a very quick question about ByteString lib
daniel.is.fischer at web.de
Tue Oct 27 12:00:37 EDT 2009
Am Dienstag 27 Oktober 2009 16:47:12 schrieb Thomas DuBuisson:
> If you wanted to make sure it didn't have to do with ghci then you
> should have compiled the original code, not tested different
> functions. The code you provided works fine compiled and I too am
> curious what is going on when you run it in ghci.
Look at the sources:
hGetLine :: Handle -> IO ByteString
hGetLine h = System.IO.hGetLine h >>= return . pack . P.map c2w
hGetLine h = wantReadableHandle "Data.ByteString.hGetLine" h $ \ handle_ -> do
case haBufferMode handle_ of
NoBuffering -> error "no buffering"
_other -> hGetLineBuffered handle_
So, in ghci, stdin isn't buffered and ByteString can't cope with that. Why exactly, I
Change code to
main = hSetBuffering stdin LineBuffering >> B.getLine >>= B.putStrLn
and it works.
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