until -package:numeric-prelude -package:llvm-hs-pure -package:snap-core -package:extra -is:exact -package:utility-ht package:selective

untilRight :: (Monoid a, Selective f) => f (Either a b) -> f (a, b)
selective Control.Selective
Keep running an effectful computation until it returns a Right value, collecting the Left's using a supplied Monoid instance.