From: Patrick Bennett <patrick.bennett@...>
Date: 2002-08-13T08:37:46+09:00
Subject: Re: Q) about singleton methods and access control



Christoph wrote:

>"Bennett, Patrick" wrote
>....
>  
>
>>Maybe I'm missing something here, but.... I called it from an instance.
>>You saw the 'testObj = A.new' - right?
>>    
>>
>
>No, the call is on the  ``class Level'' -  for example I get
>
No it's not.  I was calling testObj.xxxxx -  that's definitely an 
"instance" level call.  :\
Arrgggh....

>---
>in class_meth self = A with self.type = Class
>in class_meth self is still = A with self.type = Class
>in an_instance_method  self = #<A:0x2789ad8> with self.type = A
>---
>
>when running
>
>---
>class A
>   def A.class_meth
>        puts "in class_meth self = #{self} with self.type = #{type}"
>        obj = A.new
>        puts "in class_meth self is still = #{self} with self.type = #{type}"
>   end
>

This example makes no sense to me at all.  What exactly are you testing? 
 Why would you think 'self' would change in the middle of a method?
Why aren't you calling an instance method of obj (that you created in 
the singleton method)?  That's the whole point of this issue.  The fact that
singleton's can't create an >instance< and call that >instance's< 
private >instance< method (as in C++) - since the singleton is 
technically a member of the class, and should
be able to workin within its security constraints.  Apparently, Ruby 
just doesn't support it.   Fine, I can live with it.  I'm still curious 
as to 'why' though - since it's seems
to be an odd ommision.

>  # versus
>   def an_instance_method
>        puts "in an_instance_method  self = #{self} with self.type = #{type}"
>    end
> end
>
>A.class_meth
>inst = A.new
>inst.an_instance_method
>---
>
>  
>
>>That works(!)... but why?  (scratching head)
>>Why does send bypass access control?
>>    
>>
>
>Well it does, so just use it ...
>
I will..... thanks.  :>
(even though it seems a strange hack)