Replace hasHigherKind by hasSimpleKind

hasHigherKind is misleading since it will cover AnyKind and Effect as
well and it is not clear how these are "higher" kinds.

Author: odersky

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

@@ -210,12 +210,9 @@ class TypeApplications(val self: Type) extends AnyVal {
   /** Is self type bounded by a type lambda or AnyKind? */
   def isLambdaSub(implicit ctx: Context): Boolean = hkResult.exists
 
-  /** Is self type of kind != "*"? */
-  def hasHigherKind(implicit ctx: Context): Boolean =
-    typeParams.nonEmpty || self.hasAnyKind
-
   /** Is self type of kind "*"? */
-  def hasFirstKind(implicit ctx: Context): Boolean = !hasHigherKind
+  def hasSimpleKind(implicit ctx: Context): Boolean =
+    typeParams.isEmpty && !self.hasAnyKind
 
   /** If self type is higher-kinded, its result type, otherwise NoType.
    *  Note: The hkResult of an any-kinded type is again AnyKind.

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

@@ -46,12 +46,8 @@ object Checking {
    */
   def checkBounds(args: List[tpd.Tree], boundss: List[TypeBounds], instantiate: (Type, List[Type]) => Type)(implicit ctx: Context): Unit = {
     (args, boundss).zipped.foreach { (arg, bound) =>
-      if (!bound.isLambdaSub && arg.tpe.hasHigherKind) {
+      if (!bound.isLambdaSub && !arg.tpe.hasSimpleKind) {
         // see MissingTypeParameterFor
-        if (!arg.tpe.isLambdaSub) { // FIXME: Provisional, remove
-          println(i"different for checkBounds $arg vs $bound at ${ctx.phase} in ${ctx.owner.ownersIterator.toList}")
-          throw new AssertionError("")
-        }
         ctx.error(ex"missing type parameter(s) for $arg", arg.pos)
       }
     }
@@ -709,7 +705,7 @@ trait Checking {
 
   /** Check that `tpt` does not define a higher-kinded type */
   def checkSimpleKinded(tpt: Tree)(implicit ctx: Context): Tree =
-    if (tpt.tpe.hasHigherKind && !ctx.compilationUnit.isJava) {
+    if (!tpt.tpe.hasSimpleKind && !ctx.compilationUnit.isJava) {
         // be more lenient with missing type params in Java,
         // needed to make pos/java-interop/t1196 work.
       errorTree(tpt, MissingTypeParameterFor(tpt.tpe))

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

@@ -255,7 +255,7 @@ trait TypeAssigner {
    */
   def accessibleSelectionType(tree: untpd.RefTree, qual1: Tree)(implicit ctx: Context): Type = {
     var qualType = qual1.tpe.widenIfUnstable
-    if (qualType.hasHigherKind && tree.name != nme.CONSTRUCTOR)
+    if (!qualType.hasSimpleKind && tree.name != nme.CONSTRUCTOR)
       // constructors are selected on typeconstructor, type arguments are passed afterwards
       qualType = errorType(em"$qualType takes type parameters", qual1.pos)
     else if (!qualType.isInstanceOf[TermType]) qualType = errorType(em"$qualType is illegal as a selection prefix", qual1.pos)