Module Map

module Map: sig .. end
Association tables over ordered types.

This module implements applicative association tables, also known as finite maps or dictionaries, given a total ordering function over the keys. All operations over maps are purely applicative (no side-effects). The implementation uses balanced binary trees, and therefore searching and insertion take time logarithmic in the size of the map.

For instance:

     module IntPairs =
         type t = int * int
         let compare (x0,y0) (x1,y1) =
           match x0 x1 with
               0 -> y0 y1
             | c -> c

     module PairsMap = Map.Make(IntPairs)

     let m = PairsMap.(empty |> add (0,1) "hello" |> add (1,0) "world")

This creates a new module PairsMap, with a new type 'a PairsMap.t of maps from int * int to 'a. In this example, m contains string values so its type is string PairsMap.t.

module type OrderedType = sig .. end
Input signature of the functor Map.Make.
module type S = sig .. end
Output signature of the functor Map.Make.
module Make: 
functor (Ord : OrderedType) -> S with type key = Ord.t
Functor building an implementation of the map structure given a totally ordered type.