Re: font-lock is broken

[Richard M. Stallman]

    The most common such problem by far is when a regexp hits a pathological
    exponential-matching behavior.  I wish we'd fix that one instead.

It would be good to fix that, but how?  It is a consequence of the
algorithm, and even recognizing these cases would seem to be a hard
problem.

    Also, they're only painful because of Emacs's lack of NMI.

What is NMI?

      E.g. when C-g is pressed, record the time, and if a C-g
    is pressed again 2 seconds later and the first hasn't been processed yet,
    then ignore the inhibit-quit flag (i.e. set it back to nil).

I don't understand the suggestion clearly.  What would it do if the
second C-g is less than two seconds later?  What would it do if the
second C-g is more than two seconds later?