1.1 --- a/src/Pure/PIDE/document.scala	Mon May 24 23:01:51 2010 +0200
     1.2 +++ b/src/Pure/PIDE/document.scala	Mon May 24 23:19:40 2010 +0200
     1.3 @@ -7,6 +7,9 @@
     1.4  package isabelle
     1.5  
     1.6  
     1.7 +import scala.annotation.tailrec
     1.8 +
     1.9 +
    1.10  object Document
    1.11  {
    1.12    /* command start positions */
    1.13 @@ -80,7 +83,7 @@
    1.14  
    1.15      /* phase 2: recover command spans */
    1.16  
    1.17 -    def parse_spans(commands: Linear_Set[Command]): Linear_Set[Command] =
    1.18 +    @tailrec def parse_spans(commands: Linear_Set[Command]): Linear_Set[Command] =
    1.19      {
    1.20        commands.iterator.find(is_unparsed) match {
    1.21          case Some(first_unparsed) =>