Re: #if versus #ifdef in bison.simple

[Akim Demaille]

>>>>> "Paul" == Paul Eggert <address@hidden> writes:

>> That's true for bison 1.30. For the trunk, CPP macros in
>> bison.simple become more and more stricly internal. The managing of
>> the values of these macros will be only made by Bison by options in
>> the .y file.

Paul> But doesn't this introduce some compatibility issues unless
Paul> those macros are kept the way that they are, to support programs
Paul> that use the current interface?

Yes it does.  We intend to provide backward compatibility, but to have
the documentation recommendations etc. promote the %directives instead
of #define.

Paul> YYERROR_VERBOSE itself may not be too much of a problem.  I know
Paul> of only one GNU program that #defines it, namely a2ps, and a2ps
Paul> #defines it to 1. 

Good news :)


>> Moreover, the documentation must be updated on the trunk!

Paul> And this is where my qualms come in.  Once we are talking about
Paul> changing the documented interface, we have to be careful to
Paul> avoid gratuitous changes, while of course not standing in the
Paul> way of progress.  (I know, I know, I'm sounding like a
Paul> politician.  :-)

:)

We agree.  One of our long term goals is to be able to address other
languages than C/C++.  Therefore tuning the output via #define is
wrong, we have to move towards something more Bison.

But old .y in C should have the backward compatibility they need.