From: Tom Sawyer <transami@...>
Date: 2002-07-26T01:33:53+09:00
Subject: Re: A Code Challenge

THANKS YOU ALL FOR PARTICIPATING! SOME COOL CODE!

paul. i think i'll give you the prize $ cha-ching ;-) your solution is
the overall best i think. rich's and the lucky stiff's were definite
feats and took some extra things into consideration which was nice:
arity error checking for instance. and ned's was amazingly short and
sweet --good for toplevel execution. but yours is small and versitle and
is much like what i finally worked out myself, only i kept it external
from the object:

    m = o.method(:x)   # get the object method
    mod = Module.new   # make a module with redefined method
    mod.module_eval { 
      define_method(:x) { |*args|
        m.call(*args)
        p.call(*args)
      }
    }
    o.extend mod       # extend object

i wonder how send vs. module_eval compare?

thanks everyone. hope it was a fun and educational.

~transami

On Thu, 2002-07-25 at 08:25, Paul Brannan wrote:
> I will first answer your question with a question:
> 
>   *** WHY!?! ***
> 
> But here's a solution, just for fun (based off the same idea as
> [ruby-talk:29122]):
> 
>   class Object
>     def append_to_method(method_name, p)
>       m = method(:x)
>       mod = Module.new
>       mod.send(:define_method, :x) do |*args|
>         m.call(*args)
>         p.call(*args)
>       end
>       extend(mod)
>     end
>   end
> 
>   class O
>     def x(a)
>       puts "do something with #{a}"
>     end
>   end
> 
>   o = O.new
>   p = Proc.new { |a| puts "do something else with #{a}" }
>   o.append_to_method(:x, p)
>   o.x("foo")
> 
> The only disadvantage I can think of is that if x takes a block, you can
> now no longer pass it a block.  I figure this probably isn't a problem
> anyway since you are appending a proc to it, which cannot take a block.
> 
> Paul
> 
> 
-- 
~transami