There's no such thing as "cheating", though that particular code won't
work for my purposes because it assumes the output is merely a stream
of "null". Fine for the benchmark, but not extractable to the full
problem.
I wonder: is Handle known to be particularly slow? This code only has
to work on Linux and BSD, so if using (for example) a POSIX fd would
be much faster, it could bring the Haskell version much closer to C.
On Fri, Jan 22, 2010 at 07:30, Tom Nielsen
It seems to me this indicates that the big expense here is the call into the I/O system.
So let's make fewer I/O calls:
import Control.Monad import qualified Data.ByteString.Char8 as S import System.IO
null_str1 = S.concat $ take 1000 $ repeat $ S.pack "null"
n1 = 5000000 `div` 1000
main = withBinaryFile "out3.json" WriteMode $ \h -> do hPutStr h "[" replicateM_ n1 (S.hPutStr h null_str1) hPutStr h "]" --- this is 10x faster. Whether this is cheating or not depends on what John actually wants to do.
Tom