/**

* Copyright (c) Rich Hickey. All rights reserved.

* The use and distribution terms for this software are covered by the

* Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)

* which can be found in the file epl-v10.html at the root of this distribution.

* By using this software in any fashion, you are agreeing to be bound by

* the terms of this license.

* You must not remove this notice, or any other, from this software.

**/

/* rich Mar 3, 2008 */

package clojure.lang;

import java.io.Serializable;

import java.util.Collection;

import java.util.Iterator;

import java.util.Set;

public abstract class APersistentSet extends AFn implements IPersistentSet, Collection, Set, Serializable, IHashEq {

private static final long serialVersionUID = 889908853183699706L;

int _hash;

int _hasheq;

final IPersistentMap impl;

protected APersistentSet(IPersistentMap impl){

this.impl = impl;

}

public String toString(){

return RT.printString(this);

}

public boolean contains(Object key){

return impl.containsKey(key);

}

public Object get(Object key){

return impl.valAt(key);

}

public int count(){

return impl.count();

}

public ISeq seq(){

return RT.keys(impl);

}

public Object invoke(Object arg1) {

return get(arg1);

}

public boolean equals(Object obj){

return setEquals(this, obj);

}

static public boolean setEquals(IPersistentSet s1, Object obj) {

if(s1 == obj) return true;

if(!(obj instanceof Set))

return false;

Set m = (Set) obj;

if(m.size() != s1.count())

return false;

for(Object aM : m)

{

if(!s1.contains(aM))

return false;

}

return true;

}

public boolean equiv(Object obj){

if (!(obj instanceof Set))

return false;

Set m = (Set) obj;

if (m.size() != size())

return false;

for(Object aM : m)

{

if(!contains(aM))

return false;

}

return true;

}

public int hashCode(){

int hash = this._hash;

if(hash == 0)

{

//int hash = count();

for(ISeq s = seq(); s != null; s = s.next())

{

Object e = s.first();

// hash = Util.hashCombine(hash, Util.hash(e));

hash += Util.hash(e);

}

this._hash = hash;

}

return hash;

}

public int hasheq(){

int cached = this._hasheq;

if(cached == 0){

// int hash = 0;

// for(ISeq s = seq(); s != null; s = s.next())

// {

// Object e = s.first();

// hash += Util.hasheq(e);

// }

// this._hasheq = hash;

this._hasheq = cached = Murmur3.hashUnordered(this);

}

return cached;

}

public Object[] toArray(){

return RT.seqToArray(seq());

}

public boolean add(Object o){

throw new UnsupportedOperationException();

}

public boolean remove(Object o){

throw new UnsupportedOperationException();

}

public boolean addAll(Collection c){

throw new UnsupportedOperationException();

}

public void clear(){

throw new UnsupportedOperationException();

}

public boolean retainAll(Collection c){

throw new UnsupportedOperationException();

}

public boolean removeAll(Collection c){

throw new UnsupportedOperationException();

}

public boolean containsAll(Collection c){

for(Object o : c)

{

if(!contains(o))

return false;

}

return true;

}

public Object[] toArray(Object[] a){

return RT.seqToPassedArray(seq(), a);

}

public int size(){

return count();

}

public boolean isEmpty(){

return count() == 0;

}

public Iterator iterator(){

if(impl instanceof IMapIterable)

return ((IMapIterable)impl).keyIterator();

else return new Iterator() {

private final Iterator iter = impl.iterator();

public boolean hasNext() {

return iter.hasNext();

}

public Object next() {

return ((IMapEntry)iter.next()).key();

}

public void remove() {

throw new UnsupportedOperationException();

}

};

}

}