What is the best way in Perl to iterate a loop and extract pairs or triples

Question

I have a flat array of coordinates and I want to iterate and extract pairs of x and y coordinates. The same logic could apply to triples for RGB colors. This is what I have so far, but it doesn't feel super flexible or elegant.

my @coords = qw(1 5 2 6 3 8 6 12 7 5);

for (my $i = 0; $i < @coords; $i += 2) {
    my $x = $coords[$i];
    my $y = $coords[$i+1];

    print "$x, $y\n";
}

There has to be a better way to do this right?

Answer 1

The module List::MoreUtils has natatime (n-at-a-time)

use List::MoreUtils qw(natatime);

my @ary = 1..12; 

my $it = natatime 3, @ary;  # iterator

while (my @triplet = $it->()) { say "@triplet" }

Answer 2

splice is a better way

while (my ($x,$y) = splice @coords, 0, 2) {
    ...
}

Two things to note.

1. splice consumes the elements of @coords. If you don't want your loop to destroy the contents of your array, use a temporary array.

      my @tmp = @coords;
      while (my ($x,$y) = splice @tmp,0,2) { ... }
   

2. If the input might not contain an even number of elements, you may want to add an additional check to make sure each iteration has access to the right number of elements

      while (2 == (my ($x,$y) = splice @coords,0,2)) { ... }