Re^3: Pointers and References

I don't really think of mutable arguments like that as "output parameters". "I/O parameters" maybe. I the sense that C like languages use output parameters where the sole job of the parameter is to return information from the function I don't see a need for output parameters in Perl, although passing references in the parameter list could be used that way.

The run time and memory cost of returning a reference to a large structure, or a list of references to large structures has essentially the same overhead on Perl as passing references back as parameters. Since returning a list of stuff is natural in Perl returning a list of references makes for easier to understand code than working with output parameters.

Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond

Comment on Re^3: Pointers and References

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Re^4: Pointers and References by bliako (Monsignor) on Nov 24, 2020 at 01:21 UTC
I have to say I come from C and back then (yes! Then) without goofle and the free literature it was a lot of hard work to conquer the pointers. I can't let it go now. I have often debated internally whether thinking in C while writing Perl was a good habit/idea/practice. It is NOT. But when %$^$& comes to shovel I have to think of some ways to make it faster. Because I am too lazy to program it in C eventually. And these are some of the tricks I pull. That's why my subs most of the times have a hashref of params as input (as opposed to array-style `(file => 'aaa' , action => 'delete')`) and I always return a hashref or arrayref or object back, but never ever an array. I think somewhere an angel dies when I do that. Cargo-culting perhaps, plus I am not a natural Perl-er. bw, bliako	[reply] [d/l]
Re^5: Pointers and References by LanX (Saint) on Nov 24, 2020 at 12:17 UTC
> ... as opposed to array-style ... but never ever an array ... Probably nitpicking: You say "array" but mean "list". :) Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply]
Re^6: Pointers and References by bliako (Monsignor) on Nov 24, 2020 at 19:33 UTC
Thanks for pointing this out LanX Perhaps that's the reason I return a (array)ref: I don't want to say list! Because when I think I grasped the distinction list vs array, something proves me wrong again. But hey when in Perl speak Perl (even if some/quite-a-few publications use the terms interchangebly). I would prefer anonymous, readonly (fixed-size) array of readonly (lest they be references) items. But here is a quick question: you can't modify a list item in say a foreach loop `foreach my $x (1,2,3){ $x = 42 }` (Modification of a read-only value attempted) but in the parameter list to a sub you can: `$_[0] = 12` (as jcb demonstrated earlier). bw, bliako	[reply] [d/l] [select]
Re^7: Pointers and References by LanX (Saint) on Nov 24, 2020 at 19:52 UTC
Re^8: Pointers and References by bliako (Monsignor) on Nov 24, 2020 at 20:38 UTC
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Re^8: Pointers and References by Leudwinus (Scribe) on Nov 25, 2020 at 15:33 UTC
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Re^7: Pointers and References by AnomalousMonk (Archbishop) on Nov 24, 2020 at 20:13 UTC
Re^8: Pointers and References by Leudwinus (Scribe) on Nov 25, 2020 at 15:37 UTC
Re^8: Pointers and References by bliako (Monsignor) on Nov 24, 2020 at 20:44 UTC


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