Hmm, this would make a good QuickCheck property. I wonder, is listify a contravariant functor? Fun to work through the details of that some time, I think.
Chad On 8/10/07, Brent Yorgey <[EMAIL PROTECTED]> wrote: > > Amusingly, extract is intimately related to function composition. Suppose we > have > > listify :: (Int -> Int) -> [Int] > listify = flip map [0..] > > Then if f, g :: Int -> Int, and f is monotonically increasing, we have the > identity > > (listify f) `extract` (listify g) = listify (g . f) > > This randomly occurred to me as I was falling asleep last night and I > thought I would share. =) > > -Brent _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
