How do I read two items at a time in a Perl foreach loop?

Question

What I'm looking for is something like:

@list = qw(1 2 3 4 5 6);
foreach (@list) {
  #perl magic goes here 
  print "i: $i, j:$j
";
}

returns:

i:1, j:2
i:3, j:4
i:5, j:6

In response to a very good suggestion below, I need to specify that this script will run on someone else's build server, and I'm not allowed to use any modules from CPAN. Standard Perl only.

question from:https://stackoverflow.com/questions/569772/how-do-i-read-two-items-at-a-time-in-a-perl-foreach-loop

Answer 1

I believe the proper way to do this is to use natatime, from List::MoreUtils:

from the docs:

natatime BLOCK LIST

Creates an array iterator, for looping over an array in chunks of $n items at a time. (n at a time, get it?). An example is probably a better explanation than I could give in words.

Example:

 my @x = ('a' .. 'g');
 my $it = natatime 3, @x;
 while (my @vals = $it->())
 {
     print "@vals
";
 }

This prints

a b c
d e f
g

The implementation of List::MoreUtils::natatime:

sub natatime ($@)
{
    my $n = shift;
    my @list = @_;

    return sub
    {
        return splice @list, 0, $n;
    }
}