> You can use undefined, the nearest equivalent to null in Haskell
I'm not sure you can say that. `undefined` is a case of `error`, so it will blow up any time it's encountered (it's often used to stub code) not just when you try to use it, it's closer to putting a `throw` than to putting a `null`.
I'm not sure you can say that. `undefined` is a case of `error`, so it will blow up any time it's encountered (it's often used to stub code) not just when you try to use it, it's closer to putting a `throw` than to putting a `null`.