Set::CrossProduct 1.92

Set::CrossProduct is a Perl module that allows you to work with the cross product of two or more sets.

SYNOPSIS

my $iterator = Set::CrossProduct->new( ARRAY_OF_ARRAYS );

# get the next tuple
my $number_of_tuples = $iterator->cardinality;

# get the next tuple
my $tuple = $iterator->get;

# move back one position
my $tuple = $iterator->unget;

# get the previous tuple without resetting
# the cursor (peek at it)
my $next_tuple = $iterator->next;

# get the previous tuple without resetting
# the cursor
my $last_tuple = $iterator->previous;

# get a random tuple
my $tuple = $iterator->random;

# in list context returns a list of all tuples
my @tuples = $iterator->combinations;

# in scalar context returns an array reference to all tuples
my $tuples = $iterator->combinations;

Given sets S(1), S(2), ..., S(k), each of cardinality n(1), n(2), ..., n(k) respectively, the cross product of the sets is the set CP of ordered tuples such that { | s1 => S(1), s2 => S(2), .... sk => S(k). }
If you do not like that description, how about:

Create a list by taking one item from each array, and do that for all possible ways that can be done, so that the first item in the list is always from the first array, the second item from the second array, and so on.