Re: List::BinarySearch and conditional tests with Test::More

"Am I missing something here, or should I contact the module author? :-)"

Knowingly or not, you just did! :)

tobyink is on the right track, though you should be passing the haystack array by reference if you override the prototypes because the prototype is (&$\@), so pass by ref is what the function expects. ...I mention this in a followup to tobyink's otherwise perfect solution.

As for the funky import override: I used goto &subroutine instead of calling SUPER::subroutine() because the former fixes up the call stack nicely so that Exporter::import never knows something else came first. But in retrospect, it probably wouldn't hurt to just call SUPER::....

Oh, and the reason that we're overriding import in the first place is because in Perl versions prior to 5.20 there was a problem where a single use of $a and $b in your script (except if affiliated with sort) would trigger some unwanted "used only once" warnings. This little import trick assured that $a and $b weren't used only once. ...an ugly hack. Come to think of it, I should probably only be overriding if I detect the Perl version predates 5.20, rather than the logic currently in place.

So if you aren't importing anything, it is probably a good idea to put no warnings 'once'; inside of the callback subroutine. If this seems even more ugly, it is... and it is not unique to List::BinarySearch either. List::Util and List::MoreUtils were suffering from the same nuisance as well, until Perl 5.20 came along, allowing $a and $b to become exempt from this warning.

If you feel strongly enough that the override/goto code should be done differently please (and I mean this in all honesty), submit an issue at https://github.com/daoswald/List-BinarySearch/issues. Issues that include code, tests, and a strong argument are highly compelling to me. ;)

At any rate, if this discussion doesn't lead you to a workable solution, please do post a GitHub issue so that it remains enough of an annoyance to me that I fix it. I despise leaving issues unresolved. :)

Dave

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Re^2: List::BinarySearch and conditional tests with Test::More by glasswalk3r (Friar) on Nov 30, 2014 at 17:42 UTC
Fantastic davido... thank you for going through all the details. I'll check out if implementing those changes would avoid those errors and warnings without breaking anything and I'll let you know. Alceu Rodrigues de Freitas Junior --------------------------------- "You have enemies? Good. That means you've stood up for something, sometime in your life." - Sir Winston Churchill	[reply]
Re^3: List::BinarySearch and conditional tests with Test::More by davido (Cardinal) on Dec 01, 2014 at 16:58 UTC
For what it's worth, I put out a new version of List::BinarySearch today. The difference is subtle, and probably unimportant: In the previous version there was always a custom `import`, and that function did different things based on the Perl version number. In the new version there is only a custom import under versions of Perl that need it. The rest of the time we just accept what Exporter gives us. It still uses the `goto &...` idiom; calling through SUPER proved to be a little too fragile for our needs. Dave	[reply] [d/l] [select]