/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016. Diorite (by Bartłomiej Mazur (aka GotoFinal))
 *
 * 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 org.diorite.inject;

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;


import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Identifies qualifier annotations. Anyone can define a new qualifier. A
 * qualifier annotation:
 *
 * <ul>
 *   <li>is annotated with {@code @Qualifier}, {@code @Retention(RUNTIME)},
 *      and typically {@code @Documented}.</li>
 *   <li>can have attributes.</li>
 *   <li>may be part of the public API, much like the dependency type, but
 *      unlike implementation types which needn't be part of the public
 *      API.</li>
 *   <li>may have restricted usage if annotated with {@code @Target}. While
 *      this specification covers applying qualifiers to fields and
 *      parameters only.</li>
 * </ul>
 *
 * <p>For example:
 *
 * <pre>
 *   @java.lang.annotation.Documented
 *   @java.lang.annotation.Retention(RUNTIME)
 *   @org.diorite.inject.Qualifier
 *   public @interface Leather {
 *     Color color() default Color.TAN;
 *     public enum Color { RED, BLACK, TAN }
 *   }</pre>
 *
 * @see Named @Named
 */
@Target(ANNOTATION_TYPE)
@Retention(RUNTIME)
@Documented
public @interface Qualifier {}