/* Copyright (c) 2010 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 com.google.wave.api;
import java.util.Map;
/**
* A function that computes a result object of type {@code V} from an input of
* type {@code K}.
*
* @param <K> the type of the function input.
* @param <V> the type of the function output.
*/
public interface Function<K, V> {
/**
* Computes {@code V} from the given {@code K}.
*
* @param source the source object.
* @return an instance of {@code V}, based on {@code source}.
*/
V call(K source);
/**
* A {@link Function} that computes a {@link BlipContent} from another
* {@link BlipContent}.
*
* Note: The sole purpose of this interface is to eliminate compiler warning
* about generic array of {@link Function} creation, since the {@code insert},
* {@code insertAfter}, {@code replace}, and {@code updateElements} method
* inside {@link BlipContentRefs} take a varargs of functions.
*/
static interface BlipContentFunction extends Function<BlipContent, BlipContent> { }
/**
* A {@link Function} that computes a {@link Map} from a {@link BlipContent}.
*
* Note: The sole purpose of this interface is to eliminate compiler warning
* about generic array of {@link Function} creation, since the {@code insert},
* {@code insertAfter}, {@code replace}, and {@code updateElements} method
* inside {@link BlipContentRefs} take a varargs of functions.
*/
static interface MapFunction extends Function<BlipContent, Map<String, String>> { }
}