Test cases for scala#480

Author: odersky

tests/pos/i480.scala

@@ -0,0 +1,4 @@
+object O {
+  val x: Function1[String, String] = a => a
+  val x2: Function1[String, String] = a => "1"
+}

tests/pos/i480a.scala

@@ -0,0 +1,62 @@
+package dotty.tools
+package dotc
+package core
+
+import Types._, Contexts._, Symbols._, Denotations._, SymDenotations._, StdNames._, Names._
+import Flags._, Scopes._, Decorators._, NameOps._, util.Positions._
+import pickling.UnPickler.ensureConstructor
+import scala.annotation.{ switch, meta }
+import scala.collection.{ mutable, immutable }
+import PartialFunction._
+import collection.mutable
+import scala.reflect.api.{ Universe => ApiUniverse }
+
+object Definitions {
+  val MaxFunctionArity, MaxTupleArity = 22
+}
+
+/** A class defining symbols and types of standard definitions */
+class Definitions {
+
+  /** The HigherKinded trait corresponding to symbols `boundSyms` (which are assumed
+   *  to be the type parameters of a higher-kided type). This is a class symbol that
+   *  would be generated by the following schema.
+   *
+   *      class LambdaXYZ extends Object with P1 with ... with Pn {
+   *        type v_1 $hk$Arg0; ...; type v_N $hk$ArgN;
+   *        type Apply
+   *      }
+   *
+   *  Here:
+   *
+   *   - v_i are the variances of the bound symbols (i.e. +, -, or empty).
+   *   - XYZ is a string of length N with one letter for each variant of a bound symbol,
+   *     using `P` (positive variance), `N` (negative variance), `I` (invariant).
+   *   - for each positive or negative variance v_i there is a parent trait Pj which
+   *     is the same as LambdaXYZ except that it has `I` in i-th position.
+   */
+  def lambdaTrait(vcs: List[Int]): ClassSymbol = {
+
+    val completer = new LazyType  {
+      def complete(denot: SymDenotation)(implicit ctx: Context): Unit = {
+//        val cls = denot.asClass.classSymbol
+//        val paramDecls = newScope
+//        for (i <- 0 until vcs.length)
+//          newTypeParam(cls, tpnme.lambdaArgName(i), varianceFlags(vcs(i)), paramDecls)
+//        newTypeField(cls, tpnme.Apply, Covariant, paramDecls)
+        val parentTraitRefs =
+          for (i <- 0 until vcs.length if vcs(i) != 0)
+          yield lambdaTrait(vcs.updated(i, 0)).typeRef
+//        denot.info = ClassInfo(
+//            ScalaPackageClass.thisType, cls, ObjectClass.typeRef :: parentTraitRefs.toList, paramDecls)
+      }
+    }
+
+//    val traitName = tpnme.lambdaTraitName(vcs)
+
+//    def createTrait = ???
+
+    ???
+
+  }
+}