Selective.Select_from_monadmodule Monad : Preface_specs.MONADtype 'a t = 'a Monad.tThe type held by the Selective.
val select : ('a, 'b) Preface_core.Shims.Either.t t -> ('a -> 'b) t -> 'b tselect e f apply f if e is Left. It allow to skip effect using Right.