Functor Structure.Open

module Open: functor (Shape : Shape) -> functor (Data : Internal  with type 'a structure := 'a Shape.structure) -> External  with type t := Data.t
              and type 'a key := 'a Shape.k

Opens an internal tree module into an external one.

Parameters:

`Shape`	:	`Shape`
`Data`	:	`Internal with type 'a structure := 'a Shape.structure`

type t

type 'a key

val mem : 'a key -> bool

val get : 'a key -> (t -> 'a) option

val set : 'a key ->
       'a -> t -> t