[corank]

I think as long as the code sticks to the discipline of never actually doing I/O but only manipulating functions that perform them it would basically be doing the same thing as IO monads in Haskell.

So print(s) returns a function that when called prints s. Then there needs to be function that joins those functions, so print(a); print(b) evaluates to a function that once called prints out a and then b.

What makes Haskell special in my opinion is 1) it generalises this way of achieving "stateful" functions, 2) enforces such discipline for you and makes sure calling functions never produces side effects, and 3) some syntactic sugar (do, <-, etc) to make it easier to write this kind of code.

Also note that the above example only does output which would be the easier case. When it comes to code with input, there will suddenly be values which are unavailable until some side effects have been made, so the returned functions will also need to encode how those values are to be obtained and used, which complicates things further.