/*
* Copyright 2015 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package java.util.function;
import static javaemul.internal.InternalPreconditions.checkCriticalNotNull;
/**
* See <a href="https://docs.oracle.com/javase/8/docs/api/java/util/function/Function.html">
* the official Java API doc</a> for details.
*
* @param <T> type of the argument
* @param <R> type of the return value
*/
@FunctionalInterface
public interface Function<T, R> {
static <T> Function<T, T> identity() {
return t -> t;
}
R apply(T t);
default <V> Function<T, V> andThen(Function<? super R, ? extends V> after) {
checkCriticalNotNull(after);
return t -> after.apply(apply(t));
}
default <V> Function<V, R> compose(Function<? super V, ? extends T> before) {
checkCriticalNotNull(before);
return t -> apply(before.apply(t));
}
}