001/* Copyright (C) 2013 TU Dortmund
002 * This file is part of AutomataLib, http://www.automatalib.net/.
003 * 
004 * AutomataLib is free software; you can redistribute it and/or
005 * modify it under the terms of the GNU Lesser General Public
006 * License version 3.0 as published by the Free Software Foundation.
007 * 
008 * AutomataLib is distributed in the hope that it will be useful,
009 * but WITHOUT ANY WARRANTY; without even the implied warranty of
010 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
011 * Lesser General Public License for more details.
012 * 
013 * You should have received a copy of the GNU Lesser General Public
014 * License along with AutomataLib; if not, see
015 * http://www.gnu.de/documents/lgpl.en.html.
016 */
017package net.automatalib.commons.util.mappings;
018
019import java.util.Map;
020
021/**
022 * An interface for mapping objects of a certain domain type
023 * to objects of a certain range type.
024 * <p>
025 * A mapping is very much like a {@link Map}, but the perspective is a
026 * different one: Whereas a map is a (particularly finite) key/value collection, a
027 * mapping is more like a function: it does not support retrieval of all keys or values,
028 * because it does not requires them to be stored at all. Instead, they can be calculated
029 * on the fly upon an invocation of {@link #get(Object)}.
030 * 
031 * @author Malte Isberner <malte.isberner@gmail.com>
032 *
033 * @param <D> domain type.
034 * @param <R> range type.
035 */
036public interface Mapping<D,R> {
037        /**
038         * Get the range object <code>elem</code> maps to.
039         * 
040         * @param elem object from the domain.
041         * @return the object from the range corresponding to
042         * <code>elem</code>.
043         */
044        public R get(D elem);
045}