prolog-mode uses bad syntax for _

[Miles Bader <miles.bader@necel.com>]

prolog-mode changes the syntax of _ to be a word-constituent, which I
suspect is the wrong thing.  It does not interact well with users'
editing intuitions.

Most old modes that I've seen do this, do it only so that they can use
\< and \> in regexps (to match things like keywords) without getting
false positives adjacent to an underscore.  Nowdays we can just change
the regexps to use \_< and \_> instead, so _ should be able to have a
more normal syntax.

Anyone see any problems with changing prolog-mode in this fashion?

Thanks,

-Miles

-- 
If you can't beat them, arrange to have them beaten.  [George Carlin]