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Diffstat (limited to 'gnu/java/security/util/SimpleList.java')
-rw-r--r-- | gnu/java/security/util/SimpleList.java | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/gnu/java/security/util/SimpleList.java b/gnu/java/security/util/SimpleList.java new file mode 100644 index 000000000..b2525c4b8 --- /dev/null +++ b/gnu/java/security/util/SimpleList.java @@ -0,0 +1,171 @@ +/* SimpleList.java -- simple way to make tuples. + Copyright (C) 2004, 2006 Free Software Foundation, Inc. + +This file is a part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at +your option) any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 +USA + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.java.security.util; + +import java.util.AbstractList; +import java.util.Collection; +import java.util.Iterator; + +/** + * A simple way to create immutable n-tuples. This class can be created with + * up to four elements specified via one of the constructors, or with a + * collection of arbitrary size. + */ +public final class SimpleList extends AbstractList +{ + + // Fields. + // ------------------------------------------------------------------------ + + private final Object[] elements; + + // Constructors. + // ------------------------------------------------------------------------ + + /** + * Create a singleton list. + * + * @param e1 The first element. + */ + public SimpleList(final Object element) + { + elements = new Object[1]; + elements[0] = element; + } + + /** + * Create an ordered pair (2-tuple). + * + * @param e1 The first element. + * @param e2 The second element. + */ + public SimpleList(final Object e1, final Object e2) + { + elements = new Object[2]; + elements[0] = e1; + elements[1] = e2; + } + + /** + * Create a 3-tuple. + * + * @param e1 The first element. + * @param e2 The second element. + * @param e3 The third element. + */ + public SimpleList(final Object e1, final Object e2, final Object e3) + { + elements = new Object[3]; + elements[0] = e1; + elements[1] = e2; + elements[2] = e3; + } + + /** + * Create a 4-tuple. + * + * @param e1 The first element. + * @param e2 The second element. + * @param e3 The third element. + * @param e4 The fourth element. + */ + public SimpleList(final Object e1, final Object e2, final Object e3, + final Object e4) + { + elements = new Object[4]; + elements[0] = e1; + elements[1] = e2; + elements[2] = e3; + elements[3] = e4; + } + + /** + * Create the empty list. + */ + public SimpleList() + { + elements = null; + } + + /** + * Create an n-tuple of arbitrary size. Even if the supplied collection has + * no natural order, the created n-tuple will have the order that the + * elements are returned by the collection's iterator. + * + * @param c The collection. + */ + public SimpleList(Collection c) + { + elements = new Object[c.size()]; + int i = 0; + for (Iterator it = c.iterator(); it.hasNext() && i < elements.length;) + { + elements[i++] = it.next(); + } + } + + // Instance methods. + // ------------------------------------------------------------------------ + + public int size() + { + if (elements == null) + return 0; + return elements.length; + } + + public Object get(int index) + { + if (elements == null) + { + throw new IndexOutOfBoundsException("list is empty"); + } + if (index < 0 || index >= elements.length) + { + throw new IndexOutOfBoundsException("index=" + index + ", size=" + + size()); + } + return elements[index]; + } + + public String toString() + { + return SimpleList.class.getName() + "(" + size() + ") " + super.toString(); + } +} |