At some point I tried to use a similar idea to build an incremental parser generator for Emacs (2). Currently abandonware, but think it has potential!
Lots of regular expressions were used before and without control of the documents (which change over time) this kind of code was just unmanageably difficult to maintain.
Being able to use negative look ahead with lists of grammar symbols provides an incredibly large amount of power to resolve ambiguities and makes it relatively easy to arrive at an explainable grammar capable of handling “every sample we’ve seen so far drawn from an only partially observable language” ...