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module type Basic = Monoid_intf.Basic
module type S = Monoid_intf.S
module Make (M : Basic) : Monoid_intf.S with type t = M.t = struct
include M
module O = struct
let ( @ ) = combine
end
let reduce = List.fold_left ~init:empty ~f:combine
let map_reduce ~f =
List.fold_left ~init:empty ~f:(fun acc a -> combine acc (f a))
end
[@@inlined always]
module Exists = Make (struct
type t = bool
let empty = false
let combine = ( || )
end)
module Forall = Make (struct
type t = bool
let empty = true
let combine = ( && )
end)
module String = Make (struct
type t = string
let empty = ""
let combine = ( ^ )
end)
module List (M : sig
type t
end) : Monoid_intf.S with type t = M.t list = Make (struct
type t = M.t list
let empty = []
let combine = ( @ )
end)
module Appendable_list (M : sig
type t
end) : Monoid_intf.S with type t = M.t Appendable_list.t = Make (struct
type t = M.t Appendable_list.t
let empty = Appendable_list.empty
let combine = Appendable_list.( @ )
end)
module Unit : Monoid_intf.S with type t = Unit.t = Make (struct
include Unit
let empty = ()
let combine () () = ()
end)
module Add (M : sig
type t
val zero : t
val ( + ) : t -> t -> t
end) : Monoid_intf.S with type t = M.t = Make (struct
include M
let empty = zero
let combine = ( + )
end)
module Mul (M : sig
type t
val one : t
val ( * ) : t -> t -> t
end) : Monoid_intf.S with type t = M.t = Make (struct
include M
let empty = one
let combine = ( * )
end)
module Union (M : sig
type t
val empty : t
val union : t -> t -> t
end) : Monoid_intf.S with type t = M.t = Make (struct
include M
let combine = union
end)
module Product (A : Monoid_intf.Basic) (B : Monoid_intf.Basic) :
Monoid_intf.S with type t = A.t * B.t = Make (struct
type t = A.t * B.t
let empty = (A.empty, B.empty)
let combine (a1, b1) (a2, b2) = (A.combine a1 a2, B.combine b1 b2)
end)
module Product3
(A : Monoid_intf.Basic)
(B : Monoid_intf.Basic)
(C : Monoid_intf.Basic) : Monoid_intf.S with type t = A.t * B.t * C.t =
Make (struct
type t = A.t * B.t * C.t
let empty = (A.empty, B.empty, C.empty)
let combine (a1, b1, c1) (a2, b2, c2) =
(A.combine a1 a2, B.combine b1 b2, C.combine c1 c2)
end)
module Function (A : sig
type t
end)
(M : Monoid_intf.Basic) : Monoid_intf.S with type t = A.t -> M.t = Make (struct
type t = A.t -> M.t
let empty _ = M.empty
let combine f g x = M.combine (f x) (g x)
end)
module Endofunction = struct
module Left (A : sig
type t
end) : Monoid_intf.S with type t = A.t -> A.t = Make (struct
type t = A.t -> A.t
let empty x = x
let combine f g x = g (f x)
end)
module Right (A : sig
type t
end) : Monoid_intf.S with type t = A.t -> A.t = Make (struct
type t = A.t -> A.t
let empty x = x
let combine f g x = f (g x)
end)
end