From: Xavier Noria <fxn@...>
Date: 2007-08-18T21:50:26+09:00
Subject: Re: Emulating a Groovy feature?


On Aug 18, 2007, at 2:36 PM, John Wells wrote:

> Guys,
>
> There's something called Safe Navigation in Groovy (http:// 
> groovy.codehaus.org/Statements#Statements-Safenavigation) that I  
> find very appealing.
>
> So, Groovy will allow you to safely walk an object graph, even if  
> that graph has nulls in it (the walk will short circuit):
>
> def foo = null
> def bar = foo?.something?.myMethod()
> assert bar == null
>
> Is there an easy way to hack an equivalent out in Ruby?

Sure, NilClass can be reopened just fine:

   class NilClass
     def method_missing(name, *args)
       nil
     end
   end

   nil.invoices.find(5) # -> nil

Reopening NilClass is something really handy sometimes.

-- fxn