29 Apr
2010
29 Apr
'10
2:43 p.m.
Ah, thanks!
b
On Thu, Apr 29, 2010 at 11:37 AM, Daniel Fischer
Am Donnerstag 29 April 2010 20:08:00 schrieb Ben:
A technical question: it seems like the instance of ArrowLoop is too strict (this is something I've wondered about in Liu's paper too.) Shouldn't it be
instance ArrowLoop SFAuto where loop (SFAuto s f) = SFAuto s f' where f' (b, s1) = let (~(c, d), s2) = f ((b, d), s1) in (c, s2)
Let-bindings are already lazy, so the '~' makes no difference here. Apart from the readability, both are the same as
where f' (b,s1) = let x = f ((b, snd $ fst x),s1) in (fst $ fst x, snd x)