Initial data commit

Task/Doubly-linked-list-Element-insertion/Clojure/doubly-linked-list-element-insertion.clj

@@ -0,0 +1,24 @@
+(defrecord Node [prev next data])
+
+(defn new-node [prev next data]
+  (Node. (ref prev) (ref next) data))
+
+(defn new-list [head tail]
+  (List. (ref head) (ref tail)))
+
+(defn insert-between [node1 node2 new-node]
+  (dosync
+   (ref-set (:next node1) new-node)
+   (ref-set (:prev new-node) node1)
+   (ref-set (:next new-node) node2)
+   (ref-set (:prev node2) new-node)))
+
+(set! *print-level* 1)
+
+;; warning: depending on the value of *print-level*
+;;   this could cause a stack overflow when printing
+
+(let [h (new-node nil nil :A)
+      t (new-node nil nil :B)]
+  (insert-between h t (new-node nil nil :C))
+  (new-list h t))