import qualified Network.Riak.Basic as R (connect, delete, foldKeys)
import qualified Network.Riak.Types as R
import qualified Network.Riak.Content as R (Content(..), Link, link)
import qualified Network.Riak.Value.Monoid as R

getMulti :: (Monoid c, R.IsContent c) => R.Connection -> R.Bucket -> [R.Key] -> IO [Maybe (c, R.VClock)]
getMulti c b k = R.getMany c b k R.Default

putMulti :: (Eq c, Monoid c, R.IsContent c) => R.Connection -> R.Bucket -> [R.Key] -> [c] -> IO [(c, R.VClock)]
putMulti c b k v = do vc <- map (snd `fmap`) `liftM` getMulti c b k
                      R.putMany c b (zip3 k vc v) R.Default R.Default


fails with:


slurp.hs:119:54:
    Ambiguous type variable `c' in the constraints:
      (Monoid c) arising from a use of `getMulti' at slurp.hs:119:54-61
      (R.IsContent c) arising from a use of `getMulti'
                      at slurp.hs:119:54-61
    Probable fix: add a type signature that fixes these type variable(s)
    In the second argument of `liftM', namely `getMulti c b k'
    In a stmt of a 'do' expression:
        vc <- map (snd `fmap`) `liftM` getMulti c b k
    In the expression:
      do { vc <- map (snd `fmap`) `liftM` getMulti c b k;
           R.putMany c b (zip3 k vc v) R.Default R.Default }