On 16 July 2013 11:46, John Lato <jwl...@gmail.com> wrote: > In my tests, using unordered-containers was slightly slower than using Ord, > although as the number of repeated elements grows unordered-containers > appears to have an advantage. I'm sure the relative costs of comparison vs > hashing would affect this also. But both are dramatically better than the > current nub. > > Has anyone looked at Bart's patches to see how difficult it would be to > apply them (or re-write them)?
If I understand correctly, this function is proposed to be added to Data.List which lives in base... but the proposals here are about using either Sets from containers or HashSet from unordered-containers; I thought base wasn't supposed to depend on any other package :/ > > > > On Mon, Jul 15, 2013 at 8:43 PM, Clark Gaebel <cgae...@uwaterloo.ca> wrote: >> >> Apologies. I was being lazy. Here's a stable version: >> >> import qualified Data.HashSet as S >> >> hashNub :: (Ord a) => [a] -> [a] >> hashNub l = go S.empty l >> where >> go _ [] = [] >> go s (x:xs) = if x `S.member` s then go s xs >> else x : go (S.insert x s) xs >> >> Which, again, will probably be faster than the one using Ord, and I >> can't think of any cases where I'd want the one using Ord instead. I >> may just not be creative enough, though. >> >> >> - Clark >> >> On Mon, Jul 15, 2013 at 12:46 AM, Brandon Allbery <allber...@gmail.com> >> wrote: >> > On Sun, Jul 14, 2013 at 7:54 AM, Clark Gaebel <cgae...@uwaterloo.ca> >> > wrote: >> >> >> >> Oops sorry I guess my point wasn't clear. >> >> >> >> Why ord based when hashable is faster? Then there's no reason this has >> >> to >> >> be in base, it can just be a >> > >> > Did the point about "stable" fly overhead? >> > >> > -- >> > brandon s allbery kf8nh sine nomine >> > associates >> > allber...@gmail.com >> > ballb...@sinenomine.net >> > unix, openafs, kerberos, infrastructure, xmonad >> > http://sinenomine.net >> >> _______________________________________________ >> Haskell-Cafe mailing list >> Haskell-Cafe@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-cafe > > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com http://IvanMiljenovic.wordpress.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
