Class PersistentArrayMap

src/jvm/clojure/lang/PersistentArrayMap.java:30–562

Simple implementation of persistent map on an array Note that instances of this class are constant values i.e. add/remove etc return new values Copies array on every change, so only appropriate for _very_small_ maps null keys and values are ok, but you won't be able to dis

 */

public class PersistentArrayMap extends APersistentMap implements IObj, IEditableCollection, IMapIterable, IKVReduce, IDrop{

private static final long serialVersionUID = -2074065891090893601L;

final Object[] array;
static final int HASHTABLE_THRESHOLD = 16;

public static final PersistentArrayMap EMPTY = new PersistentArrayMap();
private final IPersistentMap _meta;

static public IPersistentMap create(Map other){
	ITransientMap ret = EMPTY.asTransient();
	for(Object o : other.entrySet())
		{
            Map.Entry e = (Entry) o;
            ret = ret.assoc(e.getKey(), e.getValue());
		}
	return ret.persistent();
}

protected PersistentArrayMap(){
	this.array = new Object[]{};
	this._meta = null;
}

public PersistentArrayMap withMeta(IPersistentMap meta){
	if(meta() == meta)
		return this;
	return new PersistentArrayMap(meta, array);
}

PersistentArrayMap create(Object... init){
	return new PersistentArrayMap(meta(), init);
}

IPersistentMap createHT(Object[] init){
	return PersistentHashMap.create(meta(), init);
}

static public PersistentArrayMap createWithCheck(Object[] init){
	for(int i=0;i< init.length;i += 2)
		{
		for(int j=i+2;j<init.length;j += 2)
			{
			if(equalKey(init[i],init[j]))
				throw new IllegalArgumentException("Duplicate key: " + init[i]);
			}
		}
	return new PersistentArrayMap(init);
}

/**
 * <p>This method attempts to find resue the given array as the basis for an array map as quickly as possible.</p>
 *
 * <p>If a trailing element exists in the array or it contains duplicate keys then it delegates to the complex path.</p>
 **/
static public PersistentArrayMap createAsIfByAssoc(Object[] init){
	boolean complexPath, hasTrailing;