src/Pure/Syntax/simple_syntax.ML

--- a/src/Pure/Syntax/simple_syntax.ML	Tue Mar 29 20:52:19 2016 +0200
+++ b/src/Pure/Syntax/simple_syntax.ML	Tue Mar 29 20:53:52 2016 +0200
@@ -21,7 +21,7 @@
 
 fun read scan s =
   (case
-      Symbol_Pos.explode (s, Position.none) |>
+      Symbol_Pos.explode0 s |>
       Lexicon.tokenize lexicon false |>
       filter Lexicon.is_proper |>
       Scan.read Lexicon.stopper scan of