backtracking/ocamlgraph — pull request #2 by carlpulley (2013-06-06 17:04:10+00:00)
Title: Modifications to allow subgraphs to be nested

Graphviz allows subgraphs to be nested. Currently, Ocamlgraph doesn't support this.

This PR allows nesting of subgraphs by introducing an sg_parent field to the subgraph record data structure.