compile-time regex redux

[kris]

Bill Baxter wrote:
> Andrei Alexandrescu (See Website For Email) wrote:
> 
>> kenny wrote:
>>
>>> Walter, I don't hate regex -- I just don't use it. It seems to me 
>>> that to figure out regex syntax takes longer than writing quick 
>>> for/while statements, and I usually forget cases in regex too...
>>
>>
>> I think this is an age-old issue: if you don't know something, you 
>> find it harder to do things that way. The telling sign is that people 
>> who know _both_ simple loops and regexes do use regexes, and as a 
>> consequence are way more productive at a certain category of tasks.
> 
> 
> Hmm.  More productive, probably.   Writing better code?  Not clear.  I 
> would guess that in many cases the results are not as easy to maintain 
> as non-regexp code.
> 
> Anyway, I think the question is whether compile-time regexp is really 
> the right level of abstraction to be targeting.  Wouldn't it be 
> infinitely better to have the compile-time code facilities be so good 
> that you could just write a regexp parser as a compile-time D library?
> 
> I mean what is regexp, but a particular DSL?  If the new facilities are 
> trying to make DSL's easier to create, regexp is a great target DSL.  So 
> what compile-time language facilities do you need to implement an 
> efficient and clean compile-time regexp library?
> 
> It would be nice if we could write more-or-less generic D code with a 
> few compile time restrictions.  For instance you can write any function 
> you want that takes only const values as arguments and returns a const 
> value, and refers to only global const values and other such const-only 
> functions.
> 
> --bb

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