| /* |
| * [The "BSD license"] |
| * Copyright (c) 2010 Terence Parr |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.antlr.misc; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| |
| /** A HashMap that remembers the order that the elements were added. |
| * You can alter the ith element with set(i,value) too :) Unique list. |
| * I need the replace/set-element-i functionality so I'm subclassing |
| * OrderedHashSet. |
| */ |
| public class OrderedHashSet<T> extends LinkedHashSet<T> { |
| /** Track the elements as they are added to the set */ |
| protected List<T> elements = new ArrayList<T>(); |
| |
| public T get(int i) { |
| return elements.get(i); |
| } |
| |
| /** Replace an existing value with a new value; updates the element |
| * list and the hash table, but not the key as that has not changed. |
| */ |
| public T set(int i, T value) { |
| T oldElement = elements.get(i); |
| elements.set(i,value); // update list |
| super.remove(oldElement); // now update the set: remove/add |
| super.add(value); |
| return oldElement; |
| } |
| |
| /** Add a value to list; keep in hashtable for consistency also; |
| * Key is object itself. Good for say asking if a certain string is in |
| * a list of strings. |
| */ |
| @Override |
| public boolean add(T value) { |
| boolean result = super.add(value); |
| if ( result ) { // only track if new element not in set |
| elements.add(value); |
| } |
| return result; |
| } |
| |
| @Override |
| public boolean remove(Object o) { |
| throw new UnsupportedOperationException(); |
| /* |
| elements.remove(o); |
| return super.remove(o); |
| */ |
| } |
| |
| @Override |
| public void clear() { |
| elements.clear(); |
| super.clear(); |
| } |
| |
| /** Return the List holding list of table elements. Note that you are |
| * NOT getting a copy so don't write to the list. |
| */ |
| public List<T> elements() { |
| return elements; |
| } |
| |
| @Override |
| public Iterator<T> iterator() { |
| return elements.iterator(); |
| } |
| |
| @Override |
| public Object[] toArray() { |
| return elements.toArray(); |
| } |
| |
| @Override |
| public int size() { |
| /* |
| if ( elements.size()!=super.size() ) { |
| ErrorManager.internalError("OrderedHashSet: elements and set size differs; "+ |
| elements.size()+"!="+super.size()); |
| } |
| */ |
| return elements.size(); |
| } |
| |
| @Override |
| public String toString() { |
| return elements.toString(); |
| } |
| } |