Re: Re: UNION JOIN vs UNION SELECT - Mailing list pgsql-hackers

From Andrew Selle
Subject Re: Re: UNION JOIN vs UNION SELECT
Date
Msg-id 20000828220945.A8170@upl.cs.wisc.edu
Whole thread Raw
In response to Re: Re: UNION JOIN vs UNION SELECT  (Chris <chrisb@nimrod.itg.telstra.com.au>)
List pgsql-hackers
> > 
> > That's exactly the solution I'm proposing.  However, it's pretty painful
> > to make the lexer do it directly (consider intervening comments, for
> > example)
> 
> Comments are a pain in the parser. What if something prior to the lexer
> filtered out comments before either the lexer or parser could see them?
> Would it be as easy as s/--.*// before the lexer?

It probably wouldn't be that simple, but I do think that the solution
is sound.  Such a design is recommended by the Dragon book and has
the benefit of simplifying both the lexer and the parser.

-Andy


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