Negative regex matches

[mojodna]

Carto already has =~, !~ is its complement.

[springmeyer]

Interested in providing a patch for this? If so trying to get more to the bottom of #213 would be good - I tend to not recommend people use regex due to #213.

[yvecai]

Not so sure it would be just an enhancement, in XML this can be done and can be very useful:
<Filter>![key].match('.*value.*')</Filter>