/* Alloy Analyzer 4 -- Copyright (c) 2006-2009, Felix Chang
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package edu.mit.csail.sdg.alloy4;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Collection;
import java.util.List;
import java.util.ArrayList;
import java.util.RandomAccess;
/** Immutable; implements a list based on equals(); null values are allowed.
*
* @param <T> - the type of element
*/
public final class ConstList<T> extends AbstractList<T> implements Serializable, RandomAccess {
/** Mutable; this implements a modifiable list that can be used to construct a ConstList; null values are allowed.
*
* @param <T> - the type of element
*/
public static final class TempList<T> {
/** The underlying list. */
private final ArrayList<T> list;
/** Nonnull iff this list is no longer modifiable. */
private ConstList<T> clist;
/** Construct an empty TempList. */
public TempList() { list = new ArrayList<T>(); }
/** Construct an empty TempList with initial capacity of n (if n<=0, the list will be given a default capacity of 0) */
public TempList(int n) { list = new ArrayList<T>(n>=0 ? n : 0); }
/** Construct a new TempList whose initial content is n references to the given elem (if n<=0, the created list is empty) */
public TempList(int n, T elem) { list = new ArrayList<T>(n>0 ? n : 0); while(n>0) { list.add(elem); n--; } }
/** Construct a new TempList whose initial content is equal to the given collection. */
public TempList(Collection<? extends T> all) { list = new ArrayList<T>(all); }
/** Construct a new TempList whose initial content is equal to the given array. */
public TempList(T... all) { list = new ArrayList<T>(all.length); for(int i=0; i<all.length; i++) list.add(all[i]); }
/** Returns a String representation. */
@Override public String toString() { return list.toString(); }
/** Throws an exception if the list is now unmodifiable. */
private void chk() { if (clist!=null) throw new UnsupportedOperationException(); }
/** Returns the size of the list. */
public int size() { return list.size(); }
/** Returns true if the element is in the list. */
public boolean contains(T elem) { return list.contains(elem); }
/** Returns the i-th element. */
public T get(int index) { return list.get(index); }
/** Removes then returns the i-th element. */
public T remove(int index) { chk(); return list.remove(index); }
/** Removes every element, then return itself. */
public TempList<T> clear() { chk(); list.clear(); return this; }
/** Appends the given element to the list, then return itself. */
public TempList<T> add(T elem) { chk(); list.add(elem); return this; }
/** Appends the elements in the given collection to the list, then return itself. */
public TempList<T> addAll(Iterable<? extends T> all) {
chk();
if (all instanceof Collection) list.addAll((Collection<? extends T>)all); else if (all!=null) { for(T x: all) list.add(x); }
return this;
}
/** Changes the i-th element to be the given element, then return itself. */
public TempList<T> set(int index, T elem) { chk(); list.set(index, elem); return this; }
/** Makes this TempList unmodifiable, then construct a ConstList backed by this TempList. */
@SuppressWarnings("unchecked")
public ConstList<T> makeConst() { if (clist==null) clist=(list.isEmpty() ? emptylist : new ConstList<T>(list)); return clist; }
}
/** This ensures this class can be serialized reliably. */
private static final long serialVersionUID = 0;
/** The underlying unmodifiable list. */
private final List<T> list;
/** This caches an unmodifiable empty list. */
@SuppressWarnings("unchecked")
private static final ConstList emptylist = new ConstList(new ArrayList<Object>(0));
/** Construct a ConstList with the given list as its backing store. */
private ConstList(List<T> list) {
this.list = list;
}
/** Return an unmodifiable empty list. */
@SuppressWarnings("unchecked")
public static<T> ConstList<T> make() {
return (ConstList<T>) emptylist;
}
/** Return an unmodifiable list consisting of "n" references to "elem".
* (If n<=0, we'll return an unmodifiable empty list)
*/
public static<T> ConstList<T> make(int n, T elem) {
if (n <= 0) return make();
ArrayList<T> ans = new ArrayList<T>(n);
while(n > 0) { ans.add(elem); n--; }
return new ConstList<T>(ans);
}
/** Return an unmodifiable list with the same elements as the given collection.
* (If collection==null, we'll return an unmodifiable empty list)
*/
public static<T> ConstList<T> make(Iterable<T> collection) {
if (collection == null) return make();
if (collection instanceof ConstList) return (ConstList<T>) collection;
if (collection instanceof Collection) {
Collection<T> col = (Collection<T>)collection;
if (col.isEmpty()) return make(); else return new ConstList<T>(new ArrayList<T>(col));
}
ArrayList<T> ans = null;
for(T x: collection) {
if (ans == null) ans = new ArrayList<T>();
ans.add(x);
}
if (ans==null) return make(); else return new ConstList<T>(ans);
}
/** Returns the i-th element
* @throws ArrayIndexOutOfBoundsException if the given index doesn't exist
*/
@Override public T get(int index) { return list.get(index); }
/** Returns the number of elements in this list. */
@Override public int size() { return list.size(); }
}