Abstract type parameters out from type symbols

In the new hk scheme, a type parameter can be represented by a
refinement without a corresponding symbol. Therefore, we need
to disentangle the info inherent in a type parameter from the
contents of a type symbol. We achieve this by creating a common
super trait "MemerInfo" of Symbol and RefinedType.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/dotty/tools/dotc/core/Symbols.scala b/src/dotty/tools/dotc/core/Symbols.scala
index 1b605e24f..c7eb54812 100644
--- a/src/dotty/tools/dotc/core/Symbols.scala
+++ b/src/dotty/tools/dotc/core/Symbols.scala
@@ -367,7 +367,7 @@ object Symbols {
    *  @param coord  The coordinates of the symbol (a position or an index)
    *  @param id     A unique identifier of the symbol (unique per ContextBase)
    */
-  class Symbol private[Symbols] (val coord: Coord, val id: Int) extends DotClass with printing.Showable {
+  class Symbol private[Symbols] (val coord: Coord, val id: Int) extends DotClass with MemberBinding with printing.Showable {
 
     type ThisName <: Name
 
@@ -489,6 +489,13 @@ object Symbols {
      */
     def pos: Position = if (coord.isPosition) coord.toPosition else NoPosition
 
+    // MemberBinding methods
+    def isTypeParam(implicit ctx: Context) = denot.is(TypeParam)
+    def memberName(implicit ctx: Context): Name = name
+    def memberBounds(implicit ctx: Context) = denot.info.bounds
+    def memberBoundsAsSeenFrom(pre: Type)(implicit ctx: Context) = pre.memberInfo(this).bounds
+    def memberVariance(implicit ctx: Context) = denot.variance
+
 // -------- Printing --------------------------------------------------------
 
     /** The prefix string to be used when displaying this symbol without denotation */