added overloads for Atom.swap

fix RT.nth for Lists to use count only for RandomAccess

3 files changed, 52 insertions, 4 deletions

diff --git a/src/clj/clojure/core.clj b/src/clj/clojure/core.clj
index d21c3f02..1b0d1484 100644
--- a/src/clj/clojure/core.clj
+++ b/src/clj/clojure/core.clj
@@ -1197,7 +1197,10 @@
   (apply f current-value-of-atom args). Note that f may be called
   multiple times, and thus should be free of side effects.  Returns
   the value that was swapped in."  
-  [#^clojure.lang.Atom atom f & args] (.swap atom f args))
+  ([#^clojure.lang.Atom atom f] (.swap atom f))
+  ([#^clojure.lang.Atom atom f x] (.swap atom f x))
+  ([#^clojure.lang.Atom atom f x y] (.swap atom f x y))
+  ([#^clojure.lang.Atom atom f x y & args] (.swap atom f x y args)))
 
 (defn compare-and-set! 
   "Atomically sets the value of atom to newval if and only if the
diff --git a/src/jvm/clojure/lang/Atom.java b/src/jvm/clojure/lang/Atom.java
index eb904c8f..3d02f6e4 100644
--- a/src/jvm/clojure/lang/Atom.java
+++ b/src/jvm/clojure/lang/Atom.java
@@ -30,11 +30,56 @@ public class Atom extends ARef{
         return state.get();
     }
 
-    public Object swap(IFn f, ISeq args) throws Exception {
+    public Object swap(IFn f) throws Exception {
         for(;;)
             {
             Object v = get();
-            Object newv = f.applyTo(new Cons(v, args));
+            Object newv = f.invoke(v);
+            validate(newv);
+            if(state.compareAndSet(v,newv))
+                {
+                if(v != newv)
+                    notifyWatches();
+                return newv;
+                }
+            }
+    }
+
+    public Object swap(IFn f, Object arg) throws Exception {
+        for(;;)
+            {
+            Object v = get();
+            Object newv = f.invoke(v,arg);
+            validate(newv);
+            if(state.compareAndSet(v,newv))
+                {
+                if(v != newv)
+                    notifyWatches();
+                return newv;
+                }
+            }
+    }
+
+    public Object swap(IFn f, Object arg1, Object arg2) throws Exception {
+        for(;;)
+            {
+            Object v = get();
+            Object newv = f.invoke(v, arg1, arg2);
+            validate(newv);
+            if(state.compareAndSet(v,newv))
+                {
+                if(v != newv)
+                    notifyWatches();
+                return newv;
+                }
+            }
+    }
+
+    public Object swap(IFn f, Object x, Object y, ISeq args) throws Exception {
+        for(;;)
+            {
+            Object v = get();
+            Object newv = f.applyTo(RT.listStar(v, x, y, args));
             validate(newv);
             if(state.compareAndSet(v,newv))
                 {
diff --git a/src/jvm/clojure/lang/RT.java b/src/jvm/clojure/lang/RT.java
index f5d97e83..a277f89e 100644
--- a/src/jvm/clojure/lang/RT.java
+++ b/src/jvm/clojure/lang/RT.java
@@ -760,7 +760,7 @@ static public Object nth(Object coll, int n, Object notFound){
 			return Reflector.prepRet(Array.get(coll, n));
 		return notFound;
 		}
-	else if(coll instanceof List)
+	else if(coll instanceof RandomAccess)
 		{
 		List list = (List) coll;
 		if(n < list.size())