Tree package:fgl

Tree-based implementation of Graph and DynGraph You will probably have better performance using the Data.Graph.Inductive.PatriciaTree implementation instead.
An efficient implementation of Graph using big-endian patricia tree (i.e. Data.IntMap). This module provides the following specialised functions to gain more performance, using GHC's RULES pragma:
Tree of shortest paths from a certain node to the rest of the (reachable) nodes. Corresponds to dijkstra applied to a heap in which the only known node is the starting node, with a path of length 0 leading to it. The edge labels of type b are the edge weights; negative edge weights are not supported.