76 lines
3.1 KiB
OCaml
76 lines
3.1 KiB
OCaml
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(* Copyright (C) 2022 Petter A. Urkedal <paurkedal@gmail.com>
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*
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* This library is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or (at your
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* option) any later version, with the LGPL-3.0 Linking Exception.
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*
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* This library is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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* License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* and the LGPL-3.0 Linking Exception along with this library. If not, see
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* <http://www.gnu.org/licenses/> and <https://spdx.org>, respectively.
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*)
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(** Concurrent stream signature. *)
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module type S = sig
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type +'a fiber
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type ('a, 'err) t = unit -> ('a, 'err) node fiber
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(** A stream, represented as a lazy chain of {!Cons}-nodes terminating in a
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{!Nil} or an {!Error}. *)
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and ('a, 'err) node =
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| Nil (** The node of an empty stream *)
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| Error of 'err (** A node of a permanently failed stream. *)
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| Cons of 'a * ('a, 'err) t
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(** A node holding the next element and continuation of a stream. *)
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val fold :
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f: ('a -> 'state -> 'state) ->
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('a, 'err) t ->
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'state ->
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('state, 'err) result fiber
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(** [fold ~f stream acc] consumes the remainder elements [e1], ..., [eN] of
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[stream] and returns [Ok (acc |> f e1 |> ... |> f eN)] if no error
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occurred *)
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val fold_s :
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f: ('a -> 'state -> ('state, 'err) result fiber) ->
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('a, 'clog) t ->
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'state ->
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('state, [> `Congested of 'clog ] as 'err) result fiber
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(** [fold_s ~f stream acc] consumes the remainder of [stream], passing each
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element in order to [f] along with the latest accumulation starting at
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[acc], and returning the final accumulation if successful. An error
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result may be due to either the stream provider or the callback, as
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distinguished with the [`Congested] constructor. *)
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val iter_s :
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f: ('a -> (unit, 'err) result fiber) ->
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('a, 'clog) t ->
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(unit, [> `Congested of 'clog ] as 'err) result fiber
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(** [iter_s ~f stream] consumes the remainder of [stream], passing each
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element in order to [f]. An error result may be due to either the steram
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provider or the callback, as distinguished with the [`Congested]
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constructor. *)
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val to_rev_list : ('a, 'err) t -> ('a list, 'err) result fiber
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(** [to_rev_list stream] consumes the remainder of [stream], returning a list
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of its element in reverse order of production. *)
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val to_list : ('a, 'err) t -> ('a list, 'err) result fiber
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(** [to_list stream] consumes the remainder of [stream], returning a list of
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its element in order of production. *)
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val of_list : 'a list -> ('a, 'err) t
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(** [of_list xs] is a non-failing finite stream (re)producing the elements
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[xs] in order of occurrence. *)
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val map_result : f: ('a -> ('b, 'err) result) -> ('a, 'err) t -> ('b, 'err) t
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end
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