Re: Upgrading our minimum required flex version for 8.5

From: Andrew Dunstan <andrew(at)dunslane(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: Upgrading our minimum required flex version for 8.5
Date: 2009-07-02 14:35:37
Message-ID: 4A4CC5B9.5070303@dunslane.net
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Tom Lane wrote:
> I'd like to return to the project I suggested here:
> http://archives.postgresql.org/message-id/18653.1239741426@sss.pgh.pa.us
> of getting rid of plpgsql's private lexer and having it use the core
> lexer instead. This will require making the core lexer re-entrant,
> which is not possible with our oldest supported version of flex
> (2.5.4a). A look at the flex change history indicates that %reentrant
> was added in 2.5.6 but nasty bugs were being fixed up to 2.5.30;
> so the new minimum supported version would probably be 2.5.33
> (2.5.31 was kinda broken for other reasons, and there was no 2.5.32).
>
> Since 2.5.33 is now over three years old, this does not seem like an
> onerous requirement, but I thought I'd better ask if anyone has an
> objection?
>
>
>

I think it would need to be benchmarked. My faint recollection is that
the re-entrant lexers are slower.

cheers

andrew

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