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module Storage(
Store,
createStore,
setPref,
checkPref
) where
import qualified Control.Monad.Primitive as Prim
import qualified Data.Vector.Unboxed.Mutable as Vec
import qualified Data.Int as Ints
data Store = Store { pointer :: Vec.MVector Prim.RealWorld Ints.Int8
, sizeOfBallot :: Int}
createStore :: Int -> Int -> IO Store
createStore numberOfEntries ballotSize = do
v <- Vec.new (numberOfEntries * ballotSize)
return (Store v ballotSize)
setPref :: Store -> Int -> Int -> Int -> IO ()
setPref prefStore ballot position rank = do
let place = (ballot - 1) * (sizeOfBallot prefStore) + (position - 1)
Vec.write (pointer prefStore) place (fromIntegral rank)
checkPref :: Store -> Int -> Int -> Int -> IO Bool
checkPref prefStore ballot position rank = do
let place = (ballot - 1) * (sizeOfBallot prefStore) + (position - 1)
value <- Vec.read (pointer prefStore) place
return (value == (fromIntegral rank))
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