From: Rob Biedenharn <Rob@...>
Date: 2007-07-26T04:38:47+09:00
Subject: Re: opposite of [thing].flatten

On Jul 25, 2007, at 3:10 PM, Phlip wrote:
> Ruby-ists:
>
> We all know this clever idiom to turn a variable that might be an  
> Array into
> one known to be an Array:
>
>   thing = [thing].flatten
>
> That saves a lot of if statements to permit thing's type to overload.
>
> What is the opposite (clever) operation? How to turn a list of one  
> item into
> one item, and a list of zero items into nil, but pass thru the list  
> of many
> items?
>
> -- 
>  Phlip
>  http://www.oreilly.com/catalog/9780596510657/
>  ^ assert_xpath
>  http://tinyurl.com/23tlu5  <-- assert_raise_message

Except for the fact that it is deprecated, use .to_a:

irb(main):001:0> nil.to_a
=> []
irb(main):002:0> "one".to_a
=> ["one"]
irb(main):003:0> [1,2,3].to_a
=> [1, 2, 3]

------------------------------------------------------------ Object#to_a
      obj.to_a -> anArray
------------------------------------------------------------------------
      Returns an array representation of _obj_. For objects of class
      +Object+ and others that don't explicitly override the method, the
      return value is an array containing +self+. However, this latter
      behavior will soon be obsolete.

         self.to_a       #=> -:1: warning: default `to_a' will be  
obsolete
         "hello".to_a    #=> ["hello"]
         Time.new.to_a   #=> [39, 54, 8, 9, 4, 2003, 3, 99, true, "CDT"]


-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com