Would there be interest in a SERIOUS compile-time regex parser?

[rm]

Walter Bright wrote:
> Don Clugston wrote:
>> The question is -- would this be worthwhile? I'm really not interested
>> in making another toy.
>> It's straightforward, but tedious, and would double the length of
>> std.regexp.
>> Would the use of templates be such a turn-off that people wouldn't use
>> it?
>> Do the benefits exceed the cost?
> 
> Yes, for the following reasons:
> 
> 1) I think it would make for faster regexp's, more than just by omitting
> the compile step. That's because the bytecoded program wouldn't need to
> be interpreted.
> 
> 2) When I show the current one to people, as opposed to Eric Niebler's
> C++ one, the response is "but the D one is just a toy" with the
> implication that D is just a toy.
> 
> 3) I wrote std.regexp long before people needed or asked for it. I knew
> it would eventually become a critically needed module, and that came to
> pass. It was nice that it was there when they needed it, and the time
> passed had ensured that it was a solid piece of code.
> 
> 4) Your crafting of the current toy version was the catalyst for a big
> leap forward in D's templating system. Doing a professional one may
> expose critical problems that need to be fixed, and even if no such
> flaws are discovered, it would prove that D's TMP capabilities are up to
> scratch.
> 
> Sure, a lot of people are turned off by templates. That's one of my
> motivations for making things like associative arrays usable without
> templates. But for the people who do use templates, this can be a very
> big deal.
> 
> I think it should be in a separate module, say, regexp_static or
> something like that. Ideally, the user can switch between the two just
> by changing the module name in his code, and compare.

to code stuff like this, it would really come in handy, if there were a
compiler switch which could be set, to trace which template
instantiations are going on with which arguments.

For the moment I'm putting lot's of pragma-s in to manually trace this
stuff, but it's so verbose ;-)

roel