import scala.tools.nsc.reporters._ import scala.tools.nsc.Settings import reflect.runtime.Mirror.ToolBox object Test extends App { def foo[T](ys: List[T]): Int => Int = { val fun = reflect.Code.lift{(x: Int) => { x }} val reporter = new ConsoleReporter(new Settings) val toolbox = new ToolBox(reporter) val dyn = toolbox.runExpr(fun.tree) dyn.asInstanceOf[Int => Int] } println(foo(List(1, 2, 3))(10)) println(foo(List(1, 2, 3, 4))(10)) }