module Comparator

: sig

A type-indexed value that allows one to compare (and for generating error messages, serialize) values of the type in question.

One of the type parameters is a phantom parameter used to distinguish comparators potentially built on different comparison functions. In particular, we want to distinguish those using polymorphic compare and those using a monomorphic compare.

type ('a, 'witness) t = private {

# compare	: 'a -> 'a -> int	;
# sexp_of_t	: 'a -> Sexplib.Sexp.t	;

}

type ('a, 'b) comparator = ('a, 'b) t

module type S = sig

type t

type comparator_witness

val comparator : (t, comparator_witness) comparator

end

module type S1 = sig

type 'a t

type comparator_witness

val comparator : ('a t, comparator_witness) comparator

end

module Poly : S1 with type 'a t = 'a

module S_to_S1 : functor (S : S) -> S1 with type 'a t = S.t and type comparator_witness = S.comparator_witness

The Make functors mint fresh types that are used as the phantom comparator_witnesses.

module Make : functor (M : sig

type t

val sexp_of_t : t -> Sexplib.Sexp.t

val compare : t -> t -> int

end

) -> S with type t := M.t

module Make1 : functor (M : sig

type 'a t

val compare : 'a t -> 'a t -> int

val sexp_of_t : _ t -> Sexplib.Sexp.t

end

) -> S1 with type 'a t := 'a M.t

end