Fold

Sometimes you just want to perform a simple operation across the values of a sequence. Fold is a good choice when you can use it, as it is fast and easy to use.

case class Fold[V](seed: V, f: (V, V) => V)

Just send a Fold message to a sequence and it returns a result of type V. It calls f(seed, value) on the each value in the sequence to calculate a revised seed--which at the end is the returned result. Testing this is a one liner.

println(Future(new Range(1,4), Fold(0, (a: Int, b: Int) => a + b)))

Output.

6

FoldTest

Tutorial