src/Pure/PIDE/command.scala

--- a/src/Pure/PIDE/command.scala	Mon Aug 22 21:09:26 2011 +0200
+++ b/src/Pure/PIDE/command.scala	Mon Aug 22 21:42:02 2011 +0200
@@ -84,6 +84,11 @@
 
   def span(toks: List[Token]): Command =
     new Command(Document.no_id, toks)
+
+
+  /* perspective */
+
+  type Perspective = List[Command]  // visible commands in canonical order
 }