HashTable-Lückencode

HashTable.hs

#!/usr/bin/env stack
-- stack --resolver lts-6.4 --install-ghc runghc --package primitive --package hashable --package vector

module HashTable where

import Prelude hiding (lookup)
import Control.Monad.Primitive (PrimMonad (..))
import Data.Hashable (Hashable (..))
import qualified Data.List as L
import qualified Data.Vector.Mutable as VM

data MutHashTable s k v
  = MutHashTable ()

htSize :: Int
htSize = 2 ^ 12

empty :: PrimMonad m => m (MutHashTable (PrimState m) k v)
empty = _

lookup
  :: (Hashable k, Eq k, PrimMonad m)
  => k
  -> MutHashTable (PrimState m) k v
  -> m (Maybe v)
lookup key (MutHashTable vec) =
  _

insert
  :: (Hashable k, Eq k, PrimMonad m)
  => k
  -> v
  -> MutHashTable (PrimState m) k v
  -> m ()
insert key value (MutHashTable vec) =
  _

delete
  :: (Hashable k, Eq k, PrimMonad m)
  => k
  -> MutHashTable (PrimState m) k v
  -> m ()
delete key (MutHashTable vec) =
  _

main :: IO ()
main = do
  ht <- empty
  lookup "bar" ht >>= assertEqual Nothing
  insert "bar" 42 ht
  lookup "bar" ht >>= assertEqual (Just 42)
  lookup "foo" ht >>= assertEqual Nothing
  delete "bar" ht
  lookup "bar" ht >>= assertEqual Nothing
  where
    assertEqual expected actual =
      if expected == actual then
        return ()
      else
        fail $ "expected " ++ show actual ++ " to be " ++ show expected