[thinkpad20]

A global counter is difficult because shared global mutable state should be difficult —- it can wreak havoc on your code. That said, if you’re really set on it it’s not particularly bad

    counter :: IORef Int
    counter = unsafePerformIO (newIORef 0)

    usesGlobalState :: IO ()
    usesGlobalState = do
      count <- readIORef counter
      putStrLn (“the counter was “ ++ show count)
      modifyIORef (+1) counter

It’s even easier in ocaml, where you’d use ref and not need to worry about the IO monad.

Anecdotally, I find it incredibly rare that such a thing is desirable, when you could instead create it in an IO monad and pass it through to functions that need it. But, it’s there when necessary. And making this kind of anti pattern hard is a strength of these languages, not a weakness.