Re: [Haskell-cafe] strict, lazy, non-strict, eager

(I’m somewhat dismayed that the error in my preliminary remark has overshadowed the point of my original message — which was about the distinction between lazy and non-strict. However…) David Barbour writes:

Full beta-reduction is certainly not strict

What, precisely, do you mean by “full beta-reduction”?

but also doesn't guarantee terminate even where it is possible (i.e. it might indefinitely unfold a value without making progress).

That sounds very much to me like being overly strict.

I don't think there is much you can say about non-strictness and termination.

I would hope there would be, as that (or at least productivity) is the point of saying that Haskell has non-strict semantics.

On Mon, Jan 9, 2012 at 3:01 AM, Jon Fairbairn wrote:

...

Perhaps what I should have said to be almost as succinct but this time accurate is “non-strict semantics requires that the evaluation strategy terminate if there is any evaluation strategy that terminates”?

-- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk