Several fixes and refactorings for typechecking

1) Refactoring of package loaders that ensures that a package is always loaded before new members are entered. This led to a refactoring of sourceModule in completers into its own trait

2) Refactoring of optSelfType ot selfInfo. Class Infos may now have a reference to a symbol in their selfInfo field, instead of always a type, as it was before. This allows to introduce laziness for self type evaluation. Laziness is needed so that modules can be desugared and the desugared version be compiled without special tricks.

3) <init> and $init members are no longer inherited.

4) Refactoring of createSymbol and enterSym, so that creating symbols and entering them in a scope is decoupled.
    Renamed the driver operation form `enterSym(s)` to `index`.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/dotty/tools/dotc/printing/PlainPrinter.scala b/src/dotty/tools/dotc/printing/PlainPrinter.scala
index fe67f5b89..9e5786126 100644
--- a/src/dotty/tools/dotc/printing/PlainPrinter.scala
+++ b/src/dotty/tools/dotc/printing/PlainPrinter.scala
@@ -204,14 +204,14 @@ class PlainPrinter(_ctx: Context) extends Printer {
         else
           (if (lo == defn.NothingType) Text() else " >: " ~ toText(lo)) ~
             (if (hi == defn.AnyType) Text() else " <: " ~ toText(hi))
-      case ClassInfo(pre, cls, cparents, decls, optSelfType) =>
+      case tp @ ClassInfo(pre, cls, cparents, decls, selfInfo) =>
         val preText = toTextLocal(pre)
         val (tparams, otherDecls) = decls.toList partition treatAsTypeParam
         val tparamsText =
           if (tparams.isEmpty) Text() else ("[" ~ dclsText(tparams) ~ "]").close
         val selfText =
-          if (optSelfType.exists)
-            "this: " ~ atPrec(InfixPrec) { toText(optSelfType) } ~ " =>"
+          if (selfInfo ne NoType)
+            "this: " ~ atPrec(InfixPrec) { toText(tp.selfType) } ~ " =>"
           else Text()
         val parentsText = Text(cparents.map(p =>
           toTextLocal(reconstituteParent(cls, p))), " with ")