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[helm.git] / components / extlib / hLog.ml

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+(* 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
+