Merge from the annots-normtrees branch.

now use compiler trees instead of reflect trees.
In many cases, annotations on types can be rewritten
instead of discarded as the types undergo various
operations.  Also, -Yself-in-annots has been added.

1 files changed, 30 insertions, 0 deletions

diff --git a/src/library/scala/TypeConstraint.scala b/src/library/scala/TypeConstraint.scala
new file mode 100644
index 0000000000..96347dc67f
--- /dev/null
+++ b/src/library/scala/TypeConstraint.scala
@@ -0,0 +1,30 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2006-2007, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+// $Id$
+
+
+package scala
+
+/** <p>
+ *    A marker for annotations that, when applied to a type,
+ *    should be treated as a constraint on the annotated type.
+ *    A proper constraint should restrict the type based only
+ *    on information mentioned within the type.  A Scala compiler
+ *    can use this assumption to rewrite the contents of the
+ *    constraint as necessary.  To contrast, a type annotation
+ *    whose meaning depends on the context where it is written
+ *    down is not a proper constrained type, and this marker
+ *    should not be applied.  A Scala compiler will drop such
+ *    annotations in cases where it would rewrite a type constraint.
+ *  </p>
+ *
+ *  @author  Lex Spoon
+ *  @version 1.1, 2007-11-5
+ */
+trait TypeConstraint extends Annotation