5 files changed, 11 insertions, 5 deletions
diff --git a/src/dotty/tools/dotc/typer/Applications.scala b/src/dotty/tools/dotc/typer/Applications.scala
index 860a7be80..9efa7d49e 100644
--- a/src/dotty/tools/dotc/typer/Applications.scala
+++ b/src/dotty/tools/dotc/typer/Applications.scala
@@ -360,7 +360,7 @@ trait Applications extends Compatibility { self: Typer =>
     init()
 
     def addArg(arg: Tree, formal: Type): Unit =
-      typedArgBuf += adaptInterpolated(arg, formal.widenByName)
+      typedArgBuf += adaptInterpolated(arg, formal.widenExpr)
 
     def makeVarArg(n: Int, elemFormal: Type): Unit = {
       val args = typedArgBuf.takeRight(n).toList
@@ -433,7 +433,7 @@ trait Applications extends Compatibility { self: Typer =>
   /** Subclass of Application for type checking an Apply node with untyped arguments. */
   class ApplyToUntyped(app: untpd.Apply, fun: Tree, methRef: TermRef, proto: FunProto, resultType: Type)(implicit ctx: Context)
   extends TypedApply(app, fun, methRef, proto.args, resultType) {
-    def typedArg(arg: untpd.Tree, formal: Type): TypedArg = proto.typedArg(arg, formal.widenByName)
+    def typedArg(arg: untpd.Tree, formal: Type): TypedArg = proto.typedArg(arg, formal.widenExpr)
     def treeToArg(arg: Tree): untpd.Tree = untpd.TypedSplice(arg)
   }
 
diff --git a/src/dotty/tools/dotc/typer/EtaExpansion.scala b/src/dotty/tools/dotc/typer/EtaExpansion.scala
index 782e5382f..16a02ba5c 100644
--- a/src/dotty/tools/dotc/typer/EtaExpansion.scala
+++ b/src/dotty/tools/dotc/typer/EtaExpansion.scala
@@ -58,7 +58,7 @@ object EtaExpansion {
     methType match {
       case MethodType(paramNames, paramTypes) =>
         (args, paramNames, paramTypes).zipped map { (arg, name, tp) =>
-          if (tp isRef defn.ByNameParamClass) arg
+          if (tp.isInstanceOf[ExprType]) arg
           else liftArg(defs, arg, if (name contains '$') "" else name.toString + "$")
         }
       case _ =>
diff --git a/src/dotty/tools/dotc/typer/Implicits.scala b/src/dotty/tools/dotc/typer/Implicits.scala
index b32535167..3878e5235 100644
--- a/src/dotty/tools/dotc/typer/Implicits.scala
+++ b/src/dotty/tools/dotc/typer/Implicits.scala
@@ -263,7 +263,7 @@ trait Implicits { self: Typer =>
    */
   def inferImplicit(pt: Type, argument: Tree, pos: Position)(implicit ctx: Context): SearchResult = track("inferImplicit") {
     ctx.traceIndented(s"search implicit ${pt.show}, arg = ${argument.show}: ${argument.tpe.show}", show = true) {
-      assert(!(pt isRef defn.ByNameParamClass))
+      assert(!pt.isInstanceOf[ExprType])
       val isearch =
         if (ctx.settings.explaintypes.value) new ExplainedImplicitSearch(pt, argument, pos)
         else new ImplicitSearch(pt, argument, pos)
diff --git a/src/dotty/tools/dotc/typer/Inferencing.scala b/src/dotty/tools/dotc/typer/Inferencing.scala
index 81e03f696..c306b07f3 100644
--- a/src/dotty/tools/dotc/typer/Inferencing.scala
+++ b/src/dotty/tools/dotc/typer/Inferencing.scala
@@ -30,7 +30,7 @@ object Inferencing {
      *    3. there is an implicit conversion from `tp` to `pt`.
      */
     def isCompatible(tp: Type, pt: Type)(implicit ctx: Context): Boolean =
-      tp.widenByName <:< pt.widenByName || viewExists(tp, pt)
+      tp.widenExpr <:< pt.widenExpr || viewExists(tp, pt)
 
     /** Test compatibility after normalization in a fresh typerstate. */
     def normalizedCompatible(tp: Type, pt: Type)(implicit ctx: Context) = {
diff --git a/src/dotty/tools/dotc/typer/Typer.scala b/src/dotty/tools/dotc/typer/Typer.scala
index 54a299291..99d5f6b98 100644
--- a/src/dotty/tools/dotc/typer/Typer.scala
+++ b/src/dotty/tools/dotc/typer/Typer.scala
@@ -707,6 +707,11 @@ class Typer extends Namer with Applications with Implicits {
     cpy.AppliedTypeTree(tree, tpt1, args1) withType tpt1.tpe.appliedTo(args1.tpes)
   }
 
+  def typedByNameTypeTree(tree: untpd.ByNameTypeTree)(implicit ctx: Context): ByNameTypeTree = track("typedByNameTypeTree") {
+    val result1 = typed(tree.result)
+    cpy.ByNameTypeTree(tree, result1) withType ExprType(result1.tpe)
+  }
+
   def typedTypeBoundsTree(tree: untpd.TypeBoundsTree)(implicit ctx: Context): TypeBoundsTree = track("typedTypeBoundsTree") {
     val TypeBoundsTree(lo, hi) = desugar.typeBoundsTree(tree)
     val lo1 = typed(lo)
@@ -875,6 +880,7 @@ class Typer extends Namer with Applications with Implicits {
           case tree: untpd.OrTypeTree => typedOrTypeTree(tree)
           case tree: untpd.RefinedTypeTree => typedRefinedTypeTree(tree)
           case tree: untpd.AppliedTypeTree => typedAppliedTypeTree(tree)
+          case tree: untpd.ByNameTypeTree => typedByNameTypeTree(tree)
           case tree: untpd.TypeBoundsTree => typedTypeBoundsTree(tree)
           case tree: untpd.Alternative => typedAlternative(tree, pt)
           case tree: untpd.Import => typedImport(tree, sym)