[coolsunglasses]

ngrams from the book NLP for the Working Programmer:

    ngrams' :: Int -> [b] -> [[b]]
    ngrams' n = filter ((==) n . length) . map (take n) . tails

ghci session:

    λ> let ngrams' n = filter ((==) n . length) . map (take n) . tails

    λ> inputList
    ["all","this","happened","more","or","less"]

    λ> tails inputList
    [["all","this","happened","more","or","less"],["this","happened","more","or","less"],["happened","more","or","less"],["more","or","less"],["or","less"],["less"],[]]

    λ> map (take 2) (tails inputList)
    [["all","this"],["this","happened"],["happened","more"], ["more","or"],["or","less"],["less"],[]]

    λ> filter ((==) 2 . length) (map (take 2) (tails inputList))
    [["all","this"],["this","happened"],["happened","more"],["more","or"],["or","less"]]

Pointfree Haskell code oftens ends up being a lot like piping together Unix commands.

Except typed and pure. With global type inference, so you have an objective type in mind, you can slap together and query the type with :t in ghci and see if it looks like what you wanted.