Lazy entering of names with internal $'s in package scopes

Names with internal $'s are entered in package scopes only if

  - we look for a name with internal $'s.
  - we want to know all the members of a package scope

 This optimization seems to be fairly effective. The typical range
 of package scopes that need $-names is between 0 and 20%. The optimization
seems to improve execution time of all unit tests by about 3%.

Also. drop the inheritance from Iterable to Scope. The reason
is that we now need a context parameter for toList and
other Iterable operations which makes them impossible to
fit into the Iterable framework.

1 files changed, 11 insertions, 10 deletions

diff --git a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
index b8cd7bb18..5a277cacb 100644
--- a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -930,14 +930,15 @@ object SymDenotations {
       *  and which is also defined in the same scope and compilation unit.
       *  NoSymbol if this class does not exist.
       */
-    final def companionClass(implicit ctx: Context): Symbol = {
-      val companionMethod = info.decls.denotsNamed(nme.COMPANION_CLASS_METHOD, selectPrivate).first
-
-      if (companionMethod.exists)
-        companionMethod.info.resultType.classSymbol
-      else
-        NoSymbol
-    }
+    final def companionClass(implicit ctx: Context): Symbol =
+      if (is(Package)) NoSymbol
+      else {
+        val companionMethod = info.decls.denotsNamed(nme.COMPANION_CLASS_METHOD, selectPrivate).first
+        if (companionMethod.exists)
+          companionMethod.info.resultType.classSymbol
+        else
+          NoSymbol
+      }
 
     final def scalacLinkedClass(implicit ctx: Context): Symbol =
       if (this is ModuleClass) companionNamed(effectiveName.toTypeName)
@@ -1777,8 +1778,8 @@ object SymDenotations {
       def constrNamed(cname: TermName) = info.decls.denotsNamed(cname).last.symbol
         // denotsNamed returns Symbols in reverse order of occurrence
       if (this.is(ImplClass)) constrNamed(nme.TRAIT_CONSTRUCTOR) // ignore normal constructor
-      else
-        constrNamed(nme.CONSTRUCTOR).orElse(constrNamed(nme.TRAIT_CONSTRUCTOR))
+      else if (this.is(Package)) NoSymbol
+      else constrNamed(nme.CONSTRUCTOR).orElse(constrNamed(nme.TRAIT_CONSTRUCTOR))
     }
 
     /** The parameter accessors of this class. Term and type accessors,