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) _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
