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From: tmcd@panix.com (Tim McDaniel)
Newsgroups: comp.lang.perl.misc
Subject: Re: $var = do { ... }?
Date: Fri, 16 Mar 2012 15:25:10 +0000 (UTC)
Organization: Tim McDaniel's at Panix
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In article <4f633b3d$0$6845$e4fe514c@news2.news.xs4all.nl>,
Dr.Ruud <rvtol+usenet@xs4all.nl> wrote:
>On 2012-03-15 18:09, Tim McDaniel wrote:
>
>> So I have to make sure the code evaluates the desired return value as
>> the last thing in the block, like
>>
>>      my $result = do {
>>          if ($i % 2 == 0) { 'even' }
>>          elsif ($i % 3 == 0) { 'divisible by 3' }
>>          elsif ($i % 5 == 0) { 'divisible by 5' }
>>          else { 'just wrong' }
>>      };
>>
>> Is there a clever way in Perl 5 to metaphorically return early with a
>> value?
>
>That if/elsif/else of yours already does that.

Yes, I know.  I was giving an example where the desired final value is
the last thing evaluated, and then asking what I could do if that
happens not to be the case.  The next (badly contrived) example I gave
was such a case, with the 'even' case returning early and the first
"elsif" changed to an "if".

>   my $result = !$i       ? "0"
>              : !($i % 2) ? "2-fold"
>              : !($i % 3) ? "3-fold"
>              : !($i % 5) ? "5-fold"
>              : "bah";

My question was prompted bya ?: chain like that, except with much
larger and more complicated expressions, and embedded in a much larger
and much more complicated expression.  I began idly musing on
different ways it could be avoided, other than the obvious ones of
factoring it into a sub, moving it to an if-elsif-else above the much
more complicated block, and so forth.

-- 
Tim McDaniel, tmcd@panix.com