This is a small collection of classical graph algorithms on digraphs in Nim.

The core abstractions representing a graph are some kind of not necessarily dense integer-like address space, some nodes iterator on the graph and some edges(graph, node) iterator on the kids of a node/destinations of arcs.

It also contains (also at the top level) gaPrioQ.nim since the shortest path algorithm made famous by Dijkstra needs a priority queue that can efficiently edit entry priorities and std/heapqueue does not allow this.

https://github.com/c-blake/thes has demos/tests of most of these algorithms, but a quick list is:

• arc/edge reversal
• topological sorting/testing for DAG/cyclicity
• transitive closure
• shortest path from beginning to end via BFS
• shortest path from beginning to end via Dijkstra
• components when viewed as an undirected graph
• min cost spanning tree of weighted, undirected graph

Should probably grow Max Flow, and weak strong components algorithms.