water.udf.fp

Interface Foldable<X,Y>

All Superinterfaces:

java.io.Serializable

public interface Foldable<X,Y>
extends java.io.Serializable

Represents a folding operation applicable to streams or collection Initial value of type Y is the value that is returned on an empty collection. Apply is used on a pair of values to produce the next value. Apply takes a value of argument type X and a value of result type Y. Having this, you can define reduction on a collection or a stream. This is the core of map/reduce.

See Also:

wikipedia for details.

Method Summary

Methods

Modifier and Type	Method and Description
Y	apply(Y y, X x)
Y	initial()

Method Detail

initial

Y initial()

apply

Y apply(Y y,
      X x)