Re: Bison lexer

[Hans Åberg]

> On 1 Sep 2018, at 00:12, Frank Heckenbach <address@hidden> wrote:
> 
> Hans Åberg wrote:
> 
>>> I haven't used gcc-8 yet, but how is this relevant? If anything, I
>>> expect newer gcc versions to produce more warnings (usually useful)
>>> which flex might also suffer from.
>> 
>> Maybe the Flex lexers errors is due to using C89 to compile it or something.
> 
> No, the warnings seemed legit.

It uses "register" which has been deprecated in C++17.

>>> Interesting, thanks. Fortunately, my REs are not so complex, so the
>>> bug you reported won't affect me and lexing speed is not so
>>> important for me, so (at least for now) I can just use the library
>>> as is. But if I ever need something more sophisticated, I'll keep
>>> this in mind.
>> 
>> If that is what you are using, note that it is recursive, so the function 
>> stack might overflow. But perhaps the rewrite it someday.
> 
> I don't think my lexing REs should cause much recursion. No nested
> repetitions or such.

It is in the backtracking, which it does instead of a DFA iteration, in the GCC 
regex library, that is. Some example in the links I gave illustrate that.