Digraph edges notation

[bjorng]

@stevensonmt

I’m curious why that’s not the default behavior of add_edge/3 though? Implicitly naming an edge with {from, to} has to be more intuitive than whatever [:"$e" | N] is meant to convey.

Using the {from, to} naming scheme will not work in general, because the :digraph module supports having any number of distinct edges between each pair of vertices.