[Haskell-cafe] newbie questions (read, etc., with Data.ByteString.Lazy.Char8)

[wman]

the problem is that using readInt is actually _as slow_, at least using my
test script :-((

On Tue, Oct 7, 2008 at 5:12 AM, Don Stewart <dons at galois.com> wrote:

> 666wman:
> >    a slight modification to compile it :
> >
> >    change:
> >    where sumFile = sum . map read . L.words
> >    to :
> >    where sumFile = sum . map (read . L.unpack) . L.words
> >
> >    but it's actually _slower_ than the non-bytestring version.
>
> Never unpack a bytestring.
>
>    import qualified Data.ByteString.Lazy.Char8 as S
>
>    main = print . go 0 =<< S.getContents
>      where
>        go n s = case S.readInt s of
>                        Nothing     -> n
>                        Just (k,t)  -> go (n+k) (S.tail t)
>
> Assuming you're reading int, integers or doubles.
>
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