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\n'; } 

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.

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\n';  } 

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;     } }