/*
 * Copyright 2017-2020 original authors
 *
 * 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
 *
 * https://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 io.micronaut.inject.annotation;

import io.micronaut.core.annotation.AnnotationValue;
import io.micronaut.inject.visitor.VisitorContext;

import java.lang.annotation.Annotation;
import java.util.List;

An AnnotationMapper is a type that is capable of mapping a given annotation to one or many annotations at compile time. 
Use cases include if you wish to support different annotation types or specifications but wish to map them a common internal annotation annotation.
For example to support the JPA spec you may wish to map the PersistenceContext annotation to one or many other internal annotations with relying specifically on the JPA specification.
AnnotationMapper instances can be registered with the service loader pattern via META-INF/services and will be picked up at compile time and should implement either NamedAnnotationMapper or TypedAnnotationMapper
Author:
graemerocher
Type parameters:
<T> – The annotation type
See Also:
NamedAnnotationMapper
TypedAnnotationMapper
Since:
1.0/**
 * An {@code AnnotationMapper} is a type that is capable of mapping a given annotation to one or many annotations at compile time.
 *
 * <p>Use cases include if you wish to support different annotation types or specifications but wish to map them a common internal annotation annotation.</p>
 *
 * <p>For example to support the JPA spec you may wish to map the {@code PersistenceContext} annotation to one or many other internal annotations with relying specifically on the JPA specification.</p>
 *
 * <p>AnnotationMapper instances can be registered with the service loader pattern via {@code META-INF/services} and will be picked up at compile time and should implement
 * either {@link NamedAnnotationMapper} or {@link TypedAnnotationMapper}</p>
 *
 * @author graemerocher
 * @since 1.0
 * @param <T> The annotation type
 * @see NamedAnnotationMapper
 * @see TypedAnnotationMapper
 */
public interface AnnotationMapper<T extends Annotation> {

    
The map method will be called for each instances of the annotation returned via this method.
Params:
annotation – The annotation values
visitorContext – The context that is being visited
Returns:
A list of zero or many annotations and values to map to/**
     * The map method will be called for each instances of the annotation returned via this method.
     *
     * @param annotation The annotation values
     * @param visitorContext The context that is being visited
     * @return A list of zero or many annotations and values to map to
     */
    List<io.micronaut.core.annotation.AnnotationValue<?>> map(AnnotationValue<T> annotation, VisitorContext visitorContext);
}