On 16 July 2013 10:31, Ivan Lazar Miljenovic <ivan.miljeno...@gmail.com> wrote: > 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 :/
This discussion (on -cafe@) is just about what course of action to take; adding such functions to containers or unordered-containers would not require a libraries@ proposal. Conrad. > >> >> >> >> 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 > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
