001// Copyright 2010, 2011 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry5.func; 016 017/** 018 * Interface for operation {@link Flow#map(Mapper)} to define how Flow elements are mapped from one type 019 * to another (or otherwise transformed). 020 * <p> 021 * This changed in 5.3 from an abstract base class to an interface. 022 * 023 * @since 5.2.0 024 * @param <S> 025 * type of source flow 026 * @param <T> 027 * type of target (output) flow 028 */ 029public interface Mapper<S, T> 030{ 031 /** 032 * Implemented in subclasses to map an element from the source flow to an element of the target 033 * flow. 034 */ 035 T map(S element); 036}