# ThrowingFunction.java

    package org.codefilarete.tool.function;

    import java.util.Objects;
    import java.util.function.Function;

    /**
     * @author Guillaume Mary
     */
    @FunctionalInterface
    public interface ThrowingFunction<T, R, E extends Throwable> {

    	/**
    	 * Applies this function to the given argument.
    	 *
    	 * @param t the function argument
    	 * @return the function result
    	 */
    	R apply(T t) throws E;

    	default <RR> ThrowingFunction<T, RR, E> andThen(Function<? super R, ? extends RR> after) {
    		Objects.requireNonNull(after);
    		return (T t) -> after.apply(apply(t));
    	}

    	default <RR> ThrowingFunction<T, RR, E> andThen(ThrowingFunction<? super R, ? extends RR, E> after) {
    		Objects.requireNonNull(after);
    		return (T t) -> after.apply(apply(t));
    	}
    }