From: Ryan Leavengood <leavengood@...>
Date: 2006-05-23T00:59:27+09:00
Subject: Re: initializing instance variables in a module

module Foo
   def add_stuff(key, stuff)
     (@foo_the_stuff ||= {})[key] = stuff
   end
end

If @foo_the_stuff is null, it will be initialized to an empty hash,
otherwise the existing value will be used. I consider this use of ||=
to be a Ruby idiom.

Ryan

On 5/22/06, Jeff Rose <rosejn@gmail.com> wrote:
> Have a module:
>
> Module Foo
>    def add_stuff(key, stuff)
>      @foo_the_stuff[key] = stuff
>    end
> end
>
> class Bar
>    include Foo
> end
>
> Is there a standard or correct way to initialize @foo_the_stuff in this
> example?  Should the add_stuff method check whether the variable has
> been initialized every time, or should this be done by implementing a
> callback like append_features or included?  (That's how I'd want to do
> it, but it's not clear which or how...)
>
> Thanks,
> Jeff