From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Johnston <david.g.johnston@gmail.com>
cc: "pgsql-docs@postgresql.org" <pgsql-docs@postgresql.org>
Subject: Re: Add Optional Variadic Invocation Explanation to 35.4.5
 (xfunc-sql)
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Comments: In-reply-to David Johnston <david.g.johnston@gmail.com>
 message dated "Fri, 19 Dec 2014 14:33:19 -0700"
Date: Sun, 21 Dec 2014 15:35:36 -0500
Message-ID: <15559.1419194136@sss.pgh.pa.us>
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Sender: pgsql-docs-owner@postgresql.org

David Johnston <david.g.johnston@gmail.com> writes:
> This:
> http://www.postgresql.org/docs/9.4/static/xfunc-sql.html
> Describes how to invoke a function defined with VARIADIC with an actual
> array as input instead of supplying ONE-or-more individual arguments to the
> call.

Right, and it does specifically say that there must be at least one
actual argument matching the VARIADIC parameter.  Still, an example
to clarify that isn't a bad idea.

> AFAICS the only way to get the called function to see an empty array is to
> call it like:
> SELECT varchar('text fixed 1', VARIADIC ARRAY[]::text[])
> While this is a logical solution to the problem, given the above knowledge,
> it would be nice if both points were made explicitly in the documentation
> in the section linked above.

I did not like your proposed wording, as it seemed to complicate matters
unduly by treating two independent points in the same para.  I went with
just adding a separate para instead:
http://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=699300a146c04e207a8fdec407538cdf5368fde5

			regards, tom lane


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