struct
  

(** Example: call "gunzip <list of fastq.gz files> > some_name_cat.fastq". *)


  let concat ~(run_with : Machine.t) bunch_of_dot_gzs ~result_path =
    let open KEDSL in
    let program =
      Program.(
        exec ["mkdir"; "-p"; Filename.dirname result_path]
        && shf "gunzip -c  %s > %s"
          (List.map bunch_of_dot_gzs
             ~f:(fun o -> Filename.quote o#product#path)
           |> String.concat ~sep:" ") result_path
      ) in
    let name =
      sprintf "gunzipcat-%s" (Filename.basename result_path) in
    workflow_node
      (single_file result_path ~host:Machine.(as_host run_with))
      ~name
      ~make:(Machine.run_stream_processor ~name run_with  program)
      ~edges:(
        on_failure_activate Remove.(file ~run_with result_path)
        :: List.map ~f:depends_on bunch_of_dot_gzs)
end