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.

4 files changed, 6 insertions, 9 deletions

diff --git a/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala b/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
index c302aa61b..7ad7fb348 100644
--- a/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
@@ -217,7 +217,7 @@ object ExplicitOuter {
   def outerAccessor(cls: ClassSymbol)(implicit ctx: Context): Symbol =
     if (cls.isStatic) NoSymbol // fast return to avoid scanning package decls
     else cls.info.member(outerAccName(cls)).suchThat(_ is OuterAccessor).symbol orElse
-      cls.info.decls.find(_ is OuterAccessor).getOrElse(NoSymbol)
+      cls.info.decls.find(_ is OuterAccessor)
 
   /** Class has an outer accessor. Can be called only after phase ExplicitOuter. */
   private def hasOuter(cls: ClassSymbol)(implicit ctx: Context): Boolean =
diff --git a/compiler/src/dotty/tools/dotc/transform/PrimitiveForwarders.scala b/compiler/src/dotty/tools/dotc/transform/PrimitiveForwarders.scala
index d752ce8e7..7c51ba593 100644
--- a/compiler/src/dotty/tools/dotc/transform/PrimitiveForwarders.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PrimitiveForwarders.scala
@@ -43,7 +43,7 @@ class PrimitiveForwarders extends MiniPhaseTransform with IdentityDenotTransform
     import ops._
 
     def methodPrimitiveForwarders: List[Tree] =
-      for (meth <- mixins.flatMap(_.info.decls.flatMap(needsPrimitiveForwarderTo)).distinct)
+      for (meth <- mixins.flatMap(_.info.decls.toList.flatMap(needsPrimitiveForwarderTo)).distinct)
         yield polyDefDef(implementation(meth.asTerm), forwarder(meth))
 
     cpy.Template(impl)(body = methodPrimitiveForwarders ::: impl.body)
diff --git a/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala b/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala
index 44c26ecd9..eb7773ef3 100644
--- a/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala
+++ b/compiler/src/dotty/tools/dotc/transform/TreeChecker.scala
@@ -391,11 +391,11 @@ class TreeChecker extends Phase with SymTransformer {
           !x.isCompanionMethod &&
           !x.isValueClassConvertMethod
 
-      val symbolsNotDefined = cls.classInfo.decls.toSet.filter(isNonMagicalMethod) -- impl.body.map(_.symbol) - constr.symbol
+      val symbolsNotDefined = cls.classInfo.decls.toList.toSet.filter(isNonMagicalMethod) -- impl.body.map(_.symbol) - constr.symbol
 
       assert(symbolsNotDefined.isEmpty,
           i" $cls tree does not define methods: ${symbolsNotDefined.toList}%, %\n" +
-          i"expected: ${cls.classInfo.decls.toSet.filter(isNonMagicalMethod).toList}%, %\n" +
+          i"expected: ${cls.classInfo.decls.toList.toSet.filter(isNonMagicalMethod)}%, %\n" +
           i"defined: ${impl.body.map(_.symbol)}%, %")
 
       super.typedClassDef(cdef, cls)
diff --git a/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala b/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala
index b398c2767..00d491486 100644
--- a/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ValueClasses.scala
@@ -28,13 +28,10 @@ object ValueClasses {
       !d.isSuperAccessor &&
       !d.is(Macro)
 
-  /** The member that of a derived value class that unboxes it. */
+  /** The member of a derived value class that unboxes it. */
   def valueClassUnbox(d: ClassDenotation)(implicit ctx: Context): Symbol =
     // (info.decl(nme.unbox)).orElse(...)      uncomment once we accept unbox methods
-    d.classInfo.decls
-      .find(d => d.isTerm && d.symbol.is(ParamAccessor))
-      .map(_.symbol)
-      .getOrElse(NoSymbol)
+    d.classInfo.decls.find(_.is(TermParamAccessor))
 
   /** For a value class `d`, this returns the synthetic cast from the underlying type to
    *  ErasedValueType defined in the companion module. This method is added to the module