WIP fixing subsumes

Author: noti0na1

Diff for: compiler/src/dotty/tools/dotc/cc/CaptureRef.scala

@@ -100,8 +100,9 @@ trait CaptureRef extends TypeProxy, ValueType:
    *   x: x1.type /\ x1 subsumes y  ==>  x subsumes y
    *   TODO: Document path cases
    */
-  final def subsumes(y: CaptureRef)(using Context): Boolean =
-    
+  // import reporting.trace
+  final def subsumes(y: CaptureRef)(using Context): Boolean = // trace.force(i"subsumes $this, $y"):
+
     def subsumingRefs(x: Type, y: Type): Boolean = x match
       case x: CaptureRef => y match
         case y: CaptureRef => x.subsumes(y)
@@ -137,20 +138,26 @@ trait CaptureRef extends TypeProxy, ValueType:
         case MaybeCapability(y1) => this.stripMaybe.subsumes(y1)
         case y: TypeRef if y.symbol.info.derivesFrom(defn.Caps_CapSet) =>
           y.info match
-            case _: TypeAlias => y.captureSetOfInfo.elems.exists(this.subsumes)
+            case _: TypeAlias => y.captureSetOfInfo.elems.forall(this.subsumes)
             case TypeBounds(_, hi: CaptureRef) => this.subsumes(hi)
-            case _ => false
+            case _ => y.captureSetOfInfo.elems.forall(this.subsumes)
         case _ => false
     || this.match
         case ReachCapability(x1) => x1.subsumes(y.stripReach)
         case x: TermRef => viaInfo(x.info)(subsumingRefs(_, y))
         case x: TermParamRef => subsumesExistentially(x, y)
-        case x: TypeRef if x.symbol.info.derivesFrom(defn.Caps_CapSet) =>
+        case x: TypeRef if x.derivesFrom(defn.Caps_CapSet) =>
           x.info match
-            case _: TypeAlias => x.captureSetOfInfo.elems.exists(_.subsumes(y))
-            case TypeBounds(lo: CaptureRef, _) => lo.subsumes(y)
-            case _ => false
+            case _: TypeAlias =>
+              x.captureSetOfInfo.elems.exists(_.subsumes(y))
+            case TypeBounds(lo: CaptureRef, _) =>
+              lo.subsumes(y)
+            case _ =>
+              x.captureSetOfInfo.elems.exists(_.subsumes(y))
         case x: TypeRef => assumedContainsOf(x).contains(y)
+        case AnnotatedType(parent, ann)
+        if ann.symbol.isRetains && parent.derivesFrom(defn.Caps_CapSet) =>
+          ann.tree.toCaptureSet.elems.exists(_.subsumes(y))
         case _ => false
   end subsumes