sub multi_foreach(&@) { my $code = shift; if (@_ == 1) { for my $i (@{ shift() }) { $code->( $i ); } } elsif (@_ == 2) { my ($a0, $a1) = @_; for my $i0 (@$a0) { for my $i1 (@$a1) { $code->( $i0, $i1 ); } } } elsif (@_ > 2) { my ($a0, $a1, $a2, @rest) = @_; for my $i0 (@$a0) { for my $i1 (@$a1) { for my $i2 (@$a2) { if (@rest) { &multi_foreach_recursive( $code, scalar @rest, @rest, $i0, $i1, $i2 ); } else { $code->( $i0, $i1, $i2 ); } } } } } } multi_foreach { say join ' ', @_ } \( @a, @b, @c );