001: /*
002: * Primitive Collections for Java.
003: * Copyright (C) 2002, 2003 Søren Bak
004: *
005: * This library is free software; you can redistribute it and/or
006: * modify it under the terms of the GNU Lesser General Public
007: * License as published by the Free Software Foundation; either
008: * version 2.1 of the License, or (at your option) any later version.
009: *
010: * This library is distributed in the hope that it will be useful,
011: * but WITHOUT ANY WARRANTY; without even the implied warranty of
012: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
013: * Lesser General Public License for more details.
014: *
015: * You should have received a copy of the GNU Lesser General Public
016: * License along with this library; if not, write to the Free Software
017: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
018: */
019: package bak.pcj.adapter;
020:
021: import bak.pcj.ShortIterator;
022: import bak.pcj.util.Exceptions;
023: import java.util.Iterator;
024:
025: /**
026: * This class represents adaptions of Java Collections Framework
027: * iterators to primitive iterators over short values.
028: *
029: * <p>
030: * Adapters from JCF collections to primitive collections will
031: * fail if the JCF collection contains <tt>null</tt> values or
032: * values of the wrong class. However, adapters are not fast
033: * failing in the case that the underlying collection should
034: * contain illegal values. To implement fast failure would require
035: * every operation to check every element of the underlying
036: * collection before doing anything. Instead validation methods
037: * are provided. They can be called using the assertion facility
038: * in the client code:
039: * <pre>
040: * CollectionToShortCollectionAdapter s;
041: * ...
042: * <b>assert</b> s.validate();
043: * </pre>
044: * or by letting the adapter throw an exception on illegal values:
045: * <pre>
046: * CollectionToShortCollectionAdapter s;
047: * ...
048: * s.evalidate(); // Throws an exception on illegal values
049: * </pre>
050: * Either way, validation must be invoked directly by the client
051: * code.
052: *
053: * @author Søren Bak
054: * @version 1.2 20-08-2003 23:18
055: * @since 1.0
056: */
057: public class IteratorToShortIteratorAdapter implements ShortIterator {
058:
059: /** The underlying iterator. */
060: private Iterator iterator;
061:
062: /**
063: * Creates a new adaption to an iterator over short
064: * values.
065: *
066: * @param iterator
067: * the underlying iterator. This iterator must
068: * return values of class
069: * {@link Short Short}. Otherwise a
070: * {@link ClassCastException ClassCastException}
071: * will be thrown by
072: * {@link #next() next()}.
073: *
074: * @throws NullPointerException
075: * if <tt>iterator</tt> is <tt>null</tt>.
076: */
077: public IteratorToShortIteratorAdapter(Iterator iterator) {
078: if (iterator == null)
079: Exceptions.nullArgument("iterator");
080: this .iterator = iterator;
081: }
082:
083: public boolean hasNext() {
084: return iterator.hasNext();
085: }
086:
087: /**
088: * @throws ClassCastException
089: * if the underlying iterator returns an object
090: * that is not of class
091: * {@link Short Short}.
092: */
093: public short next() {
094: return ((Short) iterator.next()).shortValue();
095: }
096:
097: public void remove() {
098: iterator.remove();
099: }
100:
101: }
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