableChildren.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/store/trasnformer/EditableChildren.java	Mon Jan 14 03:22:59 2013 +0900
@@ -5,7 +5,7 @@
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
 import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
 
-public interface EditableChildren extends Children
+public interface EditableChildren extends Children<EditableNode>
 {
 	public Either<Error,EditableNode> addNewChildAt(int _pos);
 	public Either<Error,EditableNode> deleteChildAt(int _pos);
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Children.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Children.java	Mon Jan 14 03:22:59 2013 +0900
@@ -0,0 +1,6 @@
+package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
+
+public interface Children<T> extends Iterable<T>
+{
+	public int size();
+}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultEvaluation.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultEvaluation.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultEvaluation.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,24 +1,24 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
 
-public class DefaultEvaluation implements Evaluation
+public class DefaultEvaluation<T extends Parent<T>> implements Evaluation<T>
 {
-	private final Evaluation.Result result;
-	private final TraverseEvaluator evaluator;
+	private final Result result;
+	private final Evaluator<T> evaluator;
 	
-	public DefaultEvaluation(Evaluation.Result _result,TraverseEvaluator _evaluator)
+	public DefaultEvaluation(Result _result,Evaluator<T> _evaluator)
 	{
 		result = _result;
 		evaluator = _evaluator;
 	}
 
 	@Override
-	public Evaluation.Result result()
+	public Result result()
 	{
 		return result;
 	}
 
 	@Override
-	public TraverseEvaluator evaluator()
+	public Evaluator<T> evaluator()
 	{
 		return evaluator;
 	}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultEvaluator.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultEvaluator.java	Mon Jan 14 03:22:59 2013 +0900
@@ -0,0 +1,33 @@
+package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
+
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.NodePath;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Pair;
+
+public class DefaultEvaluator<T extends Parent<T>> implements Evaluator<T>
+{
+	private final NodePath path;
+	
+	public DefaultEvaluator(NodePath _path)
+	{
+		path = _path;
+	}
+	
+	@Override
+	public Evaluation<T> evaluate(T _current,int _pos)
+	{
+		Pair<Integer,NodePath> pop = path.pop();
+		if(pop == null){
+			return new DefaultEvaluation<T>(Result.BREAK,null);
+		}
+		
+		DefaultEvaluator<T> nextEvaluator = new DefaultEvaluator<T>(pop.right());
+		int head = pop.left();
+		
+		Result result = Result.CONTINUE;
+		if(head == _pos){
+			result = Result.ACCEPT;
+		}
+		
+		return new DefaultEvaluation<T>(result,nextEvaluator);
+	}
+}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraversal.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraversal.java	Sun Jan 13 20:52:19 2013 +0900
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,20 +0,0 @@
-package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
-
-import java.util.Iterator;
-
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
-
-public class DefaultTraversal implements Traversal
-{
-	@Override
-	public Iterator<Node> iterator()
-	{
-		return null;
-	}
-
-	@Override
-	public Node destination()
-	{
-		return null;
-	}
-}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraverseEvaluator.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraverseEvaluator.java	Sun Jan 13 20:52:19 2013 +0900
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,30 +0,0 @@
-package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
-
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.store.NodePath;
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Pair;
-
-public class DefaultTraverseEvaluator implements TraverseEvaluator
-{
-	private final NodePath path;
-	
-	public DefaultTraverseEvaluator(NodePath _path)
-	{
-		path = _path;
-	}
-	
-	@Override
-	public Evaluation eval(Iterable<Node> _currentPosition,Node _child,int _pos)
-	{
-		Pair<Integer,NodePath> pop = path.pop();
-		DefaultTraverseEvaluator nextEvaluator = new DefaultTraverseEvaluator(pop.right());
-		int head = pop.left();
-		
-		Evaluation.Result result = Evaluation.Result.DENY_CONTINUE;
-		if(head == _pos){
-			result = Evaluation.Result.ACCEPT_BREAK;
-		}
-		
-		return new DefaultEvaluation(result,nextEvaluator);
-	}
-}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraverser.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraverser.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/DefaultTraverser.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,84 +1,88 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
 
 import java.util.Iterator;
-import fj.P;
-import fj.P2;
+
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.DefaultEither;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
 import fj.data.List;
-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.util.IterableConverter;
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.IterableConverter.Converter;
 
