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 = struct type t = int * int let compare (x0,y0) (x1,y1) = match Stdlib.compare x0 x1 with 0 -> Stdlib.compare y0 y1 | c -> c end 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: (Ord: OrderedType) => S with type key = Ord.t;
Functor building an implementation of the map structure given a totally ordered type.