wieck@debis.com (Jan Wieck) writes:
>     we  still need the enhancement of the scanner/parser combo to
>     enable FOREIGN KEY specification as  column  constraint  (the
>     due to shift/reduce disabled NOT DEFERRABLE part).
>     IMHO this must be done before going into BETA.  As discussed,
>     a little token lookup/queueing between lex and  yacc  can  do
>     the  trick. I'd like to add a slightly generic method for it,
>     so the lookahead function can be reused if we  sometimes  get
>     trapped again with a similar problem.
>     Do we have a consensus to implement it that way now?

AFAIR that was the only concrete solution offered.  I think Thomas
wanted to look into whether he could tweak the grammar to avoid the
problem without lookahead, but he hasn't produced any results ---
and I misdoubt that a fix done that way will be any cleaner than
inserting a lexer lookahead interface.

In short, it's fine by me but I dunno if Thomas has signed on yet.

			regards, tom lane

Mon, 03 Jan 2000 10:21:46 -0500
Tom Lane <tgl@sss.pgh.pa.us>
Re: [HACKERS] scanner/parser for FOREIGN KEY 
> AFAIR that was the only concrete solution offered.  I think Thomas
> wanted to look into whether he could tweak the grammar to avoid the
> problem without lookahead, but he hasn't produced any results ---
> and I misdoubt that a fix done that way will be any cleaner than
> inserting a lexer lookahead interface.
> In short, it's fine by me but I dunno if Thomas has signed on yet.

I glanced at it, but have not had a chance to dive in. There had been
so many changes to the parser code while I was off playing with outer
join syntax that I decided to start over (lots of what I had done
needed to be cleaned up anyway).

I hope to get back to development within a few days, but in the
meantime my parser is re-broken and I haven't yet fixed Jan's parts. I
hate to be holding up Jan, but otoh I hate to see us having to use a
new techique for parsing if the usual ones can be made to work...

                    - Thomas

-- 
Thomas Lockhart				lockhart@alumni.caltech.edu
South Pasadena, California

Mon, 03 Jan 2000 15:51:12 +0000
Thomas Lockhart <lockhart@alumni.caltech.edu>
Re: [HACKERS] scanner/parser for FOREIGN KEY
> > AFAIR that was the only concrete solution offered.  I think Thomas
> > wanted to look into whether he could tweak the grammar to avoid the
> > problem without lookahead, but he hasn't produced any results ---
> > and I misdoubt that a fix done that way will be any cleaner than
> > inserting a lexer lookahead interface.
> > In short, it's fine by me but I dunno if Thomas has signed on yet.
> 
> I glanced at it, but have not had a chance to dive in. There had been
> so many changes to the parser code while I was off playing with outer
> join syntax that I decided to start over (lots of what I had done
> needed to be cleaned up anyway).
> 
> I hope to get back to development within a few days, but in the
> meantime my parser is re-broken and I haven't yet fixed Jan's parts. I
> hate to be holding up Jan, but otoh I hate to see us having to use a
> new techique for parsing if the usual ones can be made to work...

Agreed.  Maybe Thomas and I can get on the phone and hammer out a fix.

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Mon, 3 Jan 2000 11:04:28 -0500 (EST)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: [HACKERS] scanner/parser for FOREIGN KEY