Akim Demaille <akim@lrde.epita.fr> writes:
> It is for the same reasons that I would recommend not using associativity directives (%left, %right, %nonassoc) where
associativityplays no role: %precedence is made for this. But it was introduced in Bison 2.7.1 (2013-04-15), and I
don'tknow if requiring it is acceptable to PostgreSQL.
2013? Certainly not. We have a lot of buildfarm critters running
older platforms than that. I believe our (documented and tested)
minimum version of Bison is still 1.875. While we'd be willing
to move that goalpost if there were clear benefits from doing so,
I'm not even convinced that %precedence as you describe it here
is any improvement at all.
regards, tom lane