Map/Reduce with Groovy++

gistfile1.txt

        ForkJoinPool fjPool = []
        def res = fjPool.map(2..<15){ arg ->
            // We are in AsyncTaskWithArg<Integer,Integer>
            // function which take Integer param and calculate Integer
            // both types are type inferenced
            //
            // method map will fork copy of the task for each element of given Iterable ( 2..<15 Range in this case)
            // and when all results ready will merge them in to List<Integer>
            
            // The task itself (the one applied to each element) uses fork/join (which is stupid for Fibonacci)

            // For small numbers we just set resut
            if(arg <= 1 ) {
                // set result of subtask and return null (no merge needed)
                return complete(1)
            }

            // clone two copies of itself and start running concurrently with new arguments 
            def f1 = fork(arg-1)
            def f2 = fork(arg-2)

            // what we return is merge function to be called when all subtasks are completed
            return {
                Integer r1 = f1.join(),
                        r2 = f2.join()
                r1 + r2
            }
        }
        assert res == [2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]