Functor Oper.Choose

module Choose: 
functor (G : sig
type t 
type vertex 
type edge 
val iter_vertex : (vertex -> unit) -> t -> unit
val iter_edges_e : (edge -> unit) -> t -> unit
end) -> sig .. end
Choose an element in a graph
Parameters:
G : sig type t type vertex type edge val iter_vertex : (vertex -> unit) -> t -> unit val iter_edges_e : (edge -> unit) -> t -> unit end

val choose_vertex : G.t -> G.vertex
choose_vertex g returns a vertex from the graph.
Raises Invalid_argument if the graph is empty.
val choose_edge : G.t -> G.edge
choose_edge g returns an edge from the graph.
Raises Invalid_argument if the graph has no edge.