1 files changed, 59 insertions, 0 deletions
diff --git a/plugins/infra/core/org.eclipse.papyrus.infra.tools/src/org/eclipse/papyrus/infra/tools/util/Iterators2.java b/plugins/infra/core/org.eclipse.papyrus.infra.tools/src/org/eclipse/papyrus/infra/tools/util/Iterators2.java
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index 00000000000..bd10ef4e9d7
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+++ b/plugins/infra/core/org.eclipse.papyrus.infra.tools/src/org/eclipse/papyrus/infra/tools/util/Iterators2.java
@@ -0,0 +1,59 @@
+/*****************************************************************************
+ * Copyright (c) 2014 Christian W. Damus and others.
+ * 
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Christian W. Damus - Initial API and implementation
+ *   
+ *****************************************************************************/
+
+package org.eclipse.papyrus.infra.tools.util;
+
+import java.util.Iterator;
+
+import org.eclipse.emf.common.util.TreeIterator;
+
+import com.google.common.collect.AbstractIterator;
+import com.google.common.collect.Iterators;
+
+/**
+ * Utilities for working with iterators that are not provided by {@linkplain Iterators Guava}.
+ */
+public class Iterators2 {
+	/**
+	 * Not instantiable by clients.
+	 */
+	private Iterators2() {
+		super();
+	}
+
+	/**
+	 * Filters an EMF tree iterator for elements of a particular {@code type}.
+	 * 
+	 * @param treeIterator
+	 *            the tree iterator to filter
+	 * @param type
+	 *            the type of elements to include in the filtered tree iterator
+	 * @return the filtered tree iterator
+	 */
+	public static <T> TreeIterator<T> filter(final TreeIterator<?> treeIterator, final Class<T> type) {
+		class FilteredTreeIterator extends AbstractIterator<T> implements TreeIterator<T> {
+			final Iterator<T> delegate = Iterators.filter(treeIterator, type);
+
+			@Override
+			protected T computeNext() {
+				return delegate.hasNext() ? delegate.next() : endOfData();
+			}
+
+			public void prune() {
+				treeIterator.prune();
+			}
+		}
+
+		return new FilteredTreeIterator();
+	}
+}