tapestry-func/src/main/java/org/apache/tapestry5/func/Mapper.java

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
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//
// http://www.apache.org/licenses/LICENSE-2.0
//
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package org.apache.tapestry5.func;

/**
 * Interface for operation {@link Flow#map(Mapper)} to define how Flow elements are mapped from one type
 * to another (or otherwise transformed).
 *
 * This changed in 5.3 from an abstract base class to an interface.
 * 
 * @since 5.2.0
 * @param <S>
 *            type of source flow
 * @param <T>
 *            type of target (output) flow
 */
public interface Mapper<S, T>
{
    /**
     * Implemented in subclasses to map an element from the source flow to an element of the target
     * flow.
     */
    T map(S element);
}