/*
 * Copyright (C) 2012-2013 The Project Lombok Authors.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package lombok.experimental;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.*;

import lombok.core.FlagUsageType;
import lombok.core.configuration.ConfigurationKey;

/**
 * Extension methods enable you to "add" methods to existing types without creating a new derived type, recompiling, or
 * otherwise modifying the original type. Extension methods are a special kind of static method, but they are called as
 * if they were instance methods on the extended type.
 * <p>
 * Complete documentation is found at <a href="http://projectlombok.org/features/experimental/ExtensionMethod.html">the project lombok features page for &#64;ExtensionMethod</a>.
 * <p>
 * <p>
 * Before:
 * 
 * <pre>
 * &#064;ExtensionMethod(java.util.Arrays.class)
 * class Example {
 * 	private void example() {
 * 		long[] values = new long[] { 2, 5, 7, 9 };
 * 		values.copyOf(3).sort();
 * 	}
 * }
 * </pre>
 * 
 * After:
 * 
 * <pre>
 * class Example {
 * 	private void example() {
 * 		long[] values = new long[] { 2, 5, 7, 9 };
 * 		java.util.Arrays.sort(java.util.Arrays.copyOf(values, 3));
 * 	}
 * }
 * </pre>
 */
@Target(TYPE)
@Retention(SOURCE)
public @interface ExtensionMethod {
	/**
	 * lombok configuration: {@code lombok.ExtensionMethod.flagUsage} = {@code WARNING} | {@code ERROR}.
	 * 
	 * If set, <em>any</em> usage of {@code @ExtensionMethod} results in a warning / error.
	 */
	ConfigurationKey<FlagUsageType> FLAG_USAGE = new ConfigurationKey<FlagUsageType>("lombok.ExtensionMethod.flagUsage") {};
	
	/** All types whose static methods will be exposed as extension methods. */
	Class<?>[] value();

	/**
	 * If {@code true}, an applicable extension method is used (if found) even if the method call already was compilable (this is the default).
	 * If {@code false}, an extension method is only used if the method call is not also defined by the type itself.
	 */
	boolean suppressBaseMethods() default true;
}