[crimsonalucard]

The execution of the main function has side effects. All io functions have side effects that are only observable by main. The print function itself is a side effect. Yes I'm talking about Haskell.

What the io monad does is force the user seperate pure functions and impure functions via type checking.

I think it's sort of incorrect to say Haskell is pure. It's more that only from a certain perspective Haskell is pure.