From: Thufir <hawat.thufir@...>
Date: 2008-02-22T21:33:22+09:00
Subject: Re: ||= [] idiom

On Wed, 20 Feb 2008 07:21:15 +0900, MenTaLguY wrote:

> I sometimes do this sort of thing:
> 
>  ( @categories[resource.tag] ||= [] ) << resource
> 
> Although this might possibly be more readable:
> 
>  category = ( @categories[resource.tag] ||= [] ) category << resource
> 
> Often it can make sense to factor the ||= portion into a separate
> method:
> 
>  def category_for(tag)
>    @categories[tag] ||= []
>  end
> 
>  # ...
> 
>    category_for(resource.tag) << resource
> 
> -mental
>

What's the real-world application of this?



thanks,

Thufir