Re^2: How to make references more like aliases?

Prior Nacre V,
I generally don't like passing whole arrays

Neither do I. But what you did is likely even more work than passing the whole array. Your code is equivalent to the following:

Make a reference to every element in the array
Make a copy for the anonymous array
Pass the reference to the anonymous array

To avoid making copies and only passing a reference, that should have been by_groups_of( 3, \@array ). Additionally, an iterator should stop when it is finished. In your code, you have to explicitly force it to abandon the infinite loop.

I do appreciate the reply and finding the fencepost bug. See this node for the latest version.

Cheers - L~R

Comment on Re^2: How to make references more like aliases?

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Re^3: How to make references more like aliases? by Prior Nacre V (Hermit) on Sep 29, 2004 at 05:57 UTC
Benchmarking disagrees with you. The closure is generated only once - my code does more here: `by_groups_of( 3, \@array ); by_groups_of( 3, [ \(@array) ] );` [download] The closure is called multiple times - your code does more here: `return sub { \@_ }->( @$list[ $start .. $stop ] ); return [ @{$ra_list}[$start .. $stop] ];` [download] I benchmarked on a P3/Win98 system using both Cygwin/Perl5.6 and Msys/Perl5.8. I got comparable results for both versions (no discernible speed differences). These results were repeated when volume testing with array sizes between 100,000 and 500,000. At the end of the day, either will do nicely :-) Regards, PN5	[reply] [d/l] [select]
Re^4: How to make references more like aliases? by Limbic~Region (Chancellor) on Sep 29, 2004 at 13:29 UTC
Prior Nacre V, Benchmarking disagrees with you. Then you misunderstood what I said. I made no claim my code was faster, only that your statement (I generally don't like passing whole arrays), seemed odd given what you were doing is more work than passing a whole array. Now my goal was being user-friendly, not being fast which is why I preferred `$group->[1] over ${ $group->[1] }`. But since you did bring up speed, my rudimentary tests show my code as being much faster. Perhaps you should try the following: Read more... (2 kB) Cheers - L~R	[reply] [d/l] [select]
Re^5: How to make references more like aliases? by Prior Nacre V (Hermit) on Sep 30, 2004 at 03:14 UTC
This was intended to be friendly, helpful and non-competitive. Perhaps you could've replied in a similar vein along these lines: Thanks for taking the extra time to compare benchmark results. However, further testing on the intended (platform/OS/Perl version) indicates that my version will run faster and therefore I will be going with that solution. Instead of: Using an unsubstantiated claim about what I understand. Are you psychic? Including pointless rhetoric. Neither you nor I claimed your (or my) code was faster. Perhaps take a moment to consider why you added this. Taking my statements out of context. Yet again you have focussed on passing array vs. arrayref while ignoring what is happening in the closure. Claiming I was talking about speed when I was, in fact, talking about speed differences (the former is absolute, the latter is relative). Finally, I very much doubt that anyone able to understand the closure generation code will have the slightest problem dereferencing a scalarref. As such, I believe your initial target for improving user-friendliness should be the closure. Regards, PN5	[reply]