-public class DefaultTraverser implements Traverser
+public class DefaultTraverser<T extends Parent<T>> implements Traverser<T>
 {
 	@Override
-	public Iterable<Traversal> traverse(Tree _tree, TraverseEvaluator _evaluator)
+	public Either<Error,Traversal<T>> traverse(final T _root,Evaluator<T> _evaluator)
 	{
-		Node root = _tree.getRoot();
-		
-		List<Node> current = List.nil();
-		TraverseEvaluator evaluator = _evaluator;
-		
-		List<List<Node>> totalResult = _traverse(current,root,evaluator);
-		
-		Converter<Traversal,List<Node>> converter = new IterableConverter.Converter<Traversal,List<Node>>(){
+		Children<T> wrapper = new Children<T>(){
+			@Override
+			public Iterator<T> iterator(){
+				List<T> list = List.nil();
+				return list.cons(_root).iterator();
+			}
 			@Override
-			public Traversal conv(final List<Node> _b)
-			{
-				Traversal t = new Traversal(){
-					@Override
-					public Iterator<Node> iterator(){
-						return _b.iterator();
-					}
+			public int size(){
+				return 1;
+			}
+		};
+		
+		Either<Error,List<T>> ret = _traverse(wrapper,_evaluator);
+		if(ret.isA()){
+			return DefaultEither.newA(ret.a());
+		}
+		
+		final Iterable<T> iterable = ret.b();
+		final T destination = ret.b().last();
+		
+		Traversal<T> traversal = new Traversal<T>(){
+			@Override
+			public Iterator<T> iterator(){
+				return iterable.iterator();
+			}
 
-					@Override
-					public Node destination() {
-						return _b.last();
-					}
-					
-				};
-				
-				return t;
+			@Override
+			public T destination(){
+				return destination;
 			}
 		};
 		
-		return new IterableConverter<Traversal,List<Node>>(totalResult,converter);
+		return DefaultEither.newB(traversal);
 	}
 	
-	private List<List<Node>> _traverse(List<Node> _path,Node _current,TraverseEvaluator _evaluator)
+	private Either<Error,List<T>> _traverse(Children<T> _chs,Evaluator<T> _evaluator)
 	{
-		List<Node> currentPath = _path.snoc(_current);
-		
 		int pos = 0;
-		List<P2<Node,Evaluation>> accepted = List.nil();
-		
-		for(Node child : _current.getChildren()){
-			Evaluation e = _evaluator.eval(currentPath,child,pos);
-			Evaluation.Result result = e.result();
+		for(T ch : _chs){
+			Evaluation<T> e = _evaluator.evaluate(ch,pos);
+			Result r = e.result();
+			if(r == Result.ACCEPT){
+				return _accept(ch,e.evaluator());
+			}
 			
-			if(result == Evaluation.Result.ACCEPT_CONTINUE ||
-					result == Evaluation.Result.ACCEPT_BREAK){
-				accepted = accepted.snoc(P.p(child,e));
+			if(r == Result.BREAK){
+				break;
+			}
+			
+			if(r == Result.CONTINUE){
+				continue;
 			}
 			
-			if(result == Evaluation.Result.DENY_BREAK || 
-					result == Evaluation.Result.ACCEPT_BREAK){
-				break;
-			}
+			return DefaultEither.newA(TraverserError.UNDEFINED_OPERATOR);
 		}
 		
-		List<List<Node>> totalResult = List.nil();
-		for(P2<Node,Evaluation> next : accepted){
-			Node node = next._1();
-			TraverseEvaluator evaluator = next._2().evaluator();
-			List<List<Node>> result = _traverse(currentPath,node,evaluator);
-			
-			
-			for(List<Node> list : result){
-				totalResult = totalResult.snoc(list.cons(_current));
-			}
+		List<T> empty = List.nil();
+		Either<Error,List<T>> ret = DefaultEither.newB(empty);
+		return ret;
+	}
+	
+	private Either<Error,List<T>> _accept(T _current,Evaluator<T> _evaluator)
+	{
+		Children<T> chs = _current.children();
+		Either<Error,List<T>> either = _traverse(chs,_evaluator);
+		if(either.isA()){
+			return either;
 		}
 		
