On 2008 Aug 27, at 17:09, Christopher Lane Hinson wrote:
WDYT about using RULES to rewrite to nubOrd if an Ord context is available, as John Meacham mentioned?
John: you said you were uneasy about changing the complexity of an algorithm using RULES, but this is exactly what list fusion does (albeit for space, not time).
Indeed. and I am a little uneasy about that too :) not that I don't think it is an excellent idea and reap the benefits of fast list operations.. O(n^2) to O(n log n) just feels like a bigger jump to me
Using RULES in this way could be a pessimization. I can't imagine a nubOrd that would ever be as performant as nub on very small data sets (two or three elements).
I think if you're in a situation where the performance of nub on such a small dataset matters, you're already well into the realm of controlling everything manually to get performance. -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH