Global variables?

Andrew J Bromage
Mon, 3 Feb 2003 10:49:06 +1100

G'day all.

On Fri, Jan 31, 2003 at 09:08:22AM +0100, Ralf Hinze wrote:

> John Hughes wrote a nice pearl on the subject, see

Nice!  Why isn't RefMonad in hslibs?

Possibly because of the class signature:

	class Monad m => RefMonad m r | m -> r where
		{- etc -}

It makes perfect sense for there to be more than one kind of "ref"
for a given monad.  Indeed, sometimes it's important.  Quite often, I
use a custom ref built on top of IORef which supports Ord, as this is
needed for hash consing.

Andrew Bromage