Horton

Re: factorial function/phase out postfix operators?

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-05-19T12:27:39Z
Lists: pgsql-hackers 
On Mon, May 18, 2020 at 10:42 AM Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
> What are the thoughts about then marking the postfix operator deprecated
> and eventually removing it?

I wrote a little bit about this last year:

http://postgr.es/m/CA+TgmoarLfSQcLCh7jx0737SZ28qwbuy+rUWT6rSHAO=B-6xdw@mail.gmail.com

I think it's generally a good idea, though perhaps we should consider
continuing to allow '!' as a postfix operator and just removing
support for any other. That would probably allow us to have a very
short deprecation period, since real-world use of user-defined postfix
operators seems to be nil -- and it would also make this into a change
that only affects the lexer and parser, which might make it simpler.

I won't lose a lot of sleep if we decide to rip out '!' as well, but I
don't think that continuing to support it would cost us much.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Remove precedence hacks no longer needed without postfix operators.

  2. Allow most keywords to be used as column labels without requiring AS.

  3. Remove support for postfix (right-unary) operators.

  4. Remove factorial operators, leaving only the factorial() function.

  5. Further refine patch for commenting operator implementation functions.