forward Id a = a forward (ICons f _ r) a = forward r (f a) backward Id a = a backward (ICons _ f r) a = f (backward r a)
2009/12/29 Eugene Kirpichov <[email protected]>: > data IList a b where > Id :: IList a a > ICons :: (a -> b) -> (b -> a) -> IList b c -> IList a c > > 2009/12/29 Jonathan Fischoff <[email protected]>: >> This seems like exactly what I want, but there are two problems: I can't >> access the paper and it requires Generic Haskell. I'm just too much of newb >> to jump into generic Haskell :). >> >> On Mon, Dec 28, 2009 at 7:41 PM, Dan Weston <[email protected]> >> wrote: >>> >>> This might be pertinent: >>> >>> Alimarine et al, "There and Back Again: Arrows for Invertible Programming" >>> http://www.cs.ru.nl/A.vanWeelden/bi-arrows/ >>> >>> Jonathan Fischoff wrote: >>>> >>>> Hi, >>>> I would to create a list of tuples (or something similar) of invertible >>>> functions >>>> >>>> [((a -> b), (b -> a)), ((b -> c), (c -> b)), .... >>>> >>>> Such that I could call >>>> >>>> forward invertibleFuctionList domainValue = ? -- composite all the >>>> functions >>>> backward invertibleFuctionList rangeValue = forward (reverse >>>> invertibleFuctionList) rangeValue -- or something similar >>>> >>>> >>>> I would also like to concat them. This sounds like a job for GADT that >>>> someone might have already tackled. Any ideas? >>>> >>>> -Jonathan >>>> >>> >> >> >> _______________________________________________ >> Haskell-Cafe mailing list >> [email protected] >> http://www.haskell.org/mailman/listinfo/haskell-cafe >> >> > > > > -- > Eugene Kirpichov > Web IR developer, market.yandex.ru > -- Eugene Kirpichov Web IR developer, market.yandex.ru _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
