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Java example source code file (APersistentMap.java)

This example Java source code file (APersistentMap.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

afn, entry, ifn, ipersistentmap, ipersistentvector, iseq, iterable, iterator, keyseq, map, object, set, unsupportedoperationexception, util, valseq

The APersistentMap.java Java example source code

/**
 *   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.
 **/

package clojure.lang;

import java.io.Serializable;
import java.util.*;

public abstract class APersistentMap extends AFn implements IPersistentMap, Map, Iterable, Serializable, MapEquivalence, IHashEq {
int _hash = -1;
int _hasheq = -1;

public String toString(){
	return RT.printString(this);
}

public IPersistentCollection cons(Object o){
	if(o instanceof Map.Entry)
		{
		Map.Entry e = (Map.Entry) o;

		return assoc(e.getKey(), e.getValue());
		}
	else if(o instanceof IPersistentVector)
		{
		IPersistentVector v = (IPersistentVector) o;
		if(v.count() != 2)
			throw new IllegalArgumentException("Vector arg to map conj must be a pair");
		return assoc(v.nth(0), v.nth(1));
		}

	IPersistentMap ret = this;
	for(ISeq es = RT.seq(o); es != null; es = es.next())
		{
		Map.Entry e = (Map.Entry) es.first();
		ret = ret.assoc(e.getKey(), e.getValue());
		}
	return ret;
}

public boolean equals(Object obj){
	return mapEquals(this, obj);
}

static public boolean mapEquals(IPersistentMap m1, Object obj){
	if(m1 == obj) return true;
	if(!(obj instanceof Map))
		return false;
	Map m = (Map) obj;

	if(m.size() != m1.count())
		return false;

	for(ISeq s = m1.seq(); s != null; s = s.next())
		{
		Map.Entry e = (Map.Entry) s.first();
		boolean found = m.containsKey(e.getKey());

		if(!found || !Util.equals(e.getValue(), m.get(e.getKey())))
			return false;
		}

	return true;
}

public boolean equiv(Object obj){
	if(!(obj instanceof Map))
		return false;
	if(obj instanceof IPersistentMap && !(obj instanceof MapEquivalence))
		return false;
	
	Map m = (Map) obj;

	if(m.size() != size())
		return false;

	for(ISeq s = seq(); s != null; s = s.next())
		{
		Map.Entry e = (Map.Entry) s.first();
		boolean found = m.containsKey(e.getKey());

		if(!found || !Util.equiv(e.getValue(), m.get(e.getKey())))
			return false;
		}

	return true;
}
public int hashCode(){
	if(_hash == -1)
		{
		this._hash = mapHash(this);
		}
	return _hash;
}

static public int mapHash(IPersistentMap m){
	int hash = 0;
	for(ISeq s = m.seq(); s != null; s = s.next())
		{
		Map.Entry e = (Map.Entry) s.first();
		hash += (e.getKey() == null ? 0 : e.getKey().hashCode()) ^
				(e.getValue() == null ? 0 : e.getValue().hashCode());
		}
	return hash;
}

public int hasheq(){
	if(_hasheq == -1)
		{
		//this._hasheq = mapHasheq(this);
		_hasheq = Murmur3.hashUnordered(this);
		}
	return _hasheq;
}

static public int mapHasheq(IPersistentMap m) {
	return Murmur3.hashUnordered(m);
//	int hash = 0;
//	for(ISeq s = m.seq(); s != null; s = s.next())
//		{
//		Map.Entry e = (Map.Entry) s.first();
//		hash += Util.hasheq(e.getKey()) ^
//				Util.hasheq(e.getValue());
//		}
//	return hash;
}

static public class KeySeq extends ASeq{
	final ISeq seq;
	final Iterable iterable;

	static public KeySeq create(ISeq seq){
		if(seq == null)
			return null;
		return new KeySeq(seq, null);
	}

	static public KeySeq createFromMap(IPersistentMap map){
		if(map == null)
			return null;
		ISeq seq = map.seq();
		if(seq == null)
			return null;
		return new KeySeq(seq, map);
	}

	private KeySeq(ISeq seq, Iterable iterable){
		this.seq = seq;
		this.iterable = iterable;
	}

	private KeySeq(IPersistentMap meta, ISeq seq, Iterable iterable){
		super(meta);
		this.seq = seq;
		this.iterable = iterable;
	}

	public Object first(){
		return ((Map.Entry) seq.first()).getKey();
	}

	public ISeq next(){
		return create(seq.next());
	}

	public KeySeq withMeta(IPersistentMap meta){
		return new KeySeq(meta, seq, iterable);
	}

	public Iterator iterator(){
		if(iterable == null)
			return super.iterator();

		if(iterable instanceof IMapIterable)
			return ((IMapIterable)iterable).keyIterator();

		final Iterator mapIter = iterable.iterator();
		return new Iterator() {
			public boolean hasNext() {
				return mapIter.hasNext();
			}

