Module MoreLabels.Set

Sets over ordered types.

This module implements the set data structure, given a total ordering function over the set elements. All operations over sets are purely applicative (no side-effects). The implementation uses balanced binary trees, and is therefore reasonably efficient: insertion and membership take time logarithmic in the size of the set, for instance.

The Make functor constructs implementations for any type, given a compare function. 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 PairsSet = Set.Make(IntPairs)

  let m = PairsSet.(empty |> add (2,3) |> add (5,7) |> add (11,13))

module IntPairs = {
  type t = (int, int);
  let compare = ((x0, y0), (x1, y1)) =>
    switch (Stdlib.compare(x0, x1)) {
    | 0 => Stdlib.compare(y0, y1)
    | c => c
    };
};

module PairsSet = Set.Make(IntPairs);

let m = PairsSet.(empty |> add((2, 3)) |> add((5, 7)) |> add((11, 13)));

This creates a new module PairsSet, with a new type PairsSet.t of sets of int * int(int, int).

module type OrderedType = sig ... end

module type OrderedType = { ... };

Input signature of the functor Make.

module type S = sig ... end

module type S = { ... };

Output signature of the functor Make.

module Make
  (Ord : OrderedType) : 
  S with type elt = Ord.t and type t = Set.Make(Ord).t

module Make: 
   (Ord: OrderedType) =>
  S with type elt = Ord.t and type t = Set.Make(Ord).t;

Functor building an implementation of the set structure given a totally ordered type.