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Message-ID: <45B9071B.9060806@Yahoo.com>
Date: Thu, 25 Jan 2007 14:38:03 -0500
From: Jan Wieck <JanWieck@Yahoo.com>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: korryd@enterprisedb.com, pgsql-hackers@postgresql.org
Subject: Re: Scanner/Parser question - what does _P imply?
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	<27181.1169134508@sss.pgh.pa.us>
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On 1/18/2007 10:35 AM, Tom Lane wrote:
> <korryd@enterprisedb.com> writes:
>> Many of the keywords listed in keywords.c are defined with symbolic
>> names that end in '_P' (underscore P).
>> What differentiates those keywords from the other keywords?  What does
>> the 'P' stand for?
> 
> P = Parser.  The reason for the _P is just to avoid conflicts with
> other definitions of the macro name, either in our own code or various
> platforms' header files.  We haven't been totally consistent about it,
> but roughly speaking we've stuck _P on when it was either known or
> seemed likely that there might be a conflict.
> 
> Some years ago there was discussion of consistently P-ifying *all* those
> macros, but it didn't get done; I think Thomas or somebody objected that
> it would make gram.y needlessly harder to read.

Are there many people who read gram.y on a regular base?


Jan

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