[ruby-talk:20911] Re: Removing singleton methods and instance variables - how ?

> -----Original Message-----
> From: Yukihiro Matsumoto [mailto:[e-mail]]
> Sent: Wednesday, September 05, 2001 1:41 PM
> To: ruby-talk ML
> Subject: [ruby-talk:20910] Re: Removing singleton methods and
> instance variables - how ?
>
>
> Hi,
>
> In message "[ruby-talk:20908] Removing singleton methods and
> instance variables - how ?"
>     on 01/09/05, "Aristarkh A Zagorodnikov" <[e-mail]> writes:
>
> |	Can anyone help me with information on possibility and ways
> of dynamically
> |removing singleton methods and instance variables from a module
> (or a class,
> |not class instance).
>
> Use Module#remove_method and Object#remove_instance_variable.
Aha! Undocumented method Object#remove_instance_variable ;)))  - at lest in
the pickaxe book.

begin code sample (test.rb) >>>>
module Test
	def Test.test
		@instance_variable = 'test'
	end

	def Test.test_variable
		remove_instance_variable '@instance_variable'
	end

	def Test.test_method
		remove_method :test
	end
end

Test.test
print 'variables: ', Test.instance_variables.inspect, "\n"
print 'methods: ', Test.singleton_methods.inspect, "\n"
Test.test_variable
print 'variables: ', Test.instance_variables.inspect, "\n"
Test.test_method
print 'methods: ', Test.instance_methods.inspect, "\n"

<<<< end code sample

begin run sample >>>>
root@is:/home/xm# ruby test.rb
variables: ["@instance_variable"]
methods: ["test_method", "test_variable", "test"]
variables: []
test.rb:11:in `remove_method': method `test' not defined in Test (NameError)
        from test.rb:11:in `test_method'
        from test.rb:20
<<<< end run sample

So remove_method does not work for singleton methods ... we should have
remove_singleton_method I believe.
Also, why remove_instance_variable accepts string which must start from '@'
? I believe it should take a symbol (:instance_variable in my case), and all
methods which return list (like instance_methods, instance_variables,
public_instance_methods and all that family) should return symbols instead
of strings (someone suggested this before I believe).

Aristarkh A Zagorodnikov, Lead Programmer, W3D Group
http://www.w3d.ru /// [e-mail] /// ICQ UIN 36987938