Make "direct names" semantic

Author: odersky

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

@@ -248,6 +248,7 @@ object NameKinds {
   val ProtectedAccessorName = new PrefixNameKind(PROTECTEDACCESSOR, "protected$")
   val ProtectedSetterName = new PrefixNameKind(PROTECTEDSETTER, "protected$set") // dubious encoding, kept for Scala2 compatibility
   val AvoidClashName = new SuffixNameKind(AVOIDCLASH, "$_avoid_name_clash_$")
+  val DirectName = new SuffixNameKind(DIRECT, "$direct")
   val ModuleClassName = new SuffixNameKind(OBJECTCLASS, "$", optInfoString = "ModuleClass")
 
   object SignedName extends NameKind(63) {

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

@@ -143,8 +143,6 @@ object NameOps {
 
     def errorName: N = likeTyped(name ++ nme.ERROR)
 
-    def directName: N = likeTyped(name ++ DIRECT_SUFFIX)
-
     def freshened(implicit ctx: Context): N = likeTyped {
       name.toTermName match {
         case ModuleClassName(original) => ModuleClassName(original.freshened)

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

@@ -132,7 +132,6 @@ object StdNames {
     val COMPANION_MODULE_METHOD: N    = "companion$module"
     val COMPANION_CLASS_METHOD: N     = "companion$class"
     val TRAIT_SETTER_SEPARATOR: N     = str.TRAIT_SETTER_SEPARATOR
-    val DIRECT_SUFFIX: N              = "$direct"
 
     // value types (and AnyRef) are all used as terms as well
     // as (at least) arguments to the @specialize annotation.
@@ -166,7 +165,6 @@ object StdNames {
 
     // fictions we use as both types and terms
     final val ERROR: N    = "<error>"
-    final val ERRORenc: N = encode("<error>")
     final val NO_NAME: N  = "<none>"  // formerly NOSYMBOL
     final val WILDCARD: N = "_"
 

compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala

@@ -234,9 +234,11 @@ object TastyFormat {
   final val INITIALIZER = 23
   final val SHADOWED = 24
   final val AVOIDCLASH = 27
+  final val DIRECT = 28
   final val OBJECTCLASS = 29
 
   final val SIGNED = 63
+  final val firstInternalTag = 64
 
   // AST tags
 

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

@@ -11,6 +11,7 @@ import core.Decorators._
 import core.StdNames.nme
 import core.Names._
 import core.NameOps._
+import core.NameKinds.DirectName
 import ast.Trees._
 import ast.tpd
 import collection.mutable
@@ -91,7 +92,7 @@ class ShortcutImplicits extends MiniPhase with IdentityDenotTransformer { thisTr
     /** A new `m$direct` method to accompany the given method `m` */
     private def newDirectMethod(sym: Symbol)(implicit ctx: Context): Symbol = {
       val direct = sym.copy(
-        name = sym.name.directName,
+        name = DirectName(sym.name.asTermName).asInstanceOf[sym.ThisName],
         flags = sym.flags | Synthetic,
         info = directInfo(sym.info))
       if (direct.allOverriddenSymbols.isEmpty) direct.resetFlag(Override)
@@ -103,7 +104,7 @@ class ShortcutImplicits extends MiniPhase with IdentityDenotTransformer { thisTr
      */
     private def directMethod(sym: Symbol)(implicit ctx: Context): Symbol =
       if (sym.owner.isClass) {
-        val direct = sym.owner.info.member(sym.name.directName)
+        val direct = sym.owner.info.member(DirectName(sym.name.asTermName))
           .suchThat(_.info matches directInfo(sym.info)).symbol
         if (direct.maybeOwner == sym.owner) direct
         else newDirectMethod(sym).enteredAfter(thisTransform)
@@ -121,7 +122,7 @@ class ShortcutImplicits extends MiniPhase with IdentityDenotTransformer { thisTr
           case TypeApply(fn, args) => cpy.TypeApply(tree)(directQual(fn), args)
           case Block(stats, expr)  => cpy.Block(tree)(stats, directQual(expr))
           case tree: RefTree =>
-            cpy.Ref(tree)(tree.name.directName)
+            cpy.Ref(tree)(DirectName(tree.name.asTermName))
               .withType(directMethod(tree.symbol).termRef)
         }
         directQual(tree.qualifier)