Re: Erroring out on parser conflicts

On 3 Dec 2008, at 03:32 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Bruce Momjian <bruce(at)momjian(dot)us> writes:
>> FYI, this is going to make it hard for developers to test CVS changes
>> until they get their grammar cleaned up; perhaps add a comment on
>> how
>> to disable the check?
>
> Well, the point is that their grammar changes are broken if that check
> fails, so I'm not sure what the value of "testing" a known-incorrect
> grammar might be. It wouldn't necessarily act the same after being
> fixed.
>

Well surely the c code the parser invokes will behave the same. A lot
of c hackers are not bison grammar hackers. Even many of us former
bison grammar hackers are way rusty. There have been a number of times
when someone has posted an otherwise working patch with a grammar
conflict you fixed

Bruce surely nobody would object if you posted a path to add a
comment. People would of course quibble with the wording but that's
just par for the course.

Perhaps something like "postgres jas a policy of maintaining zero
parser conflicts. If you disable this for testing make sure you re-
enable it and eliminate any conflicts. Or post to -hackers asking for
advice"

I'm not sure where to put a comment pointing them to the %expected
line though. What does the error look like if they violate it?

> regards, tom lane
>
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