[Haskell-cafe] Re: Silly I/O question

[Peter Simons]

John Goerzen writes:

 > But the block I/O in Haskell makes no sense to me (how do
 > I allocate a Ptr type block thingy)?

With mallocArray. Block I/O is difficult, though.


 >> You might want to write a function that copies the file
 >> _once_ and then just call that function several times.

 > If I load it into memory, yes. Otherwise, it seems not so
 > easy.

Looking at your program:

 > main = disp 100

 > disp 0 = return ()
 > disp n =
 >     let copy x = do
 >                eof <- isEOF
 >                if eof
 >                   then return ()
 >                   else do
 >                        line <- getLine
 >                        putStrLn line
 >                        (copy 0)
 >         in do
 >            copy 0
 >            hSeek stdin AbsoluteSeek 0
 >            disp (n-1)

Just let the function _begin_ with the seek, copy the file,
and return. Then call it 100 times. No recursion.

Peter