From: Ryan Leavengood <leavengood@...>
Date: 2006-05-25T03:41:28+09:00
Subject: Re: define_method for a single instance?

On 5/24/06, Jake McArthur <jake.mcarthur@gmail.com> wrote:
> I'm trying to define a method for a specific instance of a class
> rather than for every instance of the class. Basically, something
> like this:
>
> class A
>    def add_wibble_method
>      # don't know what to do here
>    end
> end
>
> foo = A.new
> bar = A.new
> foo.add_wibble_method
> foo.wibble # should work
> # bar.wibble should not work
>
> Any help would be appreciated.

irb(main):001:0> class A
irb(main):002:1>   def add_wibble_method
irb(main):003:2>     class << self
irb(main):004:3>       def wibble
irb(main):005:4>         puts "wibble!"
irb(main):006:4>       end
irb(main):007:3>     end
irb(main):008:2>   end
irb(main):009:1> end
=> nil
irb(main):010:0> foo = A.new
=> #<A:0x2ac53f0>
irb(main):011:0> bar = A.new
=> #<A:0x2ac2ed0>
irb(main):012:0> foo.add_wibble_method
=> nil
irb(main):013:0> foo.wibble
wibble!
=> nil
irb(main):014:0> bar.wibble
NoMethodError: undefined method `wibble' for #<A:0x2ac2ed0>
        from (irb):14