permuations in haskell

generate all permutations in haskell https://gist.github.com/evgenii-malov/620946be8db18c21cfd44b0f152fdeb4

k-permutations of n https://www.youtube.com/watch?v=U9FSaCNp__4&t=7s ... https://www.youtube.com/watch?v=iZYPnDD2suk