1 files changed, 4 insertions, 0 deletions
diff --git a/src/dotty/tools/dotc/core/Decorators.scala b/src/dotty/tools/dotc/core/Decorators.scala
index 031974dfd..094aa7b4a 100644
--- a/src/dotty/tools/dotc/core/Decorators.scala
+++ b/src/dotty/tools/dotc/core/Decorators.scala
@@ -70,6 +70,10 @@ object Decorators {
       }
   }
 
+  implicit class ListOfListDecorator[T](val xss: List[List[T]]) extends AnyVal {
+    def nestedMap[U](f: T => U): List[List[U]] = xss map (_ map f)
+  }
+
   implicit class TextToString(val text: Text) extends AnyVal {
     def show(implicit ctx: Context) = text.mkString(ctx.settings.pageWidth.value)
   }