module Make:
type node
type edge = node * node
val mknode : B.t -> node
creates an abstract node from a boxlike
val place : ?orient:[ `BT | `LR | `RL | `TB ] ->
node list ->
edge list -> B.t list * Path.t list
place ~orient nodes edges returns a concrete
representation of the abstract directed graph composed by
nodes linked by edges. The concrete representation is
composed by the list of all the boxlikes of nodes placed
by dot and by the list of paths representing the edges
drawn by dot
orient : specifies the orientation of the graph :
- `TB top to bottom (default)
- `LR left to right
- `BT bottom to top
- `RL right to left