Topological.Make
Functor providing topological iterators over a graph.
fold action g seed
allows iterating over the graph g
in topological order. action node accu
is called repeatedly, where node
is the node being visited, and accu
is the result of the action
's previous invocation, if any, and seed
otherwise. If g
contains cycles, the order is unspecified inside the cycles and every node in the cycles will be presented exactly once.
Not tail-recursive. Complexity: O(V+E)