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upo-graphs/src/main/java/net/berack/upo/graph/VisitStrategy.java

45 lines
1.8 KiB
Java

package net.berack.upo.graph;
import java.util.function.Consumer;
import net.berack.upo.Graph;
import net.berack.upo.GraphDirected;
import net.berack.upo.graph.visit.VisitInfo;
/**
* This class is used for define some strategy for the visit of a graph.
*
* @param <V> The Object that represent a vertex
* @author Berack96
*/
public interface VisitStrategy<V> {
/**
* With this the graph will be visited accordingly to the strategy of the visit.<br>
* Some strategy can accept a source vertex null, because they visit all the graph anyway.<br>
* If you want to stop the visit of the graph, you just have to throw any exception in the visit function, but be sure to catch it
*
* @param graph the graph to visit
* @param source the vertex where the visit starts
* @param visit the function to apply at each vertex when they are visited
* @return an info of the view
* @throws NullPointerException if the graph is null
* @throws UnsupportedOperationException in the case that the visit algorithm cannot be applied to the graph
*/
VisitInfo<V> visit(Graph<V> graph, V source, Consumer<V> visit) throws NullPointerException, UnsupportedOperationException;
/**
* Method used for checking if the graph is Directed.<br>
* It's useful when the algorithm can only be applied to Directed graph.
*
* @param graph the instance of the graph to check
* @return the instance of the graph casted to a {@link GraphDirected}
* @throws UnsupportedOperationException in the case it's not a directed graph
*/
default GraphDirected<V> checkDirected(Graph<V> graph) {
if (graph instanceof GraphDirected)
return (GraphDirected<V>) graph;
throw new UnsupportedOperationException();
}
}