@@ -152,8 +152,17 @@
 				newCtx.set(e.name, e.layer.empty ? lay : e.layer, ri);
 			return eval(e.expr, lay, newCtx, OverwriteCtx);
 		}
 	}
+
+	Value eval( Die e, Layer lay, Table ctx, bool overwriteCtx=CascadeCtx )
+	{
+		if( isMacroLayer(lay) )
+			return ast2table(e, (AST e){return eval(e,lay,ctx);});
+		if( isUserDefinedLayer(lay) )
+			return new UndefinedValue;
+		throw genex!RuntimeException(e.pos, "undefined case");
+	}
 
 private:
 	// little little bit incremental macro defining version.
 	// enables @macro foo(x)=... in ... foo ..., only at the top level of the
@@ -482,12 +491,20 @@
 unittest
 {
 	auto e = new Evaluator;
 	enrollRuntimeLibrary(e);
-	assert_nothrow( e.evalString(`case 1`) );
+	assert_throw!RuntimeException( e.evalString(`case 1`) );
 	assert_nothrow( e.evalString(`case 1 when 1: 2`) );
 
 	// this is a shorthand for
 	//   @macro x = fun(){} in @macro(x)
 	// so it is ok to fail, but it is really incovenient on REPL
 	assert_nothrow( e.evalString(`@macro x=fun(){}`) );
 }
+
+unittest
+{
+	auto e = new Evaluator;
+	enrollRuntimeLibrary(e);
+	assert_throw!RuntimeException( e.evalString(`...`) );
+	assert_eq( e.evalString(`@@foo(x){x}; @foo(...)`), new UndefinedValue );
+}