public static void DeleteVerticesAndMergeEdges <TVertex, TEdge>
(this IMutableBidirectionalGraph <TVertex, TEdge> graph, TVertex vertexToDelete,
Func <TEdge, TEdge, TEdge> mergeFunc)
where TEdge : IEdge <TVertex>
{
if (graph.IsInEdgesEmpty(vertexToDelete) || graph.IsOutEdgesEmpty(vertexToDelete))
{
//simple case
graph.RemoveVertex(vertexToDelete);
}
else
{
//need to keep connections
var newEdges = from e1 in graph.InEdges(vertexToDelete)
from e2 in graph.OutEdges(vertexToDelete)
select mergeFunc(e1, e2);
//create edges
var newEdgesList = newEdges.ToList();
graph.AddEdgeRange(newEdgesList);
graph.RemoveVertex(vertexToDelete);
}
}