[cube2222]

As I said, in practice they're a worse either monad. With which I meant -> they were inspired by them, but lack the monad part and having the value with the error in one object interchangeably. It's the same treating errors as values though.

[leshow]

It's really just a worse Either type, if anything, there's nothing monad about it. Although it's sort of hard to be close to an Either without being an algebraic data type. But I see what you're trying to say.