Clean up code relating to interfaces.

Previous implementation was confused about the meaning of interface (with default methods
or without?).

Now instead of Interface/JavaInterface we have

    PureInterface   - all members are abstract methods
    NoInits         - all members are methods

1 files changed, 7 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/typer/Namer.scala b/src/dotty/tools/dotc/typer/Namer.scala
index 3a1f0a98b..e8bb1b9e7 100644
--- a/src/dotty/tools/dotc/typer/Namer.scala
+++ b/src/dotty/tools/dotc/typer/Namer.scala
@@ -492,6 +492,13 @@ class Namer { typer: Typer =>
 
       index(rest)(inClassContext(selfInfo))
       denot.info = ClassInfo(cls.owner.thisType, cls, parentRefs, decls, selfInfo)
+      if (cls is Trait) {
+        if (body forall isNoInitMember) {
+          cls.setFlag(NoInits)
+          if (body forall isPureInterfaceMember)
+            cls.setFlag(PureInterface)
+        }
+      }
     }
   }