purescript
Add `shuffle` function
I think there is not yet a shuffle function in a general purpose library (I did find one in quickcheck, but it uses the Gen monad). I'm thinking something like this:
shuffle :: Array a -> Effect (Array a)
Would it make sense to add it here? Would you like a PR (it might add some dependencies though, notably purescript-arrays)? I think a basic implementation using the Yates-Fisher algorithm in the ST monad would be the most performant.
I feel like it's probably out of scope for the library, partially because it's too specific - if we add this but you want to shuffle a List, then what? How about a NonEmptyArray and NonEmptyList, or maybe even a Foldable? etc.
My solution to this usually is to do something like:
shuffle :: ∀ a. Array a -> Effect (Array a)
shuffle xs = map fst <<< Array.sortWith snd <$> traverse (\x -> Tuple x <$> Random.random) xs
Obviously very inefficient compared to Fisher-Yates, but anecdotally I've not really encountered a situation where it was a problem yet.
