Convert underlying -> superType elsewhere in front end

Author: odersky

compiler/src/dotty/tools/dotc/core/CheckRealizable.scala

@@ -132,7 +132,7 @@ class CheckRealizable(using Context) {
     case tp: RefinedType => refinedNames(tp.parent) + tp.refinedName
     case tp: AndType => refinedNames(tp.tp1) ++ refinedNames(tp.tp2)
     case tp: OrType  => refinedNames(tp.tp1) ++ refinedNames(tp.tp2)
-    case tp: TypeProxy => refinedNames(tp.underlying)
+    case tp: TypeProxy => refinedNames(tp.superType)
     case _ => Set.empty
   }
 

compiler/src/dotty/tools/dotc/core/PatternTypeConstrainer.scala

@@ -234,7 +234,7 @@ trait PatternTypeConstrainer { self: TypeComparer =>
     def refinementIsInvariant(tp: Type): Boolean = tp match {
       case tp: SingletonType => true
       case tp: ClassInfo => tp.cls.is(Final) || tp.cls.is(Case)
-      case tp: TypeProxy => refinementIsInvariant(tp.underlying)
+      case tp: TypeProxy => refinementIsInvariant(tp.superType)
       case _ => false
     }
 

compiler/src/dotty/tools/dotc/core/TypeComparer.scala

@@ -1584,7 +1584,7 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
       case tp: RecType => fix(tp.parent).substRecThis(tp, anchor)
       case tp @ RefinedType(parent, rname, rinfo) => tp.derivedRefinedType(fix(parent), rname, rinfo)
       case tp: TypeParamRef => fixOrElse(bounds(tp).hi, tp)
-      case tp: TypeProxy => fixOrElse(tp.underlying, tp)
+      case tp: TypeProxy => fixOrElse(tp.superType, tp)
       case tp: AndType => tp.derivedAndType(fix(tp.tp1), fix(tp.tp2))
       case tp: OrType  => tp.derivedOrType (fix(tp.tp1), fix(tp.tp2))
       case tp => tp
@@ -1857,7 +1857,7 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
   final def ensureStableSingleton(tp: Type): SingletonType = tp.stripTypeVar match {
     case tp: SingletonType if tp.isStable => tp
     case tp: ValueType => SkolemType(tp)
-    case tp: TypeProxy => ensureStableSingleton(tp.underlying)
+    case tp: TypeProxy => ensureStableSingleton(tp.superType)
     case tp => assert(ctx.reporter.errorsReported); SkolemType(tp)
   }
 

compiler/src/dotty/tools/dotc/core/TypeEval.scala

@@ -18,7 +18,7 @@ object TypeEval:
           // final val one = 1
           // type Two = one.type + one.type
           // ```
-          case tp: TypeProxy if tp.underlying.isStable => tp.underlying.fixForEvaluation
+          case tp: TypeProxy if tp.underlying.isStable => tp.underlying.fixForEvaluation // todo: should this be superType
           case tp => tp
 
       def constValue(tp: Type): Option[Any] = tp.fixForEvaluation match

compiler/src/dotty/tools/dotc/interactive/Completion.scala

@@ -483,7 +483,7 @@ object Completion {
           val symbol = newSymbol(owner = NoSymbol, name, flags, info)
           val denot = SymDenotation(symbol, NoSymbol, name, flags, info)
           denot +: extractRefinements(parent)
-        case tp: TypeProxy => extractRefinements(tp.underlying)
+        case tp: TypeProxy => extractRefinements(tp.superType)
         case _ => List.empty
 
     /** @param site The type to inspect.