From: Rein Henrichs <reinh@...>
Date: 2010-06-15T08:30:05+09:00
Subject: Re: shorthand

On 2010-06-14 15:41:09 -0700, Rick DeNatale said:

> On Mon, Jun 14, 2010 at 5:48 PM, Roger Pack <rogerpack2005@gmail.com> wrote:
>> I read this once:
>> 
>> Operator ||= can be shorthand for code like:
>> �x = "(some fallback value)" unless respond_to? :x or x
>> 
>> How would that look like exactly, in shorthand, any guesses?
> 
> 
> I don't know where you read that, but it has no basis in reality.  The
> semantics of ||= have nothing to do with whether or not a method
> exists.
> 
> The closest translation of
> 
> x ||= y
> 
> (x || x = y)
> 
> This is close, except that it will blow up if x isn't already defined.
> 
> another alternative might be
> 
> (defined? x) ? (x || x = y) : y
> 
> Which avoids the problem when x isn't defined, but isn't exactly what
> the 'compiled' ruby code does, whether that 'code' is YARV 'byte
> codes' or an AST in MRI pre 1.9
> 
> --
> Rick DeNatale
> 
> Blog: http://talklikeaduck.denhaven2.com/
> Github: http://github.com/rubyredrick
> Twitter: @RickDeNatale
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Rick,

Can we combine the contents of the thousands of messages explaining the 
behavior of <operator>= into a blog post and just start referencing it? 
Oh wait, didn't you do that? ;)

We need a FAQ :D

-- 
Rein Henrichs
http://puppetlabs.com
http://reinh.com