Simon Peyton-Jones said:

> But since the read may block, it matters *when* you perform it.
> For example if you print "Hello" and then read the IVar, you'll
> block after printing; but if you read the IVar and then print, the
> print won't come out. If the operation was pure (no IO) then you'd
> have a lot less control over when it happened.

But this is true of any expression in a non-strict language.

Why the special treatment of IVars?

Nikhil