reversible support for Vec #267

Signed-off-by: Stuart Halloway <stu@thinkrelevance.com>

3 files changed, 29 insertions, 4 deletions

diff --git a/src/clj/clojure/gvec.clj b/src/clj/clojure/gvec.clj
index 6c025835..ff89aade 100644
--- a/src/clj/clojure/gvec.clj
+++ b/src/clj/clojure/gvec.clj
@@ -194,7 +194,7 @@
      (or (instance? clojure.lang.Sequential o) (instance? java.util.List o))
        (= (seq this) (seq o))
      :else false))
-  
+
   clojure.lang.IPersistentStack
   (peek [this]
     (when (> cnt (int 0)) 
@@ -233,7 +233,13 @@
          (new Vec am cnt shift (.doAssoc this shift root i val) tail (meta this)))
      (= i cnt) (.cons this val)
      :else (throw (IndexOutOfBoundsException.))))
-
+  
+  clojure.lang.Reversible
+  (rseq [this]
+        (if (> (.count this) 0)
+          (clojure.lang.APersistentVector$RSeq. this (dec (.count this)))
+          nil))
+  
   clojure.lang.Associative
   (assoc [this k v]
     (if (clojure.lang.Util/isInteger k)
diff --git a/src/jvm/clojure/lang/APersistentVector.java b/src/jvm/clojure/lang/APersistentVector.java
index 7ac9f32b..a6b7405f 100644
--- a/src/jvm/clojure/lang/APersistentVector.java
+++ b/src/jvm/clojure/lang/APersistentVector.java
@@ -458,11 +458,11 @@ public int compareTo(Object o){
 	}
     }
 
-static class RSeq extends ASeq implements IndexedSeq, Counted{
+public static class RSeq extends ASeq implements IndexedSeq, Counted{
 	final IPersistentVector v;
 	final int i;
 
-	RSeq(IPersistentVector vector, int i){
+	public RSeq(IPersistentVector vector, int i){
 		this.v = vector;
 		this.i = i;
 	}
diff --git a/test/clojure/test_clojure/vectors.clj b/test/clojure/test_clojure/vectors.clj
index 654a5b84..35341e85 100644
--- a/test/clojure/test_clojure/vectors.clj
+++ b/test/clojure/test_clojure/vectors.clj
@@ -11,6 +11,25 @@
 (ns clojure.test-clojure.vectors
   (:use clojure.test))
 
+(deftest test-reversed-vec
+  (let [r (range 6)
+        v (into (vector-of :int) r)
+        reversed (.rseq v)]
+    (testing "returns the right impl"
+      (is (= clojure.lang.APersistentVector$RSeq (class reversed))))
+    (testing "RSeq methods"
+      (is (= [5 4 3 2 1 0] reversed))
+      (is (= 5 (.index reversed)))
+      (is (= 5 (.first reversed)))
+      (is (= [4 3 2 1 0] (.next reversed)))
+      (is (= [3 2 1 0] (.. reversed next next)))
+      (is (= 6 (.count reversed))))
+    (testing "clojure calling through"
+      (is (= 5 (first reversed)))
+      (is (= 5 (nth reversed 0))))
+    (testing "empty reverses to nil"
+      (is (nil? (.. v empty rseq))))))
+
 (deftest test-vecseq
   (let [r (range 100)
         vs (into (vector-of :int) r)