> I am no Haskell buff, but I believe the common complaint is that "just need to mark your function as IO ()" has non-local effects, you end up needing to propa

> I am no Haskell buff, but I believe the common complaint is that "just need to mark your function as IO ()" has non-local effects, you end up needing to propagate a bunch of extra stuff everywhere. That's a feature. It forces you to separate pure functions from I/O. If you spend time thinking about how you (re)factor your work you can end up with most of the interesting logic being in pure functions that are then very easy to write tests for (because you don't have to mock network services, clocks, etc.), and all the interesting I/O logic gets segregated and made [hopefully] small.