			public Object next() {
				return ((Map.Entry)mapIter.next()).getKey();
			}

			public void remove() {
				throw new UnsupportedOperationException();
			}
		};
	}
}

static public class ValSeq extends ASeq{
	final ISeq seq;
	final Iterable iterable;

	static public ValSeq create(ISeq seq){
		if(seq == null)
			return null;
		return new ValSeq(seq, null);
	}

	static public ValSeq createFromMap(IPersistentMap map) {
		if(map == null)
			return null;
		ISeq seq = map.seq();
		if(seq == null)
			return null;
		return new ValSeq(seq, map);
	}

	private ValSeq(ISeq seq, Iterable iterable){
		this.seq = seq;
		this.iterable = iterable;
	}

	private ValSeq(IPersistentMap meta, ISeq seq, Iterable iterable){
		super(meta);
		this.seq = seq;
		this.iterable = iterable;
	}

	public Object first(){
		return ((Map.Entry) seq.first()).getValue();
	}

	public ISeq next(){
		return create(seq.next());
	}

	public ValSeq withMeta(IPersistentMap meta){
		return new ValSeq(meta, seq, iterable);
	}

	public Iterator iterator(){
		if(iterable == null)
			return super.iterator();

		if(iterable instanceof IMapIterable)
			return ((IMapIterable)iterable).valIterator();

		final Iterator mapIter = iterable.iterator();
		return new Iterator() {
			public boolean hasNext() {
				return mapIter.hasNext();
			}

			public Object next() {
				return ((Map.Entry)mapIter.next()).getValue();
			}

			public void remove() {
				throw new UnsupportedOperationException();
			}
		};
	}
}

static final IFn MAKE_ENTRY = new AFn() {
    public Object invoke(Object key, Object val) {
        return MapEntry.create(key, val);
    }
};

static final IFn MAKE_KEY = new AFn() {
    public Object invoke(Object key, Object val) {
        return key;
    }
};

static final IFn MAKE_VAL = new AFn() {
    public Object invoke(Object key, Object val) {
        return val;
    }
};

public Object invoke(Object arg1) {
	return valAt(arg1);
}

public Object invoke(Object arg1, Object notFound) {
	return valAt(arg1, notFound);
}

// java.util.Map implementation

public void clear(){
	throw new UnsupportedOperationException();
}

public boolean containsValue(Object value){
	return values().contains(value);
}

public Set entrySet(){
	return new AbstractSet(){

		public Iterator iterator(){
			return APersistentMap.this.iterator();
		}

		public int size(){
			return count();
		}

		public int hashCode(){
			return APersistentMap.this.hashCode();
		}

		public boolean contains(Object o){
			if(o instanceof Entry)
				{
				Entry e = (Entry) o;
				Entry found = entryAt(e.getKey());
				if(found != null && Util.equals(found.getValue(), e.getValue()))
					return true;
				}
			return false;
		}
	};
}

public Object get(Object key){
	return valAt(key);
}

public boolean isEmpty(){
	return count() == 0;
}

public Set keySet(){
	return new AbstractSet(){

		public Iterator iterator(){
			final Iterator mi = APersistentMap.this.iterator();

			return new Iterator(){


				public boolean hasNext(){
					return mi.hasNext();
				}

				public Object next(){
					Entry e = (Entry) mi.next();
					return e.getKey();
				}

				public void remove(){
					throw new UnsupportedOperationException();
				}
			};
		}

		public int size(){
			return count();
		}

		public boolean contains(Object o){
			return APersistentMap.this.containsKey(o);
		}
	};
}

public Object put(Object key, Object value){
	throw new UnsupportedOperationException();
}

public void putAll(Map t){
	throw new UnsupportedOperationException();
}

public Object remove(Object key){
	throw new UnsupportedOperationException();
}

public int size(){
	return count();
}

public Collection values(){
	return new AbstractCollection(){

		public Iterator iterator(){
			final Iterator mi = APersistentMap.this.iterator();

			return new Iterator(){


				public boolean hasNext(){
					return mi.hasNext();
				}

				public Object next(){
					Entry e = (Entry) mi.next();
					return e.getValue();
				}

				public void remove(){
					throw new UnsupportedOperationException();
				}
			};
		}

		public int size(){
			return count();
		}
	};
}

/*
// java.util.Collection implementation

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){
	if(a.length >= count())
		{
		ISeq s = seq();
		for(int i = 0; s != null; ++i, s = s.rest())
			{
			a[i] = s.first();
			}
		if(a.length > count())
			a[count()] = null;
		return a;
		}
	else
		return toArray();
}

public int size(){
	return count();
}

public boolean isEmpty(){
	return count() == 0;
}

public boolean contains(Object o){
	if(o instanceof Map.Entry)
		{
		Map.Entry e = (Map.Entry) o;
		Map.Entry v = entryAt(e.getKey());
		return (v != null && Util.equal(v.getValue(), e.getValue()));
		}
	return false;
}
*/
}

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