Drop RefiningVar

Author: odersky

compiler/src/dotty/tools/dotc/cc/CaptureSet.scala

@@ -395,13 +395,6 @@ object CaptureSet:
   def apply(elems: Refs)(using Context): CaptureSet.Const =
     if elems.isEmpty then empty else Const(elems)
 
-  /** If this context property is asserted, we conflate capture roots in subCapture
-   *  tests. Specifically, `cap` then subsumes everything and all local roots subsume `cap`.
-   *  This generally not sound. We currently use loose root checking only in self type
-   *  conformance tests in CheckCaptures.checkSelfTypes.
-   */
-  val LooseRootChecking: Property.Key[Unit] = Property.Key()
-
   /** The subclass of constant capture sets with given elements `elems` */
   class Const private[CaptureSet] (val elems: Refs, val description: String = "") extends CaptureSet:
     def isConst = true
@@ -618,14 +611,6 @@ object CaptureSet:
     override def toString = s"Var$id$elems"
   end Var
 
-  /** A variable used in refinements of class parameters. See `addCaptureRefinements`.
-   */
-  class RefiningVar(owner: Symbol, val getter: Symbol)(using @constructorOnly ictx: Context) extends Var(owner):
-    description = i"of parameter ${getter.name} of ${getter.owner}"
-    override def optionalInfo(using Context): String =
-      super.optionalInfo + (
-        if ctx.settings.YprintDebug.value then "(refining)" else "")
-
   /** A variable that is derived from some other variable via a map or filter. */
   abstract class DerivedVar(owner: Symbol, initialElems: Refs)(using @constructorOnly ctx: Context)
   extends Var(owner, initialElems):
@@ -1006,8 +991,6 @@ object CaptureSet:
           if tp.typeSymbol == defn.Caps_Cap then universal else empty
         case _: TypeParamRef =>
           empty
-        case CapturingType(parent, refs: RefiningVar) =>
-          refs
         case CapturingType(parent, refs) =>
           recur(parent) ++ refs
         case tpd @ defn.RefinedFunctionOf(rinfo: MethodType) if followResult =>

compiler/src/dotty/tools/dotc/cc/Setup.scala

@@ -175,7 +175,7 @@ class Setup extends PreRecheck, SymTransformer, SetupAPI:
                   val getterType =
                     mapInferred(refine = false)(tp.memberInfo(getter)).strippedDealias
                   RefinedType(core, getter.name,
-                      CapturingType(getterType, CaptureSet.RefiningVar(NoSymbol, getter)))
+                      CapturingType(getterType, CaptureSet.Var(ctx.owner)))
                     .showing(i"add capture refinement $tp --> $result", ccSetup)
                 else
                   core

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

@@ -682,18 +682,6 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
                   case tp1: RefinedType =>
                     return isSubInfo(tp1.refinedInfo, tp2.refinedInfo)
                   case _ =>
-            else tp2.refinedInfo match
-              case rinfo2 @ CapturingType(_, refs: CaptureSet.RefiningVar) =>
-                tp1.widen match
-                  case RefinedType(parent1, tp2.refinedName, rinfo1) =>
-                    // When comparing against a Var in class instance refinement,
-                    // take the Var as the precise truth, don't also look in the parent.
-                    // The parent might have a capture root at the wrong level.
-                    // TODO: Generalize this to other refinement situations where the
-                    // lower type's refinement appears elsewhere?
-                    return isSubType(rinfo1, rinfo2) && recur(parent1, tp2.parent)
-                  case _ =>
-              case _ =>
           end if
 
           val skipped2 = skipMatching(tp1w, tp2)

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

@@ -834,26 +834,19 @@ object Types {
               pinfo recoverable_& rinfo
           pdenot.asSingleDenotation.derivedSingleDenotation(pdenot.symbol, jointInfo)
         }
-        else rinfo match
-          case CapturingType(_, cs: CaptureSet.RefiningVar) =>
-            // If `rinfo` is a capturing type added by `addCaptureRefinements` it
-            // already contains everything there is to know about the member type.
-            // On the other hand, the member in parent might belong to an outer nesting level,
-            // which should be ignored at the point where instances of the class are constructed.
-            pdenot.asSingleDenotation.derivedSingleDenotation(pdenot.symbol, rinfo)
-          case _ =>
-            val isRefinedMethod = rinfo.isInstanceOf[MethodOrPoly]
-            val joint = pdenot.meet(
-              new JointRefDenotation(NoSymbol, rinfo, Period.allInRun(ctx.runId), pre, isRefinedMethod),
-              pre,
-              safeIntersection = ctx.base.pendingMemberSearches.contains(name))
-            joint match
-              case joint: SingleDenotation
-              if isRefinedMethod && rinfo <:< joint.info =>
-                // use `rinfo` to keep the right parameter names for named args. See i8516.scala.
-                joint.derivedSingleDenotation(joint.symbol, rinfo, pre, isRefinedMethod)
-              case _ =>
-                joint
+        else
+          val isRefinedMethod = rinfo.isInstanceOf[MethodOrPoly]
+          val joint = pdenot.meet(
+            new JointRefDenotation(NoSymbol, rinfo, Period.allInRun(ctx.runId), pre, isRefinedMethod),
+            pre,
+            safeIntersection = ctx.base.pendingMemberSearches.contains(name))
+          joint match
+            case joint: SingleDenotation
+            if isRefinedMethod && rinfo <:< joint.info =>
+              // use `rinfo` to keep the right parameter names for named args. See i8516.scala.
+              joint.derivedSingleDenotation(joint.symbol, rinfo, pre, isRefinedMethod)
+            case _ =>
+              joint
       }
 
       def goApplied(tp: AppliedType, tycon: HKTypeLambda) =