module type GRAPH = sig end
The client must provide an implementation of graphs which fullfills the
signature GRAPH.
type graph
type node
type edge
val iter_nodes : (node -> unit) -> graph -> unit
val iter_edges : (edge -> unit) -> graph -> unit
val node_hash : node -> int
val node_equal : node -> node -> bool
val node_attributes : node -> Avl_draw.node_attributes
val edge_hash : edge -> int
val edge_equal : edge -> edge -> bool
val edge_head : edge -> node
val edge_tail : edge -> node
val edge_attributes : edge -> Avl_draw.edge_attributes