Module `Core_kernel__.Comparable`

Comparable extends Base.Comparable and provides functions for comparing like types.

Usage example:

module Foo = struct
  module T = struct
    type t = ... [@@deriving compare, sexp]
  end
  include T
  include Comparable.Make (T)
end

Then include Comparable.S in the signature (see Comparable_intf for an example).

To add an Infix submodule:

module C = Comparable.Make (T)
include C
module Infix = (C : Comparable.Infix with type t := t)

Common pattern: Define a module O with a restricted signature. It aims to be (locally) opened to bring useful operators into scope without shadowing unexpected variable names. E.g. in the Date module:

module O = struct
  include (C : Comparable.Infix with type t := t)
  let to_string t = ..
end

Opening Date would shadow now, but opening Date.O doesn't:

let now = .. in
let someday = .. in
Date.O.(now > someday)

module type Infix = Core_kernel__.Comparable_intf.Infix

module type Map_and_set_binable = Core_kernel__.Comparable_intf.Map_and_set_binable

module type Polymorphic_compare = Core_kernel__.Comparable_intf.Polymorphic_compare

module type S_plain = Core_kernel__.Comparable_intf.S_plain

module type S = Core_kernel__.Comparable_intf.S

module type S_binable = Core_kernel__.Comparable_intf.S_binable

module type S_common = Core_kernel__.Comparable_intf.S_common

module type Validate = Core_kernel__.Comparable_intf.Validate

module type With_zero = Core_kernel__.Comparable_intf.With_zero

val lexicographic : ('a -> 'a -> int) list -> 'a -> 'a -> int: lexicographic cmps x y compares x and y lexicographically using functions in the list cmps.

val lift : ('a -> 'a -> 'int_or_bool) -> f:('b -> 'a) -> 'b -> 'b -> 'int_or_bool: lift cmp ~f x y compares x and y by comparing f x and f y via cmp.

module Inherit : functor (C : sig ... end) -> functor (T : sig ... end) -> S with type t := T.t: Inherit comparability from a component.

Make Functors

The Comparable Make functor family allows users to choose among the following attributes:

*_using_comparator or not
*_binable or not
*_plain or not

Thus there are functors like Make_plain or Make_binable_using_comparator, etc.

module Make_plain : functor (T : sig ... end) -> S_plain with type t := T.t

module Make : functor (T : sig ... end) -> S with type t := T.t

module Make_plain_using_comparator : functor (T : sig ... end) -> S_plain with type t := T.t with type comparator_witness := T.comparator_witness

module Make_using_comparator : functor (T : sig ... end) -> S with type t := T.t with type comparator_witness := T.comparator_witness

module Make_binable : functor (T : sig ... end) -> S_binable with type t := T.t

module Make_binable_using_comparator : functor (T : sig ... end) -> S_binable with type t := T.t with type comparator_witness := T.comparator_witness

module Extend : functor (M : Base.Comparable.S) -> functor (X : sig ... end) -> S with type t := M.t with type comparator_witness := M.comparator_witness

module Extend_binable : functor (M : Base.Comparable.S) -> functor (X : sig ... end) -> S_binable with type t := M.t with type comparator_witness := M.comparator_witness

module Map_and_set_binable : functor (T : sig ... end) -> Map_and_set_binable with type t := T.t

module Map_and_set_binable_using_comparator : functor (T : sig ... end) -> Map_and_set_binable with type t := T.t with type comparator_witness := T.comparator_witness

module Poly : functor (T : sig ... end) -> S with type t := T.t

module Validate : functor (T : sig ... end) -> Validate with type t := T.t

module With_zero : functor (T : sig ... end) -> With_zero with type t := T.t

module Validate_with_zero : functor (T : sig ... end) -> sig ... end

module Stable : sig ... end