001/*-------------------------------------------------------------------------+
002|                                                                          |
003| Copyright 2005-2011 The ConQAT Project                                   |
004|                                                                          |
005| Licensed under the Apache License, Version 2.0 (the "License");          |
006| you may not use this file except in compliance with the License.         |
007| You may obtain a copy of the License at                                  |
008|                                                                          |
009|    http://www.apache.org/licenses/LICENSE-2.0                            |
010|                                                                          |
011| Unless required by applicable law or agreed to in writing, software      |
012| distributed under the License is distributed on an "AS IS" BASIS,        |
013| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
014| See the License for the specific language governing permissions and      |
015| limitations under the License.                                           |
016+-------------------------------------------------------------------------*/
017package org.conqat.lib.commons.collections;
018
019/**
020 * Abstraction for sortable/comparable data. Implementations of this interface
021 * can be used with {@link SortableDataUtils} to supports basic algorithms, such
022 * as sorting and binary search on any data which can be mapped to a random
023 * access list. The main benefit of this interface is that the type of data is
024 * operated on must not be known (or be a concrete type), thus it can also be
025 * used to sort data spread over multiple lists or arrays.
026 * 
027 * @author hummelb
028 */
029public interface ISortableData {
030
031        /** Returns the number of elements. */
032        int size();
033
034        /**
035         * Returns whether the element stored at index <code>i</code> is smaller
036         * than the one stored at <code>j</code>.
037         */
038        boolean isLess(int i, int j);
039
040        /** Swaps the elements at the given indices. */
041        void swap(int i, int j);
042}