pathTo ignores .withDirection(GraphTraversal.AnyConnected)

[matthewrj]

pathTo and shortestPathTo do not find a path if there is a path going the opposite direction to the edges and .withDirection(GraphTraversal.AnyConnected) is provided.

val g = Graph(1 ~> 2)
val path = g.get(2).withDirection(GraphTraversal.AnyConnected).pathTo(g.get(1))
println(path) // -> None

[peter-empen]

Hi Matthew,

this behaviour is intentional - sorry for not having documented it explicitely. Here are the reasons:

Examining the Path type you will realize that it contains the inner nodes and, lazily, the inner edges that are on a path of the given graph. The library is designed such that you cannot compose a Path that contains non-existing nodes or edges with respect to the underlying graph. So pathTo and shortestPathTo can never return a non-existing path.

To achieve the desired result, you could build an inverse respectively undirected graph prior to calling pathTo or shortestPathTo.

More efficienly, a new Path method inverse could be added to the Path class that returns a sequence of nodes/edges. Certainly you can achieve this on your own as well.

Just tell me how to proceed.