src/Pure/General/output.scala

--- a/src/Pure/General/output.scala	Fri May 02 19:30:34 2014 +0200
+++ b/src/Pure/General/output.scala	Fri May 02 19:51:40 2014 +0200
@@ -1,7 +1,7 @@
 /*  Title:      Pure/General/output.ML
     Author:     Makarius
 
-Isabelle output channels: plain text without markup.
+Isabelle channels for diagnostic output.
 */
 
 package isabelle
@@ -12,6 +12,7 @@
   def warning_text(msg: String): String = cat_lines(split_lines(msg).map("### " + _))
   def error_text(msg: String): String = cat_lines(split_lines(msg).map("*** " + _))
 
+  def writeln(msg: String) { System.err.println(msg) }
   def warning(msg: String) { System.err.println(warning_text(msg)) }
   def error_message(msg: String) { System.err.println(error_text(msg)) }
 }