net-ldap-0.1.1 gives invalid filter syntax cuz of parenthesi

Things like this won't work.. they fail with Invalid filter syntax
filter = Net::LDAP::Filter.construct("nisnetgrouptriple=(,user,)")
If I remove the parenthesis and it works fine.

or if you use
filter = Net::LDAP::Filter.eq( "nisnetgrouptriple", "(,user,)" )
then that works fine..

but i want to have compound statements and take them from a web front
end so this is all tedious to construct.

This will fail with invalid filter syntax as well:
filter =

Anyone found better work arounds for things like this other than going
to ruby/ldap c based gem?