src/Tools/VSCode/src/document_model.scala

--- a/src/Tools/VSCode/src/document_model.scala	Wed Dec 28 16:45:00 2016 +0100
+++ b/src/Tools/VSCode/src/document_model.scala	Wed Dec 28 16:50:14 2016 +0100
@@ -17,6 +17,9 @@
   changed: Boolean = true,
   published_diagnostics: List[Text.Info[Command.Results]] = Nil)
 {
+  override def toString: String = node_name.toString
+
+
   /* header */
 
   def is_theory: Boolean = node_name.is_theory