Copyright (c) 2000, 2009 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.function.Function;

The SortOperation takes a collection of objects and returns
a sorted collection of these objects. The sorting of these
objects is based on their toString(). They are sorted in
alphabetical order.
/**
 * The SortOperation takes a collection of objects and returns
 * a sorted collection of these objects. The sorting of these
 * objects is based on their toString(). They are sorted in
 * alphabetical order.
 */
public class ToStringSorter <T> {
	private final Function<T, String> toString;

	public ToStringSorter(Function<T, String> toString) {
		this.toString = toString;
	}

	static class Pair<T> implements Comparable<Pair<T>> {
		final T object;
		final String string;
		public Pair(T k, String s) {
			this.object = k;
			this.string = s;
		}

		@Override
		public int compareTo(Pair<T> other) {
			return this.string.compareTo(other.string);
		}
	}

	
 Return a new sorted collection from this unsorted collection.
/**
	 *  Return a new sorted collection from this unsorted collection.
	 */
	public List<Pair<T>> sort(Collection<T> unSorted) {
		int size = unSorted.size();
		//copy the list so can return a new sorted collection
		List<Pair <T>> sortedObjects = new ArrayList<>(size);
		unSorted.forEach(k -> sortedObjects.add(new Pair<>(k, this.toString.apply(k))));
		Collections.sort(sortedObjects);
		return sortedObjects;
	}
}