Re: [TxMt] feature request: on-the-fly-bundles?

On Aug 21, 2005, at 11:06 PM, Allan Odgaard wrote:

allow dynamic scopes (like snippet placeholders, current word etc.) and to keep the patterns, which are created for context sensitive behavior, outside the language grammars -- with beta 17's (unreleased as of this writing) ability to perform set operations on scope selectors, this does make a lot of sense. E.g. specify foldings as: "other.folding-keyword - (string | comment)" or let the invalid coloring exclude current word by using: "invalid.illegal - dyn.current-word"

What all made it into b17? Where do I find info about "beta 17's ... ability to perform set operations on scope selectors"?