use Algorithm::Loops qw( NestedLoops );

my @spec = (
    [ 'static1'           ],
    [ 'ar1', 'ar2'        ],
    [ 'static2'           ],
    [ 'ar3', 'ar4', 'ar5' ],
);

NestedLoops(\@spec, sub {
    print(join(', ', @_), "\n");
});