001package Torello.Java.Function;
002
003import java.util.function.Function;
004
005/**
006 * Function-Pointer
007 * <SPAN CLASS=TJF>Input:</SPAN> {@code int, long}
008 * <SPAN CLASS=TJF>Output:</SPAN> {@code R}.
009 * 
010 * <BR /><BR />
011 * <EMBED CLASS='external-html' DATA-FILE-ID=TWO_PRIMITIVE_FUNC>
012 * <EMBED CLASS="globalDefs" DATA-Type1=int DATA-Type2=long>
013 * 
014 * @param <R> The type of the function-output.
015 */
016@FunctionalInterface
017public interface IntLongFunction<R>
018{
019    /**
020     * Applies this function to the given arguments.
021     * <BR /><BR /><EMBED CLASS='external-html' DATA-FILE-ID=FUNC_INTER_METH>
022     *
023     * @param i The integer (first) argument to the function.
024     * @param l The long (second) argument to the function.
025     * @return The function result.  Result shall be of type {@code 'R'}
026     */
027    public R apply(int i, long l);
028
029    /**
030     * Returns a composed function that first applies {@code 'this'} function to its input, and
031     * then applies the {@code 'after'} function to the result. If evaluation of either function
032     * throws an exception, it is relayed to the caller of the composed function.
033     * 
034     * @param <V> The output-type of the {@code 'after'} function, and also of the (returned)
035     * {@code 'composed'} function.
036     * 
037     * @param after The function to apply, after this function is applied.
038     * @throws NullPointerException This throws if null is passed to {@code 'after'}.
039     */
040    public default <V> IntLongFunction<V> andThen(Function<R, V> after)
041    {
042        if (after == null) throw new NullPointerException
043            ("null has been passed to parameter 'after'");
044
045        return (int i, long l) -> after.apply(this.apply(i, l));
046    }
047}