--- a/src/luan/LuanClosure.java	Sun Jan 31 16:04:39 2021 -0700
+++ b/src/luan/LuanClosure.java	Mon Feb 08 14:16:19 2021 -0700
@@ -3,12 +3,11 @@
 import luan.impl.Pointer;
 
 
-public abstract class LuanClosure extends LuanFunction implements LuanCloneable, Cloneable {
+public abstract class LuanClosure extends LuanFunction implements LuanMutable {
 	public Pointer[] upValues;
 	public boolean javaOk;
 	public final String sourceName;
-	private LuanCloner cloner;
-	private Luan luan;
+	private boolean immutable = false;
 
 	public LuanClosure(Pointer[] upValues,boolean javaOk,String sourceName) throws LuanException {
 		this.upValues = upValues;
@@ -16,55 +15,18 @@
 		this.sourceName = sourceName;
 	}
 
-	@Override public final LuanClosure shallowClone() {
-		check();
-		try {
-			return (LuanClosure)clone();
-		} catch(CloneNotSupportedException e) {
-			throw new RuntimeException(e);
-		}
-	}
-
-	private void check() {
-		if( cloner != null ) {
-			completeClone(this,cloner);
-			cloner = null;
-		}
+	@Override public final boolean isImmutable() {
+		return immutable;
 	}
 
-	private void checkLuan(Luan luan) {
-		check();
-		if( this.luan==null ) {
-			this.luan = luan;
-		} else if( this.luan != luan ) {
-			throw new RuntimeException("wrong luan");
-		}
-	}
-
-	@Override public final void deepenClone(LuanCloneable dc,LuanCloner cloner) {
-		LuanClosure clone = (LuanClosure)dc;
-		switch( cloner.type ) {
-		case COMPLETE:
-			completeClone(clone,cloner);
+	@Override public final void makeImmutable() {
+		if(immutable)
 			return;
-		case INCREMENTAL:
-			clone.cloner = cloner;
-			return;
-		}
-	}
-
-	private void completeClone(LuanClosure dc,LuanCloner cloner) {
-		LuanClosure clone = (LuanClosure)dc;
-		clone.upValues = (Pointer[])cloner.clone(upValues);
-		clone.luan = (Luan)cloner.clone(luan);
-	}
-
-	@Override public final void makeImmutable(LuanImmutabler immutabler) throws LuanException {
-		immutabler.makeImmutable(upValues);
+		immutable = true;
+		LuanMutable.makeImmutable(upValues);
 	}
 
 	@Override public final Object call(Luan luan,Object... args) throws LuanException {
-		check();
 		luan.push(this);
 		try {
 			return doCall(luan,args);
@@ -75,7 +37,7 @@
 		}	
 	}
 
-	@Override public String toString() {
+	@Override public final String toString() {
 		return super.toString()+"="+sourceName;
 	}