/*
 * 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 AnnotationTransformer transforms an annotation definition into one or many other annotation definitions discarding the original annotation. 
Unlike AnnotationMapper which retains the original annotation information this interface can be used to optimize produced annotation metadata and discard unnecessary annotations.
Author:
graemerocher
Type parameters:
<T> – The annotation type
See Also:
AnnotationMapper
Since:
2.0/**
 * An {@code AnnotationTransformer} transforms an annotation definition into one or many other annotation
 * definitions discarding the original annotation.
 *
 * <p>Unlike {@link AnnotationMapper} which retains the original annotation information this interface can
 * be used to optimize produced annotation metadata and discard unnecessary annotations.</p>
 *
 * @since 2.0
 * @author graemerocher
 * @see AnnotationMapper
 * @param <T> The annotation type
 */
public interface AnnotationTransformer<T extends Annotation> {

    
The transform 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 transform 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<AnnotationValue<?>> transform(AnnotationValue<T> annotation, VisitorContext visitorContext);
}