module Main where
import qualified Data.ByteString.Lazy as B
import Data.ByteString.Nums.Careless -- from bytestring-nums package
bint :: B.ByteString -> Int
bint = int
main = do
line : rest <- B.split 10 `fmap` B.getContents
let [n, k] = map int . B.split 32 $ line
putStrLn . show . length . tail . filter ((==0).(`mod`k).bint) $ rest
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---------- Forwarded message ----------
From: Eugene Kirpichov <ekirpichov@gmail.com>
Date: 2009/08/30
Subject: Re: [Haskell-cafe] Slow IO?
To: Steve <stevech1097@yahoo.com.au>
Cc: haskell-cafe@haskell.org
module Main where
import qualified Data.ByteString.Lazy as B
import Data.ByteString.Nums.Careless -- from bytestring-nums package
bint :: B.ByteString -> Int
bint = int
main = do
line : rest <- B.split 10 `fmap` B.getContents
let [n, k] = map int . B.split 32 $ line
putStrLn . show . length . tail . filter ((==0).(`mod`k).bint) $ rest
This does a 100MB file in 2.7s (probably because the file is cached by
the filesystem).
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