criterion-0.1.3: examples/Fibber.hs

{-# LANGUAGE ScopedTypeVariables #-}

import Criterion.Main

fib :: Int -> Int
fib n | n < 0     = error "negative!"
      | otherwise = go (fromIntegral n)
  where
    go 0 = 0
    go 1 = 1
    go n = go (n-1) + go (n-2)

fact :: Int -> Integer
fact n | n < 0     = error "negative!"
       | otherwise = go (fromIntegral n)
    where go 0 = 1
          go i = i * go (i-1)

fio :: Int -> IO Integer
fio n | n < 0     = error "negative!"
      | otherwise = go (fromIntegral n)
    where go i | i == 0    = return 1
               | otherwise = do
            j <- go (i-1)
            return $! i * j

main = defaultMain [
        bgroup "tiny" [ bench "fib 10" $ \n -> fib (10+n-n)
                      , bench "fib 15" $ \n -> fib (15+n-n)
                      , bench "fib 20" $ \n -> fib (20+n-n)
                      , bench "fib 25" $ \n -> fib (25+n-n)
                      ],
        bgroup "fib" [ bench "fib 10" $ \n -> fib (10+n-n)
                     , bench "fib 35" $ \n -> fib (35+n-n)
                     , bench "fib 37" $ \n -> fib (37+n-n)
                     ],
        bgroup "fact" [ bench "fact 100"  $ \n -> fact (100+n-n)
                      , bench "fact 1000" $ \n -> fact (1000+n-n)
                      , bench "fact 3000" $ \n -> fact (3000+n-n)
                      ],
        bgroup "fio" [ bench "fio 100"  (fio 100)
                     , bench "fio 1000" (fio 1000)
                     , bench "fio 3000" (fio 3000)
                     ]
       ]