 where
 	SearchSpace.VertexId: IdIndexable,
 	EdgeWeightMap.Graph == SearchSpace,
-	EdgeWeightMap.Value == Distance,
+	EdgeWeightMap.Value == PathLength,
 	VertexDistanceMap.Graph == SearchSpace,
-	VertexDistanceMap.Value == Distance,
+	VertexDistanceMap.Value == PathLength,
 	Visitor.Graph == SearchSpace
 {
 	/// The graph we're operating on is `SearchSpace`.

	/// The queue of verticies to visit.
	var queue = ConfigurableHeap<
		SearchSpace.VertexId,
		Distance,
		Int32,  // TODO: make configurable!
		_IdIndexibleDictionaryHeapIndexer<SearchSpace.VertexId, _ConfigurableHeapCursor<Int32>>>()
	/// The weights of the edges.

	}

	public mutating func discover(vertex: SearchSpace.VertexId, _ graph: inout Graph) throws {
		queue.add(vertex, with: PathLength.effectiveInfinity)  // Add to the back of the queue.
		try visitor.discover(vertex: vertex, &graph)
	}

