You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
52 lines
989 B
52 lines
989 B
3 years ago
|
(*
|
||
|
|
* Copyright (c) Facebook, Inc. and its affiliates.
|
||
|
|
*
|
||
|
|
* This source code is licensed under the MIT license found in the
|
||
|
|
* LICENSE file in the root directory of this source tree.
|
||
|
|
*)
|
||
|
|
|
||
|
|
include Monad_intf
|
||
|
|
|
||
|
|
module Make (M : sig
|
||
|
|
type 'a t
|
||
|
|
|
||
|
|
val return : 'a -> 'a t
|
||
|
|
val bind : 'a t -> ('a -> 'b t) -> 'b t
|
||
|
|
end) =
|
||
|
|
struct
|
||
|
|
include M
|
||
|
|
|
||
|
|
let map f m = bind m (fun a -> return (f a))
|
||
|
|
let ap m n = bind m (fun f -> bind n (fun a -> return (f a)))
|
||
|
|
let prod m n = bind m (fun a -> bind n (fun b -> return (a, b)))
|
||
|
|
|
||
|
|
module Import = struct
|
||
|
|
let ( |>= ) m f = map f m
|
||
|
|
let ( >>= ) = bind
|
||
|
|
let ( let* ) = bind
|
||
|
|
let ( and* ) = prod
|
||
|
|
let ( let+ ) = ( |>= )
|
||
|
|
let ( and+ ) = prod
|
||
|
|
end
|
||
|
|
|
||
|
|
let bind m ~f = bind m f
|
||
|
|
let map m ~f = map f m
|
||
|
|
end
|
||
|
|
|
||
|
|
module State (State : sig
|
||
|
|
type t
|
||
|
|
end) =
|
||
|
|
struct
|
||
|
|
include Make (struct
|
||
|
|
type 'a t = State.t -> 'a * State.t
|
||
|
|
|
||
|
|
let return a s = (a, s)
|
||
|
|
|
||
|
|
let bind m k s =
|
||
|
|
let a, s = m s in
|
||
|
|
k a s
|
||
|
|
end)
|
||
|
|
|
||
|
|
let run m s = m s
|
||
|
|
end
|