Re: :PgSQL: More Queestions - Mailing list pgsql-interfaces

From Tim Bunce
Subject Re: :PgSQL: More Queestions
Date
Msg-id 20021121092316.GF381@dansat.data-plan.com
Whole thread Raw
In response to Re: :PgSQL: More Queestions  (David Wheeler <david@wheeler.net>)
Responses Re: :PgSQL: More Queestions  ("Jeff Urlwin" <jurlwin@bellatlantic.net>)
List pgsql-interfaces
On Wed, Nov 20, 2002 at 10:30:00PM -0800, David Wheeler wrote:
> On Wednesday, November 20, 2002, at 06:53  AM, Tim Bunce wrote:
> 
> >>But if I change it (as I'm seriously considering, in light of
> >>PostgreSQL 7.3's support for prepared statements), I'll probably do no
> >>parsing for comments.
> >
> >I think that would be a bad move.
> 
> Yes, your last post makes very clear why. Thanks.
> 
> >If it's seen the start of a string ("..." or '...') then it just
> >keeps copying the string till it finds the same type of quote
> >character to mark the end of the string. The 'fiddly bit in the
> >middle' is handling backslashes used to escape quote chars in the
> >middle of the string:  "...\"..." and "...\\" (odd vs even number).
> 
> Seems rather opaque. Maybe I'm just reflecting my C-newbieness, but why 
> wouldn't this work as well? Borrowing a bit from DBD::ODBC here (but 
> allowing for both kinds of escaping of the quote characters):
> 
>         if (*src == '"' || *src == '\'') {
>             if (!in_literal) {
>                 literal_ch = *src;
>                 in_literal = 1;

No need for in_literal as literal_ch can serve as a flag as well.

>             } else {
>                 if (*src == literal_ch && *(src-1) != '//'
>                     && *(src-1) != literal_ch) {
>                     in_literal = 0;
>                 }
>             }
>         }

Can't distinguish between"....\\\\"    - final double quote ends the string"...\\\\\"    - final double quote is
escapedand string continues...
 

If the original code isn't broken it doesn't need fixing, maybe
just commenting.

Tim.


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