Re: [HACKERS] scanner/parser for FOREIGN KEY - Mailing list pgsql-hackers

From wieck@debis.com (Jan Wieck)
Subject Re: [HACKERS] scanner/parser for FOREIGN KEY
Date
Msg-id m1259JN-0003kGC@orion.SAPserv.Hamburg.dsh.de
Whole thread Raw
In response to Re: [HACKERS] scanner/parser for FOREIGN KEY  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:

> 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.

    The solution, Thomas suggested, would work too. It will avoid
    any  portability  issues   by   making   analyze.c   slightly
    complexer,  but  that's  already  complex  enough by juggling
    around with multiple lists, so one more  hack  there  doesn't
    count.

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

    I'm fine with either solution. IMHO it's just a MUST BE THERE
    before going BETA, since it affects the syntax of  the  query
    language.


Jan

--

#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me.                                  #
#========================================= wieck@debis.com (Jan Wieck) #

pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: [HACKERS] scanner/parser for FOREIGN KEY
Next
From: Thomas Lockhart
Date:
Subject: Re: date/time type changes