001    /*
002     $Id: SpreadMap.java,v 1.2 2005/07/23 12:09:47 phk Exp $
003    
004     Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005    
006     Redistribution and use of this software and associated documentation
007     ("Software"), with or without modification, are permitted provided
008     that the following conditions are met:
009    
010     1. Redistributions of source code must retain copyright
011        statements and notices.  Redistributions must also contain a
012        copy of this document.
013    
014     2. Redistributions in binary form must reproduce the
015        above copyright notice, this list of conditions and the
016        following disclaimer in the documentation and/or other
017        materials provided with the distribution.
018    
019     3. The name "groovy" must not be used to endorse or promote
020        products derived from this Software without prior written
021        permission of The Codehaus.  For written permission,
022        please contact info@codehaus.org.
023    
024     4. Products derived from this Software may not be called "groovy"
025        nor may "groovy" appear in their names without prior written
026        permission of The Codehaus. "groovy" is a registered
027        trademark of The Codehaus.
028    
029     5. Due credit should be given to The Codehaus -
030        http://groovy.codehaus.org/
031    
032     THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033     ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034     NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035     FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
036     THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037     INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039     SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041     STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043     OF THE POSSIBILITY OF SUCH DAMAGE.
044    
045     */
046    package groovy.lang;
047    
048    import java.util.HashMap;
049    import java.util.Map;
050    import java.util.Iterator;
051    
052    import org.codehaus.groovy.runtime.InvokerHelper;
053    
054    /**
055     * Represents a spreadable map which extends java.util.HashMap.
056     * 
057     * @author Pilho Kim
058     * @version $Revision: 1.2 $
059     */
060    public class SpreadMap extends HashMap {
061    
062        private Map mapData;
063        private int hashCode;
064    
065        public SpreadMap(Object[] values) {
066            mapData = new HashMap(values.length / 2);
067            int i = 0;
068            while (i < values.length) {
069               mapData.put(values[i++], values[i++]);
070            }
071        }
072    
073        public SpreadMap(Map map) {
074            this.mapData = map;
075        }
076    
077        public Object get(Object obj) {
078            return mapData.get(obj);
079        }
080    
081        public Object put(Object key, Object value) {
082            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so ("
083                                       + key + ": " + value + ") cannot be added.");
084        }
085    
086        public Object remove(Object key) {
087            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the key ("
088                                       + key + ") cannot be deleteded.");
089        }
090    
091        public void putAll(Map t) {
092            throw new RuntimeException("SpreadMap: " + this + " is an immutable map, and so the map ("
093                                       + t + ") cannot be put in this spreadMap.");
094        }
095    
096        public int size() {
097            return mapData.keySet().size();
098        }
099    
100        public boolean equals(Object that) {
101            if (that instanceof SpreadMap) {
102                return equals((SpreadMap) that);
103            }
104            return false;
105        }
106    
107        public boolean equals(SpreadMap that) {
108            if (this == null && that == null)
109                return true;
110            else if (this != null && that == null)
111                return false;
112            else if (this == null && that != null)
113                return false;
114    
115            if (size() == that.size()) {
116                SpreadMap other = (SpreadMap) that;
117                Iterator iter = mapData.keySet().iterator();
118                for (; iter.hasNext(); ) {
119                    Object key = iter.next();
120                    if (! InvokerHelper.compareEqual(get(key), other.get(key)) ) {
121                        return false;
122                    }
123                }
124                return true;
125            }
126            return false;
127        }
128    
129    
130        public int hashCode() {
131            if (hashCode == 0) {
132                Iterator iter = mapData.keySet().iterator();
133                for (; iter.hasNext(); ) {
134                    Object key = iter.next();
135                    int hash = (key != null) ? key.hashCode() : 0xbabe;
136                    hashCode ^= hash;
137                }
138            }
139            return hashCode;
140        }
141    
142        /**
143         * Returns the string expression of <code>this</code>.
144         *
145         * @return the string expression of <code>this</code>
146         */
147        public String toString() {
148            if (mapData.isEmpty()) {
149                return "*:[:]";
150            }
151            StringBuffer buff = new StringBuffer("*:[");
152            Iterator iter = mapData.keySet().iterator();
153            for (; iter.hasNext(); ) {
154                Object key = iter.next();
155                buff.append(key + ":" + mapData.get(key));
156                if (iter.hasNext())
157                    buff.append(", ");
158            }
159            buff.append("]");
160            return buff.toString();
161        }
162    }