Re: Interesting problem with PostgreSQL grammar ...

[Laurence Finston]

On Mon, 22 Nov 2004, Hans Aberg wrote:

> You do not say what shift/reduce conflicts you get, so it is hard to follow.
> Please make sure to always include pertinent info.
>
> But a casual look suggests that you may get a conflicts between two empty
> rules. If that is so, you need to rewrite your grammar.
>

My experience bears this out.  One of the advantages of using the approach
I described in my last posting is that it reduces the number of empty
rules.  It also makes it possible to have use options in any order in the
input, and to use options multiple times.  I won't claim that it's not
possible to do this in the normal way, but I don't know off the top of my
head how to do it.  My approach does involve some overhead, so I don't
always use it.  I'm past the point of worrying about shift-reduce
conflicts;  if resolving them by shifting works, I don't care.

Laurence