Hey thanks for clarifying -- Maybe I've just been a victim too long, but those actually don't seem like distinct ways. As far as why you can throw an exception

Hey thanks for clarifying -- Maybe I've just been a victim too long, but those actually don't seem like distinct ways. As far as why you can throw an exception in pure code but only catch it in monad, much ink has been spilled[0]. I won't claim to completely understand the reasoning in that SO post and the linked paper[1], but the reasons for this dichotomy seem to be clear. 2) -> 5) are not ways of handling errors though, they're ways of characterizing/combining monadic computations that CAN error, IMO. In the end, it's still the errors-as-values (`Either SomeException value`) concept, but in combined with the fact that your computation is in a monadic context. Also, maybe I've just been brainwashed by myself to think that way after doing Haskell for this short amount of time. In practice, how I throw an error from a monadic computation (I generally have never done it from pure code) has been pretty well-defined, I haven't had to go down this particular rabit hole much at all -- ExceptT is what I've used the most (I've done most of my work with Servant[2]). Honestly what I've had problems the most with from my haskell code was dealing with the database or mail servers and tcp sockets and stuff -- stuff that failed at runtime because I put in some bad code Haskell couldn't check before runtime. That said, monads & monad transformers are indeed a complex concept, and are very confusing to beginners (I'm still not 100% confident in my knowledge of them), so this is definitely a point against Haskell. And of course your earlier point about unsafe functions in the std lib is as valid as ever. [0]: https://stackoverflow.com/questions/12335245/why-is-catching-an-exception-non-pure-but-throwing-an-exception-is-pure#12345665 https://stackoverflow.com/questions/12335245/why-is-catching... [1]: https://www.microsoft.com/en-us/research/publication/tackling-awkward-squad-monadic-inputoutput-concurrency-exceptions-foreign-language-calls-haskell/?from=http%3A%2F%2Fresearch.microsoft.com%2Fen-us%2Fum%2Fpeople%2Fsimonpj%2Fpapers%2Fmarktoberdorf%2F https://www.microsoft.com/en-us/research/publication/tacklin... [2]: https://haskell-servant.readthedocs.io/ https://haskell-servant.readthedocs.io/