🚀 go-pugleaf

I'm looking for a tags package that doesn't read in the whole file.
Over at work, we have a 4 MB tags file that gets read in on a tags
request, which slows the machine down beyond recognition, and also
prevents our pmake from working as well as it might.  I've done
preliminary work on getting M-. to work (by doing a grep -i on the
tags file and piping that into the buffer, after which a normal tag is
done on it), but I can't seem to be able to get M-, to work, so I'd
appreciate any pointers to a version of tags.el that'll work.

If not, could someone who knows how tags work send me mail and explain
how all that tags-loop-continue stuff work?

Thanks,
Piaw
Dyslexics of the world, untie!