+(* 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/
+ *)
+
+open Printf
+
+exception Malformed_key of string
+exception Key_not_found of string
+exception Type_error of string * string * string (* expected type, value, msg *)
+exception Parse_error of string * int (* file, lineno *)
+exception Invalid_value of (string * string) * string (* key, value, descr *)
+
+exception Unescape_failure
+
+type validator_id = int
+
+let get_next_validator_id =
+ let next_id = ref 0 in
+ fun () ->
+ incr next_id;
+ !next_id
+
+let magic_size = 127
+let validators = Hashtbl.create magic_size
+let registry = Hashtbl.create magic_size
+
+let backup_registry () = Hashtbl.copy registry
+let restore_registry backup =
+ Hashtbl.clear registry;
+ Hashtbl.iter (fun key value -> Hashtbl.replace registry key value) backup
+
+let valid_key_rex_raw = "\\w+(\\.\\w+)*"
+let config_line_raw = sprintf "\\s*(%s)\\s*=\\s*\"(.*)\"\\s*" valid_key_rex_raw
+let comment_rex = Pcre.regexp "^\\s*(#|$)"
+let valid_key_rex = Pcre.regexp ("^" ^ valid_key_rex_raw ^ "$")
+let config_line_rex = Pcre.regexp ("^" ^ config_line_raw ^ "$")
+
+let is_comment s = Pcre.pmatch ~rex:comment_rex s
+
+let escape = String.escaped
+let unescape =
+ let lexer = lazy (Genlex.make_lexer []) in
+ fun s ->
+ let tok_stream = Lazy.force lexer (Stream.of_string ("\"" ^ s ^ "\"")) in
+ match Stream.peek tok_stream with
+ | Some (Genlex.String s) -> s
+ | _ -> raise Unescape_failure
+
+let key_is_valid key =
+ if not (Pcre.pmatch ~rex:valid_key_rex key) then
+ raise (Malformed_key key)
+
+let value_is_valid ~key ~value =
+ List.iter
+ (fun (validator, descr) ->
+ if not (validator value) then
+ raise (Invalid_value ((key, value), descr)))
+ (Hashtbl.find_all validators key)
+
+let set' registry ~key ~value =
+ key_is_valid key;
+ value_is_valid ~key ~value;
+ Hashtbl.replace registry key value
+
+let get key =
+ key_is_valid key;
+ try
+ Hashtbl.find registry key
+ with Not_found -> raise (Key_not_found key)
+
+let set = set' registry
+
+let string_list_of_string s =
+ (* trailing blanks are removed per default by Pcre.split *)
+ Pcre.split ~pat:"\\s+" (Pcre.replace ~pat:"^\\s+" s)
+let string_of_string_list l = String.concat " " l
+
+let mk_get_set type_name (from_string: string -> 'a) (to_string: 'a -> string) =
+ let getter key =
+ let value = get key in
+ try
+ from_string value
+ with exn ->
+ raise (Type_error (type_name, value, Printexc.to_string exn))
+ in
+ let setter ~key ~value = set ~key ~value:(to_string value) in
+ (getter, setter)
+
+let (get_int, set_int) = mk_get_set "int" int_of_string string_of_int
+let (get_float, set_float) = mk_get_set "float" float_of_string string_of_float
+let (get_string_list, set_string_list) =
+ mk_get_set "string list" string_list_of_string string_of_string_list
+
+let save_to fname =
+ let oc = open_out fname in
+ try
+ Hashtbl.iter
+ (fun key value ->
+ output_string oc (sprintf "%s = \"%s\"" key (escape value)))
+ registry;
+ close_out oc
+ with e ->
+ close_out oc;
+ raise e
+
+let load_from fname =
+ let backup = backup_registry () in
+ Hashtbl.clear registry;
+ let ic = open_in fname in
+ let lineno = ref 0 in
+ try
+ while true do
+ incr lineno;
+ let line = input_line ic in
+ if not (is_comment line) then
+ let subs = Pcre.extract ~rex:config_line_rex line in
+ let (key, value) = (subs.(1), unescape subs.(3)) in
+ set ~key ~value
+ done
+ with
+ | End_of_file -> close_in ic
+ | Malformed_key _ | Unescape_failure | Not_found ->
+ restore_registry backup;
+ raise (Parse_error (fname, !lineno))
+ | e ->
+ close_in ic;
+ restore_registry backup;
+ raise e
+
+let add_validator ~key ~validator ~descr =
+ let id = get_next_validator_id () in
+ Hashtbl.add validators key (validator, descr);
+ id
+
+(*
+ (* DEBUGGING *)
+let dump () = Hashtbl.iter (fun k v -> printf "%s = %s\n" k v) registry
+*)
+