Re^2: AI::Genetic gives me strange warnings

Right - the second time you try that sort, $a and $b are undef each time the block is evaluated. Furthermore, it appears that sort-within-sort only breaks if the inner sort is in a different package than the outer sort, as you'll notice that when I do the sort myself (inside main) there's no problem.

Also, see my other reply that exhibits this phenomenon without using AI::Genetic.

--
@/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/;
map{y/X_/\n /;print}map{pop@$_}@/for@/
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Re^3: AI::Genetic gives me strange warnings by Tanktalus (Canon) on Feb 23, 2005 at 15:10 UTC
As ugly as it seems, a workaround (not denying a likely perl bug here) is to use $::a and $::b in the inner sort. Which may mean patching AI::Genetic... although I don't know what that will do during non-embedded sorts.	[reply]
Re^4: AI::Genetic gives me strange warnings by fizbin (Chaplain) on Feb 23, 2005 at 15:23 UTC
Actually, there's a much, much easier patch to AI::Genetic that doesn't potentially screw up other non-embedded sorts. I've already communicated this to the AI::Genetic author, but you can see what's necessary in (the updated) 433606. It relies on the fact that individuals in an AI::Genetic population remember their score values once they've computed them. (Which is necessary for even vaguely decent performance when the fitness function gets a bit hairy) It's a very small three-line change, and does leave open the possibility of people screwing with the internals of the AI::Genetic object if they assign to $_, but you shouldn't be assigning to $_ in any case without using `local` to limit the effects of your changes. Also note that it's not the inner sort you'd be changing if you're changing AI::Genetic but the outer sort; the inner sort is already inside package main. `-- @/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/; map{y/X_/\n /;print}map{pop@$_}@/for@/` [download]	[reply] [d/l] [select]