BiDirectedGraph.php

<?php

namespace Gliph\Graph;

/**
 * Interface for bidirectional directed graph datastructures.
 */
interface BiDirectedGraph extends DirectedGraph {

    /**
     * Loops over each vertex that is inbound to the given vertex.
     *
     * The generator yields an edge as key and the adjacent vertex as value. The
     * form by which the edge is represented may vary from one graph
     * implementation to another, but the representation should be the same as
     * produced by the graph's eachEdge() implementation.
     *
     * @see Graph::eachEdge()
     *
     * @param object $vertex
     *   The vertex whose in-edges should be visited.
     *
     * @return \Generator
     *   A generator that yields the edge as key and adjacent vertex as value.
     *
     * @throws NonexistentVertexException
     *   Thrown if the vertex provided in the first parameter is not present in
     *   the graph.
     */
    public function eachInbound($vertex);

    /**
     * Loops over each vertex that is outbound from the given vertex.
     *
     * The generator yields an edge as key and the adjacent vertex as value. The
     * form by which the edge is represented may vary from one graph
     * implementation to another, but the representation should be the same as
     * produced by the graph's eachEdge() implementation.
     *
     * @see Graph::eachEdge()
     *
     * @param object $vertex
     *   The vertex whose out-edges should be visited.
     *
     * @return \Generator
     *   A generator that yields the edge as key and adjacent vertex as value.
     *
     * @throws NonexistentVertexException
     *   Thrown if the vertex provided in the first parameter is not present in
     *   the graph.
     */
    public function eachOutbound($vertex);

}