package org.eclipse.aether.collection;

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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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 * 
 *  http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing,
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import org.eclipse.aether.graph.Dependency;

Decides whether the dependencies of a dependency node should be traversed as well.

Note: Implementations must be stateless.

Warning: This hook is called from a hot spot and therefore implementations should pay attention to performance. Among others, implementations should provide a semantic equals() method. 
See Also:
RepositorySystemSession.getDependencyTraverser()
RepositorySystem.collectDependencies(RepositorySystemSession, CollectRequest)/**
 * Decides whether the dependencies of a dependency node should be traversed as well.
 * <p>
 * <strong>Note:</strong> Implementations must be stateless.
 * <p>
 * <em>Warning:</em> This hook is called from a hot spot and therefore implementations should pay attention to
 * performance. Among others, implementations should provide a semantic {@link Object#equals(Object) equals()} method.
 * 
 * @see org.eclipse.aether.RepositorySystemSession#getDependencyTraverser()
 * @see org.eclipse.aether.RepositorySystem#collectDependencies(org.eclipse.aether.RepositorySystemSession,
 *      CollectRequest)
 */
public interface DependencyTraverser
{

    
Decides whether the dependencies of the specified dependency should be traversed.
Params:
dependency – The dependency to check, must not be null.
Returns:
true if the dependency graph builder should recurse into the specified dependency and process its dependencies, false otherwise./**
     * Decides whether the dependencies of the specified dependency should be traversed.
     * 
     * @param dependency The dependency to check, must not be {@code null}.
     * @return {@code true} if the dependency graph builder should recurse into the specified dependency and process its
     *         dependencies, {@code false} otherwise.
     */
    boolean traverseDependency( Dependency dependency );

    
Derives a dependency traverser that will be used to decide whether the transitive dependencies of the dependency
given in the collection context shall be traversed. When calculating the child traverser, implementors are
strongly advised to simply return the current instance if nothing changed to help save memory.
Params:
context – The dependency collection context, must not be null.
Returns:
The dependency traverser for the target node or null if dependencies should be unconditionally traversed in the sub graph./**
     * Derives a dependency traverser that will be used to decide whether the transitive dependencies of the dependency
     * given in the collection context shall be traversed. When calculating the child traverser, implementors are
     * strongly advised to simply return the current instance if nothing changed to help save memory.
     * 
     * @param context The dependency collection context, must not be {@code null}.
     * @return The dependency traverser for the target node or {@code null} if dependencies should be unconditionally
     *         traversed in the sub graph.
     */
    DependencyTraverser deriveChildTraverser( DependencyCollectionContext context );

}