functor
(G : sig
type t
type vertex
type edge
val iter_vertex :
(Oper.Choose.vertex -> unit) -> Oper.Choose.t -> unit
val iter_edges_e :
(Oper.Choose.edge -> unit) -> Oper.Choose.t -> unit
end) ->
sig val choose_vertex : G.t -> G.vertex val choose_edge : G.t -> G.edge end