Re: Bison lexer

[Hans Åberg]

> On 15 Sep 2018, at 07:07, Akim Demaille <address@hidden> wrote:
> 
>> Le 31 août 2018 à 23:39, Hans Åberg <address@hidden> a écrit :
>> 
>>>>> But the final straw was when, after changing to C++ Bison, I wanted
>>>>> to switch to C++ Flex too and found this beautiful comment:
>>>>> 
>>>>> /* The c++ scanner is a mess. The FlexLexer.h header file relies on the
>>>>>  * following macro. This is required in order to pass the 
>>>>> c++-multiple-scanners
>>>>>  * test in the regression suite. We get reports that it breaks 
>>>>> inheritance.
>>>>>  * We will address this in a future release of flex, or omit the C++ 
>>>>> scanner
>>>>>  * altogether. */
>>>> 
>>>> It has been like that since the 1990s, I believe.
>>> 
>>> Even better! :(
>>> 
>>> Especially since C++ in the 1990s was totally different from modern
>>> C++, so I have no idea if anything of this comment is still
>>> relevant, or maybe even more relevant, today compared to then.
>> 
>> Indeed, very old.
> 
> So, while I totally understand Frank’s point, I’m less worried than
> he is, and use Flex’s C++ backend.

Which Flex version? It only works before 2.6.0. See:

https://stackoverflow.com/questions/34438023/openfoam-flex-yyin-rdbufstdcin-rdbuf-error

> It seems that the resources developments of Flex are scarce.  They
> easily agree on issues, but even for the most trivial ones (e.g.,
> delete three lines, https://github.com/westes/flex/issues/379),
> they ask for a patch.
> 
> But, then, who am I to discuss about the maintenance resources :-(

The issue above was discussed on their new mailing list in 2016 or so, but no 
fix yet.