bug#192: regexp does not work as documented

[Stefan Monnier]

> As for making hi-lock-mode detect whether or not a regexp is multi-line,
> isn't that a computationally non-trivial problem?

Well, you can turn the regexp into a DFA, then take the ".*\n.+" regexp,
turn it into another DFA, take the intersection of the two DFAs, and if
it's empty you know your regexp can never match a multiline element.


        Stefan