Source file read_only_intf.ml

(*
 * Copyright (c) 2013-2022 Thomas Gazagnaire <thomas@gazagnaire.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *)

open Import
open Store_properties

module type S = sig
  (** {1 Read-only stores}

      Read-only stores are store where it is only possible to read existing
      values. *)

  type -'a t
  (** The type for stores. The ['a] phantom type carries information about the
      store mutability. *)

  type key
  (** The type for keys. *)

  type value
  (** The type for raw values. *)

  val mem : [> read ] t -> key -> bool Lwt.t
  (** [mem t k] is true iff [k] is present in [t]. *)

  val find : [> read ] t -> key -> value option Lwt.t
  (** [find t k] is [Some v] if [k] is associated to [v] in [t] and [None] is
      [k] is not present in [t]. *)

  include Closeable with type 'a t := 'a t
  (** @inline *)
end

module type Maker = functor (Key : Type.S) (Value : Type.S) -> sig
  include S with type key = Key.t and type value = Value.t

  include Of_config with type 'a t := 'a t
  (** @inline *)
end

module type Sigs = sig
  module type S = S
  module type Maker = Maker
end