On Mon, 2005-11-28 at 07:27 -0500, Dimitry Golubovsky wrote:
This may be a stupud question, but how to make I/O in Haskell really lazy?
What is desired is to have the IO actions perform as their results are needed. I am assuming some knowledge that those actions have only limited scope of side effects (e. g. order of outputs within a window is significant, but order of appearance of those windows on the screen may not be). I see some way to do this by writing regular non-monadic Haskell stuff, representing each side effects scope (i. e. where ordering of actions is necessary) with its own instance of an I/O like monad (but runnable from an outside non-monadic code), and then using unsafePerformIO as needed. But there may be some framework already developed (albeit with unsafePerformIO, but hiding it from application developers).
Any ideas, pointers?
unsafeInterleaveIO http://haskell.org/ghc/docs/latest/html/libraries/base/System-IO-Unsafe.html... Duncan