From: Ilias Lazaridis <ilias@...>
Date: 2005-04-03T21:54:45+09:00
Subject: Re: [EVALUATION] - E03 - jamLang Evaluation Case Applied to Ruby

Robert Klemme wrote:
[...]
>> [i like this language *very* much]
>>
>> -
>>
>> But to understand this fully, can someone please decrypt this:
>>
>>   def meta()
>>     @meta ||= {}
>>   end
> 
> If @meta is something false (i.e. nil or false) then the expression on 
> the right hand side is evaluated and the result is assigned to @meta.  
> It's short for any of these
> 
> @meta = {} unless @meta
> @meta || (@meta = {})
> @meta or @meta = {}
> 
> {} creates a hash (synonym for Hash.new, but you can also put values 
> there like {"foo"=>"bar"}).

ok

you answer together with the other answer => i got it:

def meta()      # use of "()" is optional
   unless @meta  # if @meta == nil  ("unless" is the same as "if not")
     @meta = {}  # creates a new hash
   end
   @meta         # returns the hash
end

..

-- 
http://lazaridis.com