It's exactly that (well, EitherT Error IO () perhaps) and the pattern would be far easier to replicate if Go had generics. So we're back here. Edit: I wrote an

It's exactly that (well, EitherT Error IO () perhaps) and the pattern would be far easier to replicate if Go had generics. So we're back here. Edit: I wrote an elaboration, https://news.ycombinator.com/item?id=8877732 https://news.ycombinator.com/item?id=8877732