In many discussions about FP - especially about purely functional programming - there are talks about IO monad, IO type and so on. Its users’ argument on how it is better than your standard imperative approach, how it helps reason, encapsulate side-effects and design more elegant programs. On the other hand, its opponents argue, that programs are side-effectful by nature, so you would end up with something that needs IO for like 80% of the codebase while learning curve for newcomers would g...
