DB<34> sub cross (&$$) { my ($code,$list1,$list2) = @_; local ($a,$b); my @res; for $a (@$list1) { for $b (@$list2) { push @res, &$code }}; return @res; }

  DB<35> x cross { $a + $b } [0..2], [10,20,30]
0  10
1  20
2  30
3  11
4  21
5  31
6  12
7  22
8  32
  DB<36>