[Haskell-cafe] efficient chop
Kazu Yamamoto ( 山本和彦 )
kazu at iij.ad.jp
Wed Sep 14 09:17:16 CEST 2011
You can find the results of my friend:
Please ignore the Japanese text. Please read the code and the results.
I'm not sure why you had the different result.
> This was exactly my first attempt on rewriting your foldr version.
> Unfortunately, it doesn't seem faster at all (foldr2 below).
> The test input was replicate 100 'a' ++ replicate 100 ' '.
> GHC 7, -O2.
> benchmarking all/foldr
> mean: 2.808462 us, lb 2.807047 us, ub 2.810520 us, ci 0.950
> std dev: 8.620822 ns, lb 6.535738 ns, ub 11.59552 ns, ci 0.950
> benchmarking all/reverse
> mean: 4.128217 us, lb 4.125409 us, ub 4.134086 us, ci 0.950
> std dev: 20.07591 ns, lb 11.47572 ns, ub 38.33738 ns, ci 0.950
> benchmarking all/foldr2
> mean: 6.701714 us, lb 6.692093 us, ub 6.711627 us, ci 0.950
> std dev: 50.06638 ns, lb 42.25004 ns, ub 64.84223 ns, ci 0.950
> Roman I. Cheplyaka :: http://ro-che.info/
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