Benchmark template for TiPL 2012, for testing map implementations

mapbench.hs

-- Benchmark template for TiPL 2012, for testing map implementations  
-- Compile with the command: ghc -O3 -W --make mapbench.hs -o mapbench

import qualified Criterion.Main as C

isPrime :: Integral a => a -> Bool
isPrime n = null [factor | factor <- [2..floor $ sqrt $ fromIntegral n]
                         , n `mod` factor == 0]

numbers = [2,3..]

kmap f = foldr (\x res -> f x : res) [] 

main = do
  let sizes = [ 10000, 100000, 1000000]
      inputs = [(n, take n numbers) | n <- sizes]
      benchmarks = [ C.bench (name ++ show n) $ C.nf mapprime ns
                   | (n, ns)         <- inputs,
                     (name, mapprime) <- [("Data.List.map ",  map$isPrime),
                                          ("kmap "         , kmap$isPrime)]]
  C.defaultMain benchmarks