From: Jenda Krynicky <jenda@...>
Date: 2007-03-17T02:32:48+09:00
Subject: Re: Anyone playing with higher order messaging in ruby?

Christoffer Lernö wrote:
> On Mar 14, 2007, at 20:04 , Christoffer Lern� wrote:
> 
>>     end
>>   end
>> end
>>
>> def trampoline(&block)
>>   raise "Missing block" unless block
>>   Trampolines::Trampoline.new(block)
>> end
> 
> This code adds methods to all enumerables.
> 
> module Enumerable
>    %w(each collect select reject).each do |method|
>      class_eval "def #{method}_do; trampoline { |m, b, *a| #{method}
> { |o| o.__send__(m, *a, &b) } }; end"
>    end
> end

Looks to me that it's easier to extend the Forwarder a bit and implement 
this like this:

class Forwarder
  def initialize(obj, method)
    @obj = obj
    @method = method
  end
  def method_missing(symbol, *args)
    @obj.__send__( @method)  { |entry| entry.__send__(symbol, *args) }
  end
end

module Enumerable
   %w(each collect select reject).each do |method|
     class_eval "def #{method}_do; Forwarder.new(self, :#{method}) end"
   end
end


it's a shame the builtins do not work like this already. And while it's 
possible to overwrite the "collect", "select" and "reject" in 
Enumerable, to overwrite the "each" you'd (AFAIK) have to touch all the 
individual classes.

I should not have to name something I only use once:

 list.each { |x| x.whatever() }

Jenda

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