Move duplicate logic to base class

Author: clue

src/MinimumSpanningTree/Base.php

@@ -6,6 +6,8 @@
 use Fhaculty\Graph\Set\Edges;
 use Fhaculty\Graph\Exception\UnexpectedValueException;
 use Fhaculty\Graph\Edge\Directed as EdgeDirected;
+use Fhaculty\Graph\Edge\Base as Edge;
+use SplPriorityQueue;
 
 /**
  * Abstract base class for minimum spanning tree (MST) algorithms
@@ -51,4 +53,28 @@ abstract public function getEdges();
      * @return Graph
      */
     abstract protected function getGraph();
+
+    /**
+     * helper method to add a set of Edges to the given set of sorted edges
+     *
+     * @param Edges            $edges
+     * @param SplPriorityQueue $sortedEdges
+     * @throws UnexpectedValueException when encountering directed edges
+     */
+    protected function addEdgesSorted(Edges $edges, SplPriorityQueue $sortedEdges)
+    {
+        // For all edges
+        foreach ($edges as $edge) {
+            /* @var $edge Edge */
+            // ignore loops (a->a)
+            if (!$edge->isLoop()) {
+                if ($edge instanceof EdgeDirected) {
+                    throw new UnexpectedValueException('Minimum spanning tree for directed edges not supported');
+                }
+
+                // Add edges with negative weight because of order in stl
+                $sortedEdges->insert($edge, -$edge->getWeight());
+            }
+        }
+    }
 }

src/MinimumSpanningTree/Kruskal.php

@@ -40,18 +40,7 @@ public function getEdges()
         $sortedEdges = new SplPriorityQueue();
 
         // For all edges
-        foreach ($this->graph->getEdges() as $edge) {
-            // ignore loops (a->a)
-            if (!$edge->isLoop()) {
-                if ($edge instanceof EdgeDirected) {
-                    throw new UnexpectedValueException('Kruskal for directed edges not supported');
-                }
-                // Add edges with negativ Weight because of order in stl
-                $sortedEdges->insert($edge, -$edge->getWeight());
-            }
-        }
-
-        // $sortedEdges = $this->graph->getEdgesOrdered('weight');
+        $this->addEdgesSorted($this->graph->getEdges(), $sortedEdges);
 
         $returnEdges = array();
 

src/MinimumSpanningTree/Prim.php

@@ -40,15 +40,7 @@ public function getEdges()
 
             // get unvisited vertex of the edge and add edges from new vertex
             // Add all edges from $currentVertex to priority queue
-            foreach ($vertexCurrent->getEdges() as $currentEdge) {
-                if (!$currentEdge->isLoop()) {
-                    if ($currentEdge instanceof EdgeDirected) {
-                        throw new UnexpectedValueException('Unable to create MST for directed graphs');
-                    }
-                    // Add edges to priority queue with inverted weights (priority queue has high values at the front)
-                    $edgeQueue->insert($currentEdge, -$currentEdge->getWeight());
-                }
-            }
+            $this->addEdgesSorted($vertexCurrent->getEdges(), $edgeQueue);
 
             do {
                 try {