Re: suggested warning about perl nested named subroutines

On Tue, Oct 11, 2005 at 08:40:21PM -0400, Andrew Dunstan wrote:
>
> I propose to add the following to the plperl docs, following recent
> problems.
>
> comments?

Examples of each and how they'd break would be good.

Cheers,
D
>
> cheers
>
> andrew
>
>
> Index: plperl.sgml
> ===================================================================
> RCS file: /cvsroot/pgsql/doc/src/sgml/plperl.sgml,v
> retrieving revision 2.45
> diff -c -r2.45 plperl.sgml
> *** plperl.sgml 24 Aug 2005 19:16:49 -0000 2.45
> --- plperl.sgml 12 Oct 2005 00:36:33 -0000
> ***************
> *** 53,64 ****
> # PL/Perl function body
> $$ LANGUAGE plperl;
> </programlisting>
> ! The body of the function is ordinary Perl code. A PL/Perl function must
> always return a scalar value. You can return more complex structures
> (arrays, records, and sets) by returning a reference, as discussed
> below.
> Never return a list.
> </para>
>
> <para>
> The syntax of the <command>CREATE FUNCTION</command> command requires
> the function body to be written as a string constant. It is usually
> --- 53,76 ----
> # PL/Perl function body
> $$ LANGUAGE plperl;
> </programlisting>
> ! The body of the function is ordinary Perl code. In fact, the PL/Perl
> ! glue code wraps it inside a Perl subroutine. A PL/Perl function must
> always return a scalar value. You can return more complex structures
> (arrays, records, and sets) by returning a reference, as discussed
> below.
> Never return a list.
> </para>
>
> + <note>
> + <para>
> + The use of named nested subroutines is dangerous in Perl,
> especially if
> + they refer to lexical variables in the enclosing scope. Because
> a PL/Perl
> + function is wrapped in a subroutine, any named subroutine you
> create will
> + be nested. In general, it is far safer to create anonymous
> subroutines
> + which you call via a coderef. See the <literal>perldiag</literal>
> + man page for more details.
> + </para>
> + </note>
> +
> <para>
> The syntax of the <command>CREATE FUNCTION</command> command requires
> the function body to be written as a string constant. It is usually
>
>
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