Re: [Haskell-cafe] Lazy IO.

14 Jun 2008

      (Sorry, Sebastiaan, I hit send accidentally)

On Sat, Jun 14, 2008 at 1:18 PM, Sebastiaan Visser  wrote:
...
readHttpMessage :: IO (Headers, Data.ByteString.Lazy.ByteString)
 readHttpMessage = do
   myStream <- <accept http connection from client>
   request <- hGetContents myStream
   header <- parseHttpHeader request
   bs <- Data.ByteString.Lazy.hGetContents myStream
   return (header, body)
Why not

readHttpMessage = do
  myStream <- <accept http connection from client>
  data <- Data.ByteString.Lazy.hGetContents myStream
  (header, rest) <- parseHttpHeader data
  return (header, rest)

i.e. make parseHttpHeader return the rest of the string it didn't parse?

In fact, may I ask why parseHttpHeader is not a pure function?

HTH,

-- Felipe.

Re: [Haskell-cafe] Lazy IO.

Felipe Lessa