Fixed loops in transitive closure

2 files changed, 6 insertions, 4 deletions

diff --git a/src/clojure/contrib/graph.clj b/src/clojure/contrib/graph.clj
index 5452340a..8e2eda16 100644
--- a/src/clojure/contrib/graph.clj
+++ b/src/clojure/contrib/graph.clj
@@ -69,7 +69,7 @@
   ([g n]
      (lazy-walk g [n] #{}))
   ([g ns v]
-     (lazy-seq (let [s (seq (remove v ns))
+     (lazy-seq (let [s (seq (drop-while v ns))
                      n (first s)
                      ns (rest s)]
                  (when s
@@ -78,7 +78,9 @@
 (defn transitive-closure
   "Returns the transitive closure of a graph.  The neighbors are lazily computed."
   [g]
-  (let [nbs (into {} (map (fn [n] [n (delay (lazy-walk g n))]) (:nodes g)))]
+  (let [nns (fn [n]
+              [n (delay (lazy-walk g (get-neighbors g n) #{}))])
+        nbs (into {} (map nns (:nodes g)))]
     (struct directed-graph
             (:nodes g)
             (fn [n] (force (nbs n))))))
diff --git a/src/clojure/contrib/test_contrib/test_graph.clj b/src/clojure/contrib/test_contrib/test_graph.clj
index 09b3cc93..425966bf 100644
--- a/src/clojure/contrib/test_contrib/test_graph.clj
+++ b/src/clojure/contrib/test_contrib/test_graph.clj
@@ -79,9 +79,9 @@
     (is (every? #(= #{:a :b :c :d :e} (set %))
                 (map (partial get-neighbors tc-1) (:nodes tc-1))))
     (is (= (get :a) #{:a :b :c :d :e}))
-    (is (= (get :h) #{:h}))
+    (is (= (get :h) #{}))
     (is (= (get :j) #{:i :j}))
-    (is (= (get :g) #{:a :b :c :d :e :f :g}))))
+    (is (= (get :g) #{:a :b :c :d :e :f}))))
 
 
 (deftest test-post-ordered-nodes