+(* Copyright (C) 2005, 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/
+ *)
+
+(** {2 Marshalling with version/consistency checks} *)
+
+(** {3 File formats}
+ *
+ * Files saved/loaded by this module share a common format:
+ *
+ * | n | Field name | Field type | Description |
+ * +---+-------------+------------+---------------------------------------+
+ * | 1 | format | integer | hash value of the 'fmt' parameter |
+ * | 2 | version | integer | 'version' parameter |
+ * | 3 | format dsc | string | extended 'fmt' parameter |
+ * | 4 | version dsc | string | extended 'version' parameter |
+ * | 5 | checksum | integer | hash value of the _field_ below |
+ * | 6 | data | raw | ocaml marshalling of 'data' parameter |
+ *
+ *)
+
+exception Corrupt_file of string (** checksum mismatch, or file too short *)
+exception Format_mismatch of string
+exception Version_mismatch of string
+
+ (** Marhsal some data according to the file format above.
+ * @param fmt format name
+ * @param version version number
+ * @param fname file name to which marshal data
+ * @param data data to be marshalled on disk *)
+val save: fmt:string -> version:int -> fname:string -> 'a -> unit
+
+ (** parameters as above
+ * @raise Corrupt_file
+ * @raise Format_mismatch
+ * @raise Version_mismatch *)
+val load: fmt:string -> version:int -> fname:string -> 'a
+