Neil Mitchell wrote:
I'm trying to write out a binary file, in particular I want the following functions:
hPutInt :: Handle -> Int -> IO ()
hGetInt :: Handle -> IO Int
For the purposes of these functions, Int = 32 bits, and its got to roundtrip - Put then Get must be the same.
How would I do this? I see Ptr, Storable and other things, but nothing which seems directly useable for me.
hPutInt h = hPutStr h . map chr . map (0xff .&.) . take 4 . iterate (`shiftR` 8) hGetInt h = replicateM 4 (hGetChar h) >>= return . foldr (\i d -> i `shiftL` 8 .|. ord d) 0 This of course assumes that a Char is read/written as a single low-order byte without any conversion. But you'd have to assume a lot more if you started messing with pointers. (Strange, somehow I get the feeling, the above is way too easy to be the answer you wanted.) Udo. -- Worrying is like rocking in a rocking chair -- It gives you something to do, but it doesn't get you anywhere.