let
  pkgs = (import <nixpkgs> { });
  inherit (pkgs) stdenv lib;
  ocamlformat =
    let
      ocamlformat_version =
        let
          lists = pkgs.lib.lists;
          strings = pkgs.lib.strings;
          ocamlformat_config = strings.splitString "\n" (builtins.readFile ./.ocamlformat);
          prefix = "version=";
          ocamlformat_version_pred = line: strings.hasPrefix prefix line;
          version_line = lists.findFirst ocamlformat_version_pred "not_found" ocamlformat_config;
          version = strings.removePrefix prefix version_line;
        in
        builtins.replaceStrings ["."] ["_"] version;
    in builtins.getAttr ("ocamlformat_" + ocamlformat_version) pkgs;
in ocamlformat