sub signatures coming

[Yitzchak Scott-Thoennes]

The blog post modified the original from returning an arrayref to
returning a list.

Restoring the arrayref, I'd:

use Algorithm::Loops 'MapCarE';
use List::Util 'sum';
sub pairwise_sum { [ MapCarE { sum @_ } @_ ] }

(note that the only improvement offered by 5.19.9 would be to
arbitrarily limit it to two arrays)

On Tue, Feb 25, 2014 at 8:17 AM, Paul Makepeace <paulm at paulm.com> wrote:
> On Feb 25, 2014 7:16 AM, "James Laver" <james.laver at gmail.com> wrote:
>>
>>
>> On 25 Feb 2014, at 11:31, Matt Lawrence <matt.lawrence at virgin.net> wrote:
>>
>> > On 25/02/14 11:18, James Laver wrote:
>> >>
>> >> But I probably already have List::MoreUtils imported (because Perl).
>> >>
>> >> sub pairwise_sum ($a1, $a2) {
>> >>   zip @$a1, @$a2;
>> >> }
>> >>
>> >> And lets ignore the fact that the perl version that was used in the
> article was buggy. If $arg2 is shorter than $arg1 it breaks. zip's supposed
> defined behaviour is to stop when either list runs out of elements.
>> >
>> > Whereas this one is buggy because it doesn't actually do what it says
> on the tin. Where's the summation?
>> >
>> > Matt
>>
>> Ah yes. I'd just woken up.
>>
>> sub pairwise_sum($a2,$a2) {
>>   map {shift($_)+shift($_)} (zip @$a1, @$a2);
>> }
>
> You aren't making a good case for perl here :)
>
>>
>> James