The abstract base class for Map functions. Map functions take elements and transform them, element wise. A Map function always produces a single result element for each input element. Typical applications are parsing elements, converting data types, or projecting out fields. Operations that produce multiple result elements from a single input element can be implemented using the {@link FlatMapFunction}.
The basic syntax for using a MapFunction is as follows:
DataSet input = ...; DataSet result = input.map(new MyMapFunction());
Like all functions, the MapFunction needs to be serializable, as defined in {@link java.io.Serializable}.
@param < IN> Type of the input elements.
@param < OUT> Type of the returned elements.