message: defaults break inference
diff: @@ -60,8 +60,8 @@ const adapter = (_: any) => {
  export function gen<
  Eff extends GenEffect<any, any, any>,
  REff extends _R<Eff>,
  - EEff extends _E<Eff> = never,
  - AEff = void
  + EEff extends _E<Eff>,
  + AEff
  >(
  f: (i: {
  <A>(_: Option<A>): GenEffect<unknown, NoSuchElementException, A>
  