Reject ranges that start beyond last item

2014-09-07 12:47:07 -07:00
parent db7ccda74d
commit fcdc37d20b
4 changed files with 33 additions and 13 deletions
@@ -49,4 +49,4 @@ offset :: NonnegRange -> Int
 offset range =
  case rangeLower range
    of BoundaryBelow from -> from
-       _ -> 0 -- should never happen
+       _ -> error "range without lower bound" -- should never happen