(* Copyright (C) 2004, 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://helm.cs.unibo.it/
 *)

exception Not_implemented of string
let not_implemented feature = raise (Not_implemented feature)

  (** exceptions whose content should be presented to the user *)
exception Failure of string
let error s = raise (Failure s)
let warning s = prerr_endline ("MATITA WARNING: " ^ s)

exception No_proof  (** no current proof is available *)
exception No_choice (** no choice was made by the user *)

class type observer =
  (* "observer" pattern *)
  object
    method update: unit -> unit
  end

class subject =
  (* "observer" pattern *)
  object
    val mutable observers = []
    method attach (o: observer) = observers <- o :: observers
    method detach (o: observer) =
      observers <- List.filter (fun o' -> o' != o) observers
    method notify () = List.iter (fun o -> o#update ()) observers
  end

class type command =
  (* "command" pattern *)
  object
    method execute: unit -> unit
    method undo: unit -> unit
  end

class type parserr =  (* "parser" is a keyword :-( *)
  object
    method parseTerm:     char Stream.t -> DisambiguateTypes.term
    method parseTactic:   char Stream.t -> DisambiguateTypes.tactic
    method parseTactical: char Stream.t -> DisambiguateTypes.tactical
    method parseCommand:  char Stream.t -> DisambiguateTypes.command
    method parseScript:   char Stream.t -> DisambiguateTypes.script
  end

class type disambiguator =
  object
    method parserr: parserr
    method setParserr: parserr -> unit

    method disambiguateTerm:
      context:Cic.context -> metasenv:Cic.metasenv ->
      ?env:DisambiguateTypes.environment ->
        char Stream.t ->
          (DisambiguateTypes.environment * Cic.metasenv * Cic.term) list
    method disambiguateTermAst:
      context:Cic.context -> metasenv:Cic.metasenv ->
      ?env:DisambiguateTypes.environment ->
        DisambiguateTypes.term ->
          (DisambiguateTypes.environment * Cic.metasenv * Cic.term) list
  end

(** {2 shorthands} *)

type namer = ProofEngineTypes.mk_fresh_name_type

type choose_uris_callback =
  selection_mode:Gtk.Tags.selection_mode ->
  ?title:string -> ?msg:string -> ?nonvars_button:bool ->
  string list ->
    string list

type choose_interp_callback = (string * string) list list -> int list