A function for testing insert/lookup times of cuckoo hash table with pathological data.

CuckooChameleon.hs

import Data.Hashable
import Control.Monad.ST
import qualified Data.HashTable.ST.Cuckoo as HT
    
data HashCollider = HashCollider String Int
                  deriving (Eq, Show)

instance Hashable HashCollider where
    hashWithSalt salt (HashCollider name value) = salt + value

test :: Int -> Int -> [Maybe String]
test insertCount lookupCount = runST $ do
         table <- HT.new
         let keys = take insertCount (generateKeys 1)
             values = take insertCount (generateValues 1)
         mapM (uncurry $ HT.insert table) (zip keys values)
         sequence (map (HT.lookup table) (take lookupCount $ cycle keys))
                    
generateKeys :: Int -> [HashCollider]
generateKeys n = (HashCollider ("key" ++ show n) 1234) : generateKeys (n+1)

generateValues :: Int -> [String]
generateValues n = ("value" ++ show n) : generateValues (n+1)