Message-ID: <42D41DF3.6050702@dunslane.net>
Date: Tue, 12 Jul 2005 15:45:55 -0400
From: Andrew Dunstan <andrew@dunslane.net>
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To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Michael Fuhr <mike@fuhr.org>, pgsql-hackers@postgresql.org
Subject: Re: PL/Perl list value return causes segfault
References: <20050712130452.GA84564@winnie.fuhr.org>
	<42D41319.70107@dunslane.net>
	<20050712193303.GA14060@alvh.no-ip.org>
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Alvaro Herrera wrote:

>On Tue, Jul 12, 2005 at 02:59:37PM -0400, Andrew Dunstan wrote:
>
>  
>
>>Note that all plperl functions are called in scalar context, and it is 
>>always wrong to return a list (as opposed to a listref). In fact, the 
>>value received might surprise you even if it worked (it would be the 
>>value of the last member of the list).
>>    
>>
>
>Hmm, I don't know if it's feasible to do in Perl, but maybe check
>whether the function wants to return something in list context and throw
>an appropiate error message?
>
>  
>

In perl, if there is any ambiguity it is the called function that is 
responsible for checking, not the caller. See "perldoc -f wantarray". 
PLPerl explicitly passed G_SCALAR as a flag on all calls to plperl 
routines. So returning a list is a case of pilot error.

cheers

andrew