rlm@10: /**
rlm@10:  *   Copyright (c) Rich Hickey. All rights reserved.
rlm@10:  *   The use and distribution terms for this software are covered by the
rlm@10:  *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
rlm@10:  *   which can be found in the file epl-v10.html at the root of this distribution.
rlm@10:  *   By using this software in any fashion, you are agreeing to be bound by
rlm@10:  * 	 the terms of this license.
rlm@10:  *   You must not remove this notice, or any other, from this software.
rlm@10:  **/
rlm@10: 
rlm@10: /* rich Apr 19, 2008 */
rlm@10: 
rlm@10: package clojure.lang;
rlm@10: 
rlm@10: import java.math.BigInteger;
rlm@10: import java.util.Map;
rlm@10: import java.util.concurrent.ConcurrentHashMap;
rlm@10: import java.lang.ref.SoftReference;
rlm@10: import java.lang.ref.ReferenceQueue;
rlm@10: import java.lang.ref.Reference;
rlm@10: 
rlm@10: public class Util{
rlm@10: static public boolean equiv(Object k1, Object k2){
rlm@10: 	if(k1 == k2)
rlm@10: 		return true;
rlm@10: 	if(k1 != null)
rlm@10: 		{
rlm@10: 		if(k1 instanceof Number && k2 instanceof Number)
rlm@10: 			return Numbers.equiv(k1, k2);
rlm@10: 		else if(k1 instanceof IPersistentCollection || k2 instanceof IPersistentCollection)
rlm@10: 			return pcequiv(k1,k2);
rlm@10: 		return k1.equals(k2);
rlm@10: 		}
rlm@10: 	return false;
rlm@10: }
rlm@10: 
rlm@10: static public boolean pcequiv(Object k1, Object k2){
rlm@10: 	if(k1 instanceof IPersistentCollection)
rlm@10: 		return ((IPersistentCollection)k1).equiv(k2);
rlm@10: 	return ((IPersistentCollection)k2).equiv(k1);
rlm@10: }
rlm@10: 
rlm@10: static public boolean equals(Object k1, Object k2){
rlm@10: 	if(k1 == k2)
rlm@10: 		return true;
rlm@10: 	return k1 != null && k1.equals(k2);
rlm@10: }
rlm@10: 
rlm@10: static public boolean identical(Object k1, Object k2){
rlm@10: 	return k1 == k2;
rlm@10: }
rlm@10: 
rlm@10: static public Class classOf(Object x){
rlm@10: 	if(x != null)
rlm@10: 		return x.getClass();
rlm@10: 	return null;
rlm@10: }
rlm@10: 
rlm@10: static public int compare(Object k1, Object k2){
rlm@10: 	if(k1 == k2)
rlm@10: 		return 0;
rlm@10: 	if(k1 != null)
rlm@10: 		{
rlm@10: 		if(k2 == null)
rlm@10: 			return 1;
rlm@10: 		if(k1 instanceof Number)
rlm@10: 			return Numbers.compare((Number) k1, (Number) k2);
rlm@10: 		return ((Comparable) k1).compareTo(k2);
rlm@10: 		}
rlm@10: 	return -1;
rlm@10: }
rlm@10: 
rlm@10: static public int hash(Object o){
rlm@10: 	if(o == null)
rlm@10: 		return 0;
rlm@10: 	return o.hashCode();
rlm@10: }
rlm@10: 
rlm@10: static public int hashCombine(int seed, int hash){
rlm@10: 	//a la boost
rlm@10: 	seed ^= hash + 0x9e3779b9 + (seed << 6) + (seed >> 2);
rlm@10: 	return seed;
rlm@10: }
rlm@10: 
rlm@10: static public boolean isPrimitive(Class c){
rlm@10: 	return c != null && c.isPrimitive() && !(c == Void.TYPE);
rlm@10: }
rlm@10: 
rlm@10: static public boolean isInteger(Object x){
rlm@10: 	return x instanceof Integer
rlm@10: 			|| x instanceof Long
rlm@10: 			|| x instanceof BigInteger;
rlm@10: }
rlm@10: 
rlm@10: static public Object ret1(Object ret, Object nil){
rlm@10: 		return ret;
rlm@10: }
rlm@10: 
rlm@10: static public ISeq ret1(ISeq ret, Object nil){
rlm@10: 		return ret;
rlm@10: }
rlm@10: 
rlm@10: static public <K,V> void clearCache(ReferenceQueue rq, ConcurrentHashMap<K, SoftReference<V>> cache){
rlm@10: 		//cleanup any dead entries
rlm@10: 	if(rq.poll() != null)
rlm@10: 		{
rlm@10: 		while(rq.poll() != null)
rlm@10: 			;
rlm@10: 		for(Map.Entry<K, SoftReference<V>> e : cache.entrySet())
rlm@10: 			{
rlm@10: 			if(e.getValue().get() == null)
rlm@10: 				cache.remove(e.getKey(), e.getValue());
rlm@10: 			}
rlm@10: 		}
rlm@10: }
rlm@10: }