Generating a sublist from cycle in Haskell

Question

Let's say I have a list of twelve musical notes (which have their own data type), and I want a function that returns a list of notes starting with a given note and looping around.

data Note = C | CsDb | D | DsEb | E | F | FsGb | G | GsAb | A | AsBb | B deriving (Read, Eq, Ord, Enum, Bounded)
getNotes :: Note -> [Note]
getNotes root = take 12 $ doSomething root $ cycle noteList
    where noteList :: [Note]
          noteList = [minBound..maxBound]

such that

ghci> getNotes E
[E, F, FsGb, G, GsAb, A, AsBb, B, C, CsDb, D, DsEb] 

I can think of a few sloppy ways to do this, but it feels like there should be an obvious, very Haskellian way. Any recommendations?

Answer 1

The smallest change you can make that works is to use dropWhile:

getNotes :: Note -> [Note]
getNotes root = take 12 . dropWhile (/= root) . cycle $ [minBound .. maxBound]