+(* Copyright (C) 2004-2005, 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/
+ *)
+
+(* $Id$ *)
+
+open Printf
+
+type log_tag = [ `Debug | `Error | `Message | `Warning ]
+type log_callback = log_tag -> string -> unit
+
+(*
+colors=(black red green yellow blue magenta cyan gray white)
+ccodes=(30 31 32 33 34 35 36 37 39)
+*)
+
+let blue = "\e[0;34m"
+let yellow = "\e[0;33m"
+let green = "\e[0;32m"
+let red = "\e[0;31m"
+let black = "\e[0m"
+
+let default_callback tag s =
+ let prefix,ch =
+ match tag with
+ | `Message -> green ^ "Info: ", stdout
+ | `Warning -> yellow ^ "Warn: ", stderr
+ | `Error -> red ^ "Error: ", stderr
+ | `Debug -> blue ^ "Debug: ", stderr
+ in
+ output_string ch (prefix ^ black ^ s ^ "\n");
+ flush ch
+
+let callback = ref default_callback
+
+let set_log_callback f = callback := f
+let get_log_callback () = !callback
+
+let message s = !callback `Message s
+let warn s = !callback `Warning s
+let error s = !callback `Error s
+let debug s = !callback `Debug s
+