I admit significant bias toward liking PCRE regexps much better than emacs, if no no other reason that when I type a '(' I pretty much always want a grouping operator. And, of course, \w and similar are SO much more convenient than the other equivalents.
But it would be crazy to expect to change the internals of emacs, of course. But it should be possible to convert from a PCRE experssion to an emacs expression, I'd think, and do all the needed conversions so I can write:
(defun my-super-regexp-function ...
(search-forward (pcre-convert "__\\w: \d+")))
(or similar).
Anyone know of a elisp library that can do this?
Edit: Selecting a response from the answers below...
Wow, I love coming back from 4 days of vacation to find a slew of interesting answers to sort through! I love the work that went into the solutions of both types.
In the end, it looks like both the exec-a-script and straight elisp versions of the solutions would both work, but from a pure speed and "correctness" approach the elisp version is certainly the one that people would prefer (myself included).