(* Copyright (C) 2000, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * HELM 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://www.cs.unibo.it/helm/.
 *)

(*
 * implementazione del comando SORTEDBY
 *)

open MathQL;;
open Func;;
open Utility;;

(*
 * implementazione del comando SORTEDBY
 *)
let sortedby_ex alist order afunc =
 let before = Sys.time () in
  let res = 
   let module S = Mathql_semantics in
    (Sort.list
     (fun {S.extra = e1} {S.extra = e2} ->
      match order with
         MQAsc  -> e1 < e2
       | MQDesc -> e1 > e2
     )
     (List.map
      (fun {S.uri = u ; S.attributes = attr} -> {S.uri = u ; S.attributes = attr ; S.extra = (apply_func afunc u)})
      alist
     )
    )
  in
   let after = Sys.time ()
   and ll1 = string_of_int (List.length alist) in
    let diff = string_of_float (after -. before) in
     print_endline
      ("SORTEDBY(" ^ ll1 ^ ") = " ^ string_of_int (List.length res) ^
       ": " ^ diff ^ "s") ;
     flush stdout ;
     res
;;