1 /*
   2  * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package java.util.function;
  26 
  27 /**
  28  * Apply a function to the input object yielding an appropriate result object. A
  29  * function may variously provide a mapping between types, object instances or
  30  * keys and values or any other form of transformation upon the input.
  31  *
  32  * @param <T> the type of input objects to the {@code apply} operation
  33  * @param <R> the type of result objects from the {@code apply} operation. May
  34  * be the same type as {@code <T>}.
  35  *
  36  * @since 1.8
  37  */
  38 public interface Function<T, R> {
  39 
  40     /**
  41      * Yield an appropriate result object for the input object.
  42      *
  43      * @param t the input object
  44      * @return the function result
  45      */
  46     public R apply(T t);
  47 }