-		return totalResult;
+		List<T> list = either.b();
+		List<T> newList = list.cons(_current);
+		return DefaultEither.newB(newList);
 	}
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Evaluation.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Evaluation.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Evaluation.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,7 +1,7 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
 
-public interface Evaluation
+public interface Evaluation<T extends Parent<T>>
 {
 	public Result result();
-	public Evaluator evaluator();
+	public Evaluator<T> evaluator();
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Evaluator.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Evaluator.java	Mon Jan 14 03:22:59 2013 +0900
@@ -0,0 +1,6 @@
+package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
+
+public interface Evaluator<T extends Parent<T>>
+{
+	public Evaluation<T> evaluate(T _current,int _pos);
+}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Parent.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Parent.java	Mon Jan 14 03:22:59 2013 +0900
@@ -0,0 +1,6 @@
+package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
+
+public interface Parent<T>
+{
+	public Children<T> children();
+}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Result.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Result.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Result.java	Mon Jan 14 03:22:59 2013 +0900
@@ -6,4 +6,8 @@
 	public static final Result ACCEPT = new Result();
 	public static final Result CONTINUE = new Result();
 	public static final Result BREAK = new Result();
+	
+	private Result()
+	{
+	}
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traversable.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traversable.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traversable.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,6 +1,8 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
 
-public interface Traversable
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
+
+public interface Traversable<T extends Parent<T>>
 {
-	public Iterable<Traversal> traverse(TraverseEvaluator _e);
+	public Either<Error,Traversal<T>> traverse(Evaluator<T> _e);
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traversal.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traversal.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traversal.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,8 +1,6 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
 
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
-
-public interface Traversal<T extends Node> extends Iterable<T>
+public interface Traversal<T extends Parent<T>> extends Iterable<T>
 {
 	public T destination();
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/TraverseEvaluator.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/TraverseEvaluator.java	Sun Jan 13 20:52:19 2013 +0900
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,13 +0,0 @@
-package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
-
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
-
-public interface Evaluator
-{
-	public static final long ACCEPT_AND_CONTINUE = 0;
-	public static final long DENY_AND_CONTINUE = 1;
-	public static final long ACCEPT_AND_BREAK = 2;
-	public static final long DENY_AND_BREAK = 3;
-	
-	public Evaluation evaluate(Iterable<Node> _currentPosition,Node _child,int _pos);
-}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traverser.java
--- a/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traverser.java	Sun Jan 13 20:52:19 2013 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/Traverser.java	Mon Jan 14 03:22:59 2013 +0900
@@ -1,8 +1,9 @@
 package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
 
-import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.core.Node;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Either;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
 
-public interface Traverser<T extends Node>
+public interface Traverser<T extends Parent<T>>
 {
-	public Traversal traverse(T _root,TraverseEvaluator _evaluator);
+	public Either<Error,Traversal<T>> traverse(T _root,Evaluator<T> _evaluator);
 }
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/TraverserError.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/traverser/TraverserError.java	Mon Jan 14 03:22:59 2013 +0900
@@ -0,0 +1,9 @@
+package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.traverser;
+
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.DefaultError;
+import jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util.Error;
+
+public class TraverserError
+{
+	public static final Error UNDEFINED_OPERATOR = new DefaultError();
+}
diff -r 1b448f9249ee -r 075d6418e359 src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/util/Container.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/jp/ac/u_ryukyu/ie/cr/shoshi/jungle/util/Container.java	Mon Jan 14 03:22:59 2013 +0900
@@ -0,0 +1,47 @@
+package jp.ac.u_ryukyu.ie.cr.shoshi.jungle.util;
+
+import fj.data.List;
+
+public interface Container<T>
+{
+	public T get();
+	public List<Container<T>> children();
+}
+
+interface Parent<T>
+{
+	public Children<T> children();
+}
+
+interface Children<T> extends Iterable<T>
+{
+	public int size();
+}
+
+interface Attribute
+{
+}
+
+interface Node extends Parent<Node>
+{
+	public Attribute get();
+}
+
+class Hoge<T extends Parent<T>>
+{
+	public static void main(String _args[])
+	{
+		
+	}
+	
+	
+	
+	public void visit(T _hoge)
+	{
+		Children<T> chs = _hoge.children();
+		for(T ch : chs){
+			visit(ch);
+		}
+	}
+}
+