diff -r 25045094d7bb -r 134ae7da2ccf src/Pure/PIDE/text.scala
--- a/src/Pure/PIDE/text.scala	Sat Dec 10 17:20:39 2016 +0100
+++ b/src/Pure/PIDE/text.scala	Sat Dec 10 17:22:47 2016 +0100
@@ -37,9 +37,9 @@
   {
     // denotation: {start} Un {i. start < i & i < stop}
     if (start > stop)
-      error("Bad range: [" + start.toString + ":" + stop.toString + "]")
+      error("Bad range: [" + start.toString + ".." + stop.toString + "]")
 
-    override def toString: String = "[" + start.toString + ":" + stop.toString + "]"
+    override def toString: String = "[" + start.toString + ".." + stop.toString + "]"
 
     def length: Int = stop - start