An "efficient" prime generator with the Sieve of Eratosthenes in Haskell, as close to point-free (= unreadable) as I could make it.

obfuscatedprimes.hs

import Control.Applicative (liftA2, liftA3)
import qualified Data.Map as M (empty, lookup, insertWith, delete)
import Data.Function (fix)
import Control.Monad (join)
primes = fix (flip (flip liftA2 head) tail . (liftA2 (liftA3 liftA2 (flip flip
    . M.lookup)) (liftA2 ($) ((.) . (.) (liftA3 maybe) . (.) . (:)) . ((. flip
    (.) . liftA2 (M.insertWith (++)) (join (*)) (replicate 1)) . flip (.)))
    (((. flip (.) . liftA2 (.) (foldl . ((. flip flip) . flip flip (replicate
    1) . flip liftA2 . (.) (M.insertWith (++)) . (+))) M.delete) . (flip (.))
    . (.) (.) ) ))) [2..] M.empty