Backport "Add default arguments to derived refined type" to LTS

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

@@ -783,7 +783,7 @@ class CheckCaptures extends Recheck, SymTransformer:
               adaptTypeFun(actual, rinfo.resType, expected, covariant, insertBox,
                 ares1 =>
                   val rinfo1 = rinfo.derivedLambdaType(rinfo.paramNames, rinfo.paramInfos, ares1)
-                  val actual1 = actual.derivedRefinedType(actual.parent, actual.refinedName, rinfo1)
+                  val actual1 = actual.derivedRefinedType(refinedInfo = rinfo1)
                   actual1
               )
             case _ =>

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

@@ -681,7 +681,7 @@ trait ConstraintHandling {
     case tp: AndType =>
       tp.derivedAndType(tp.tp1.hardenUnions, tp.tp2.hardenUnions)
     case tp: RefinedType =>
-      tp.derivedRefinedType(tp.parent.hardenUnions, tp.refinedName, tp.refinedInfo)
+      tp.derivedRefinedType(parent = tp.parent.hardenUnions)
     case tp: RecType =>
       tp.rebind(tp.parent.hardenUnions)
     case tp: HKTypeLambda =>

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

@@ -1731,7 +1731,7 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
   private def fixRecs(anchor: SingletonType, tp: Type): Type = {
     def fix(tp: Type): Type = tp.stripTypeVar match {
       case tp: RecType => fix(tp.parent).substRecThis(tp, anchor)
-      case tp @ RefinedType(parent, rname, rinfo) => tp.derivedRefinedType(fix(parent), rname, rinfo)
+      case tp: RefinedType => tp.derivedRefinedType(parent = fix(tp.parent))
       case tp: TypeParamRef => fixOrElse(bounds(tp).hi, tp)
       case tp: TypeProxy => fixOrElse(tp.superType, tp)
       case tp: AndType => tp.derivedAndType(fix(tp.tp1), fix(tp.tp2))

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

@@ -1328,7 +1328,7 @@ object Types {
       case tp: AndType =>
         tp.derivedAndType(tp.tp1.widenUnionWithoutNull, tp.tp2.widenUnionWithoutNull)
       case tp: RefinedType =>
-        tp.derivedRefinedType(tp.parent.widenUnion, tp.refinedName, tp.refinedInfo)
+        tp.derivedRefinedType(parent = tp.parent.widenUnion)
       case tp: RecType =>
         tp.rebind(tp.parent.widenUnion)
       case tp: HKTypeLambda =>
@@ -3152,7 +3152,9 @@ object Types {
 
     def checkInst(using Context): this.type = this // debug hook
 
-    def derivedRefinedType(parent: Type, refinedName: Name, refinedInfo: Type)(using Context): Type =
+    final def derivedRefinedType
+        (parent: Type = this.parent, refinedName: Name = this.refinedName, refinedInfo: Type = this.refinedInfo)
+        (using Context): Type =
       if ((parent eq this.parent) && (refinedName eq this.refinedName) && (refinedInfo eq this.refinedInfo)) this
       else RefinedType(parent, refinedName, refinedInfo)
 
@@ -4056,7 +4058,7 @@ object Types {
         case tp @ AppliedType(tycon, args) if defn.isFunctionNType(tp) =>
           wrapConvertible(tp.derivedAppliedType(tycon, args.init :+ addInto(args.last)))
         case tp @ defn.RefinedFunctionOf(rinfo) =>
-          wrapConvertible(tp.derivedRefinedType(tp.parent, tp.refinedName, addInto(rinfo)))
+          wrapConvertible(tp.derivedRefinedType(refinedInfo = addInto(rinfo)))
         case tp: MethodOrPoly =>
           tp.derivedLambdaType(resType = addInto(tp.resType))
         case ExprType(resType) =>

compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala

@@ -730,8 +730,8 @@ class Scala2Unpickler(bytes: Array[Byte], classRoot: ClassDenotation, moduleClas
             val info1 = info.symbol.info
             assert(info1.derivesFrom(defn.SingletonClass))
             RefinedType(parent1, name, info1.mapReduceAnd(removeSingleton)(_ & _))
-          case info =>
-            tp.derivedRefinedType(parent1, name, info)
+          case _ =>
+            tp.derivedRefinedType(parent = parent1)
         }
       case tp @ AppliedType(tycon, args) =>
         val tycon1 = tycon.safeDealias

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -1077,7 +1077,7 @@ trait Checking {
       case tp @ AppliedType(tycon, args) =>
         tp.derivedAppliedType(tycon, args.mapConserve(checkGoodBounds))
       case tp: RefinedType =>
-        tp.derivedRefinedType(tp.parent, tp.refinedName, checkGoodBounds(tp.refinedInfo))
+        tp.derivedRefinedType(refinedInfo = checkGoodBounds(tp.refinedInfo))
       case _ =>
         tp
     }

compiler/src/dotty/tools/dotc/typer/Inferencing.scala

@@ -537,7 +537,7 @@ object Inferencing {
       }
       if tparams.isEmpty then tp else tp.derivedAppliedType(tycon, args1)
     case tp: AndOrType => tp.derivedAndOrType(captureWildcards(tp.tp1), captureWildcards(tp.tp2))
-    case tp: RefinedType => tp.derivedRefinedType(captureWildcards(tp.parent), tp.refinedName, tp.refinedInfo)
+    case tp: RefinedType => tp.derivedRefinedType(parent = captureWildcards(tp.parent))
     case tp: RecType => tp.derivedRecType(captureWildcards(tp.parent))
     case tp: LazyRef => captureWildcards(tp.ref)
     case tp: AnnotatedType => tp.derivedAnnotatedType(captureWildcards(tp.parent), tp.annot)

compiler/src/dotty/tools/dotc/typer/Synthesizer.scala

@@ -727,8 +727,8 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
     def recur(handlers: SpecialHandlers): TreeWithErrors = handlers match
       case (cls, handler) :: rest =>
         def baseWithRefinements(tp: Type): Type = tp.dealias match
-          case tp @ RefinedType(parent, rname, rinfo) =>
-            tp.derivedRefinedType(baseWithRefinements(parent), rname, rinfo)
+          case tp: RefinedType =>
+            tp.derivedRefinedType(parent = baseWithRefinements(tp.parent))
           case _ =>
             tp.baseType(cls)
         val base = baseWithRefinements(formal)