001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.ml.linear.learner;
031
032import java.util.HashMap;
033import java.util.Map;
034
035/**
036 * 
037 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
038 * 
039 */
040public class LearningParameters extends HashMap<String, Object> {
041        protected class Placeholder {
042                public Placeholder(String name) {
043                        this.name = name;
044                }
045
046                public String name;
047        }
048
049        private static final long serialVersionUID = 8150107681506488394L;
050
051        Map<String, Object> defaults = new HashMap<String, Object>();
052
053        public LearningParameters() {
054        }
055
056        public LearningParameters(Map<String, Object> defaults) {
057                this.defaults.putAll(defaults);
058        }
059
060        @SuppressWarnings("unchecked")
061        public <T> T getTyped(String s) {
062                Object thisVal = this.get(s);
063                if (thisVal == null) {
064                        thisVal = defaults.get(s);
065                }
066                if (thisVal != null && thisVal instanceof Placeholder) {
067                        return getTyped(((Placeholder) thisVal).name);
068                }
069                return (T) thisVal;
070        }
071}