On 6/14/07, Giles Bowkett <gilesb@[...].com>  wrote:
>  I want to write a module which, when included in another module,
>  destroys every method of a class in that module. I realize this isn't
>  really a very useful thing to do, but I want to do it to see if it can
>  be done. I want to actually include the module and have it replace all
>  existing methods of this class with just one method.
> 
>  In Python you can change an object's class in the middle of your
>  program by reassigning its magical __class__ variable. That would be a
>  very simple way to implement this idea. Doesn't seem possible here,
>  though.
> 
>  Here's an attempt which failed:
> 
>  >> class Muppet
>  >>   def show
>  >>     "it's the muppet show!"
>  >>     end
>  >>   end
>  => nil
>  >> kermit = Muppet.new
>  => #<Muppet:0x123129c>
>  >> kermit.show
>  => "it's the muppet show!"
>  >> class Muppet
>  >>   remove_method(:show)
>  >>   end
>  => Muppet
>  >> kermit.show
>  NoMethodError: undefined method `show' for #<Muppet:0x123129c>
>          from (irb):36
>          from :0
> 
>  So far so good, but I want to get rid of *every* method. Doing what I
>  just did programmatically, iterating over all available methods,
>  that's the thing which still eludes me.
> 
>  None of these attempts work:
> 
>  >> kermit.methods.each{|m| class << Muppet ; (remove_method(m)) ; end}
>  NameError: undefined local variable or method `m' for #<Class:Muppet>
>          from (irb):43
>          from (irb):43:in `each'
>          from (irb):43
>          from :0
>  >> kermit.methods.each{|m| class Muppet; remove_method(m.to_sym) ; end}
>  NameError: undefined local variable or method `m' for Muppet:Class
>          from (irb):44
>          from (irb):44:in `each'
>          from (irb):44
>          from :0
>  >> kermit.methods.each{|m| Muppet.class_eval(remove_method(m))}
>  NoMethodError: undefined method `remove_method' for #<Object:0x349f4>
>          from (irb):45
>          from (irb):45:in `each'
>          from (irb):45
>          from :0
> 
>  I have to admit, it's not necessarily a bad thing if this task proves
>  impossible, but I feel like it *should* be possible.

kermit.class.instance_methods(false).each{|m|
Muppet.instance_eval("remove_method #{m.inspect}")}

Note 1. kermit.methods will return all methods inherited or not.
Note 2. remove method is a class method, so it's evaluated in the
context of the class object, hence Muppet.instance_eval
Note 3: you could alternatively pass symbols for the method names

kermit.class.instance_methods(false).each{|m|
Muppet.instance_eval("remove_method :#{m}")}



-- 
Rick DeNatale

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