From: Gregory Brown <gregory.t.brown@...>
Date: 2008-08-01T02:53:10+09:00
Subject: Re: super with block

On Thu, Jul 31, 2008 at 1:47 PM, Lou Zell <lzell11@gmail.com> wrote:
>> your problem has nothing to do with passing the block along in gsub!
>>>>> s = NString.new("hi")
>> guess what s is here?
>> If you guessed "", you guessed correctly
>
> Wait, why would s be empty?  I can use Nstring.new just like String.new
>
>>> class Nstring < String
>>> end
> => nil
>>> n = Nstring.new("hi")
> => "hi"
>>> puts n
> hi

Same here:

seltzer:~ sandal$ ruby -v
ruby 1.8.6 (2008-06-20 patchlevel 230) [i686-darwin8.11.1]
seltzer:~ sandal$ irb
>> class NString < String
>> end
=> nil
>> n = NString.new("hi")
=> "hi"
>> puts n
hi

That having been said, I generally avoid sub-classing core Ruby
objects because I think some of them use optimizations that cause
internal C methods to be called rather than the methods of a subclass,
resulting in strange behaviour.  That having been said, I don't know
that I've ever seen it in practice.  Does anyone have an example of
this, or am I just being paranoid?

-greg