mkCounter :: String -> (Int -> Int) -> Effect (ReactComponent {})
    mkCounter label op = do
      component "Counter" \props -> React.do
        counter /\ setCounter <- useState 0

        pure
          $ R.button
            { onClick: handler_ do
                setCounter op
            , children:
                [ R.text $ label <> ": " <> show counter ]
            }

    mkCounter "Increment" (_ + 1)

Although I can read Purescript reasonably well I'm not so proficient writing it (I do most of my programming in a different FP language, so I understand the concepts but not the specifics.) I didn't attempt to modify the code I pulled from the example because it would take more time than I have to install Purescript and check my modifications.

It would be simple to add this functionality. This equivalent of the `counterType` would be an algebraic data type, defined looking something like

  data counterType = Increment | Decrement

  case counterType of
    Increment -> ... make increment here ...
    Decrement -> ... make decrement here ...

  (_ + 1)

  x => x + 1