Re: Re: Adventures in optimization (or: the good and bad side of being truly bored)

[diotalevi]

And to add caching - Memoize!

As for actual profiling, its really easy to run your scripts under Devel::DProf (which comes with perl don'cha know) `perl5 -d:DProf test.pl` and after its finished, dprofpp. Sooper easy. I worked out an order of magnitude increase in some perl code speed by repeatedly testing my changes and assumptions against profiled code. And for those that are curious - it turns out that regex capturing can be a real dog some times.

[Limbic~Region]

diotalevi,
Your attention to detail never ceases to amaze me. I didn't want to mention Memoize at the beginning since it would not work for what revdiablo was trying to do, but I did want to mention it later as a "generally you can add caching simply by using Memoize by Dominus" and completely forgot.

Thanks - L~R

[revdiablo]

Indeed. Devel::DProf is good stuff. I was very happy with my results when using it and Benchmark to, erm, profile and benchmark my code.

As for Memoize, Limbic~Region's reply is correct. It won't really work for me in this case, because I willshould never have the case where my subroutine gets called twice with the same arguments (unless of course there's something wrong in my log and I get duplicate entries). Thanks for mentioning this though, I've been meaning to look at it for a good while now.

[diotalevi]

I just mentioned Memoize for the general case and the rest of our audience.

[demerphq]

Regarding Memoize, maybe im weird but i've never found it to be particularly useful. I have never had a real (dev and toy, ok) circumstance where I can cache based on arguments alone, and splitting my function into subfuctions that can be so Memoized never seemed to me to be the right thing to do. I think caching properly requires some degree of thought and understanding of the overall process, which combined with the ease of establishing a cache in Perl I have never used Memoize in any production code.


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demerphq

_{<Elian> And I do take a kind of perverse pleasure in having an OO assembly language...}