From jeremygwa at hotmail.com  Thu Aug  7 13:56:35 2008
From: jeremygwa at hotmail.com (Jer A)
Date: Thu, 7 Aug 2008 13:56:35 -0700
Subject: [VPM] passing parameters to sub ref then execute
Message-ID: <BLU137-W481AA59AE647388514C729B2750@phx.gbl>


if this is how to exec a subroutine ref, without params .eg $o = &$c;

how do I pass parameters to it.

thanks in advance for your help.

Jeremy A


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From darren at darrenduncan.net  Thu Aug  7 14:21:50 2008
From: darren at darrenduncan.net (Darren Duncan)
Date: Thu, 07 Aug 2008 14:21:50 -0700
Subject: [VPM] passing parameters to sub ref then execute
In-Reply-To: <BLU137-W481AA59AE647388514C729B2750@phx.gbl>
References: <BLU137-W481AA59AE647388514C729B2750@phx.gbl>
Message-ID: <489B676E.5030003@darrenduncan.net>

Jer A wrote:
> if this is how to exec a subroutine ref, without params .eg $o = &$c;
> 
> how do I pass parameters to it.
> 
> thanks in advance for your help.
> 
> Jeremy A

I would spell that like this:

   $o = &{$c}();

And then put the arguments between the parenthesis as usual.

-- Darren Duncan

From Peter at PSDT.com  Thu Aug  7 14:26:41 2008
From: Peter at PSDT.com (Peter Scott)
Date: Thu, 07 Aug 2008 14:26:41 -0700
Subject: [VPM] passing parameters to sub ref then execute
In-Reply-To: <489B676E.5030003@darrenduncan.net>
References: <BLU137-W481AA59AE647388514C729B2750@phx.gbl>
	<489B676E.5030003@darrenduncan.net>
Message-ID: <6.2.3.4.2.20080807142503.02d53ab0@mail.webquarry.com>

At 02:21 PM 8/7/2008, Darren Duncan wrote:
>Jer A wrote:
>>if this is how to exec a subroutine ref, without params .eg $o = &$c;
>>how do I pass parameters to it.
>>thanks in advance for your help.
>>Jeremy A
>
>I would spell that like this:
>
>   $o = &{$c}();
>
>And then put the arguments between the parenthesis as usual.

I write

         $o = $c->();

in both cases.  Either there are arguments between the parentheses or 
not.  Preferring the arrow operator for dereferencing is a bestpractice IMHO.


-- 
Peter Scott
Pacific Systems Design Technologies
http://www.perldebugged.com/
http://www.perlmedic.com/



From darren at darrenduncan.net  Thu Aug  7 17:42:33 2008
From: darren at darrenduncan.net (Darren Duncan)
Date: Thu, 07 Aug 2008 17:42:33 -0700
Subject: [VPM] passing parameters to sub ref then execute
In-Reply-To: <6.2.3.4.2.20080807142503.02d53ab0@mail.webquarry.com>
References: <BLU137-W481AA59AE647388514C729B2750@phx.gbl>	<489B676E.5030003@darrenduncan.net>
	<6.2.3.4.2.20080807142503.02d53ab0@mail.webquarry.com>
Message-ID: <489B9679.5010802@darrenduncan.net>

Peter Scott wrote:
> At 02:21 PM 8/7/2008, Darren Duncan wrote:
>> Jer A wrote:
>>> if this is how to exec a subroutine ref, without params .eg $o = &$c;
>>> how do I pass parameters to it.
>>> thanks in advance for your help.
>>> Jeremy A
>>
>> I would spell that like this:
>>
>>   $o = &{$c}();
>>
>> And then put the arguments between the parenthesis as usual.
> 
> I write
> 
>         $o = $c->();
> 
> in both cases.  Either there are arguments between the parentheses or 
> not.  Preferring the arrow operator for dereferencing is a bestpractice 
> IMHO.

Yes, that works too.

Come to think of it, my example was derived from a somewhat different 
situation, when I wanted to invoke a package-qualified routine that wasn't 
a method.

Something closer to my source example is:

   my $result = &{$mypkgname->can( 'myfunc' )}(...);

This is for when I wanted the semantics of "MyPkg::myfunc(...)" but the 
name of MyPkg was in a variable.

So my example was mis-applied here; when $c is already a subroutine ref, 
then Peter's syntax is better.

-- Darren Duncan