Source file prereq.ml

(* Copyright (C) 2022  Petter A. Urkedal <paurkedal@gmail.com>
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version, with the LGPL-3.0 Linking Exception.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * and the LGPL-3.0 Linking Exception along with this library.  If not, see
 * <http://www.gnu.org/licenses/> and <https://spdx.org>, respectively.
 *)

let (%) f g x = f (g x)

module List = struct
  include List
  let rec fold f = function [] -> Fun.id | x :: xs -> fold f xs % f x
end

module Seq = struct
  include Seq
  let rec fold f xq =
    match xq () with Nil -> Fun.id | Cons (x, xq') -> fold f xq' % f x
end