Scanner/Parser question - what does _P imply?

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.

Ahhh... now it's clear.

Thanks.

-- Korry

<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.

regards, tom lane

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

--
#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me. #
#================================================== JanWieck@Yahoo.com #

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?

I can't seem to put it down :-)

From the back cover:

A rollercoaster ride of passion, heart-stopping adventures, and
gut-wrenching laughs ... every bit as thrilling as copyfuncs.c,
more of a tearjerker than bufmgr.c, and as deliciously naughty
as MySQL's item.cc.

Get gram.y, in stores now (or order at Amazon.com, delivered in a plain
brown wrapper).

-- Korry