Lazy IO?

[Duncan Coutts]

On Tue, 3 Sep 2002 14:49:45 -0400
Sengan.Baring-Gould@nsc.com wrote:

> Is there any way to make the IO Monad lazy?
> 
> The simplified version of my problem is that I want to
> generate an infinite structure from an IOArray and then
> consume only the relevant part of it.

Yes, unsafeInterleaveIO.

http://www.haskell.org/ghc/docs/latest/html/base/System.IO.Unsafe.html#unsafeInterleaveIO

This is how getContents is implemented so that it reads the file lazily.

Be careful of course it is "unsafe".

Duncan