harrop_ghc.hs

-- stack --resolver nightly-2017-02-08 ghc --package hashtables -- -O2 harrop_ghc.hs
import           Control.Monad
import qualified Data.HashTable.IO as H

type HashTable k v = H.BasicHashTable k v

main = do
  m <- H.new :: IO (HashTable Int Int)
  forM_ [1..10000000] $ \n -> H.insert m n n
  v <- H.lookup m 100
  print v

harrop_ocaml.ml

(* ocamlopt -o harrop_ocaml harrop_ocaml.ml *)
let n = 10000000

let () =
  let m = Hashtbl.create n in
  for n=1 to n do
    Hashtbl.add m n n
  done;
  Printf.printf "%d\n%!" (Hashtbl.find m 100)