(* 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://cs.unibo.it/helm/.
 *)

(*  AUTOR: Ferruccio Guidi <fguidi@cs.unibo.it>
 *)

type arity_t = Const of int 
             | Positive
	     | Any

type eval_spec = {eval : MathQL.query -> MathQL.result;
                  conn : MQIConn.handle
		 }

type text_out_spec = {out    : string -> unit;
                      path   : (string -> unit) -> MathQL.path -> unit;
		      query  : (string -> unit) -> string -> MathQL.query -> unit;
		      result : (string -> unit) -> string -> MathQL.result -> unit
		     }

type text_in_spec = {result_in : Lexing.lexbuf -> MathQL.result}

val fun_arity   : MathQL.path -> int -> int -> unit

val fun_eval    : eval_spec -> text_out_spec -> text_in_spec -> 
                  MathQL.path -> MathQL.path list -> MathQL.query list -> 
	          MathQL.result

val fun_txt_out : text_out_spec ->
		  MathQL.path -> MathQL.path list -> MathQL.query list -> unit

val gen_arity   : MathQL.path -> int -> unit

val gen_eval    : eval_spec ->
                  MathQL.path -> MathQL.query list -> MathQL.query

exception ArityError of MathQL.path * arity_t * int

exception NameError of MathQL.path

type std_text_out_spec = {s_out    : string -> unit;
                          s_path   : MathQL.path -> unit;
	 	          s_query  : MathQL.query -> unit;
		          s_result : MathQL.result -> unit
}

val std : text_out_spec -> std_text_out_spec

(* function registration ****************************************************)

type fun_spec = {arity_p : arity_t;
                 arity_s : arity_t;
                 body    : eval_spec -> text_out_spec -> text_in_spec ->
		           MathQL.path list -> MathQL.query list -> MathQL.result;
		 txt_out : text_out_spec ->  
		           MathQL.path list -> MathQL.query list -> unit
		}

val fun_register : MathQL.path -> fun_spec -> unit

val fun_arity0   : MathQL.path -> string -> MathQL.result -> fun_spec

val fun_arity1   : MathQL.path -> string -> (MathQL.result -> MathQL.result) -> fun_spec

val fun_arity2   : MathQL.path -> string -> (MathQL.result ->  MathQL.result -> MathQL.result) -> fun_spec

val out_txt2     : std_text_out_spec -> 
                   string -> MathQL.query -> MathQL.query -> unit 

val out_txt_     : std_text_out_spec -> 
                   MathQL.path -> MathQL.query list -> unit 

val out_txt_full : std_text_out_spec -> 
                   MathQL.path -> MathQL.path list -> MathQL.query list -> unit 

(* generator registration ***************************************************)

type gen_spec = {arity : arity_t;
                 code  : eval_spec ->  MathQL.query list ->  MathQL.query
                }

val gen_register : MathQL.path -> gen_spec -> unit