Tweak other occurrences of isNamedTuple

Author: odersky

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

@@ -543,7 +543,7 @@ object Completion:
             .groupByName
 
       val qualTpe = qual.typeOpt
-      if qualTpe.isNamedTupleType then
+      if qualTpe.derivesFromNamedTuple then
         namedTupleCompletionsFromType(qualTpe)
       else if qualTpe.derivesFrom(defn.SelectableClass) then
         val pre = if !TypeOps.isLegalPrefix(qualTpe) then Types.SkolemType(qualTpe) else qualTpe

compiler/src/dotty/tools/dotc/transform/PatternMatcher.scala

@@ -107,7 +107,7 @@ object PatternMatcher {
         // TODO: Drop Case once we use everywhere else `isPatmatGenerated`.
 
     private def dropNamedTuple(tree: Tree): Tree =
-      val tpe = tree.tpe.widen
+      val tpe = tree.tpe.widenDealias
       if tpe.isNamedTupleType then tree.cast(tpe.stripNamedTuple) else tree
 
     /** The plan `let x = rhs in body(x)` where `x` is a fresh variable */

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

@@ -876,7 +876,7 @@ trait Implicits:
        || inferView(dummyTreeOfType(from), to)
             (using ctx.fresh.addMode(Mode.ImplicitExploration).setExploreTyperState()).isSuccess
           // TODO: investigate why we can't TyperState#test here
-       || from.widen.isNamedTupleType && to.derivesFrom(defn.TupleClass)
+       || from.widen.derivesFromNamedTuple && to.derivesFrom(defn.TupleClass)
            && from.widen.stripNamedTuple <:< to
        )
 

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

@@ -2706,7 +2706,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
             body1.isInstanceOf[RefTree] && !isWildcardArg(body1)
             || body1.isInstanceOf[Literal]
           val symTp =
-            if isStableIdentifierOrLiteral || pt.isNamedTupleType then pt
+            if isStableIdentifierOrLiteral || pt.dealias.isNamedTupleType then pt
               // need to combine tuple element types with expected named type
             else if isWildcardStarArg(body1)
                     || pt == defn.ImplicitScrutineeTypeRef