From: tamouse mailing lists <tamouse.lists@...>
Date: 2013-02-13T12:36:23+09:00
Subject: Re: elegant way to determine if something is defined

On Sat, Feb 9, 2013 at 9:20 PM, Adam Prescott <adam@aprescott.com> wrote:
>> Object.defined?('a')
>
> defined?(a) #=> nil
> b = a + 1 #=> NameError
> a = 1
> defined?(a) #=> "local-variable" (strings are truthy)
>
> However, relying on defined?(a) to check for local variables is
> probably a code smell: they're local variables, why isn't the code
> just written properly? What's the problem you're trying to solve?
>

You've pretty much hit the nail on the head there -- legacy code, much
of it not very well thought out, etc. Some of this is debugging
(de-smelling? SANITIZING!)