From: Brian Candler <B.Candler@...>
Date: 2007-03-16T15:25:46+09:00
Subject: Re: Anyone playing with higher order messaging in ruby?

On Thu, Mar 15, 2007 at 04:04:01AM +0900, Christoffer Lern? wrote:
> For example, something that I often want to do is:
> 
> array.each { |entry| entry.do_something(1, "a") }

If do_something doesn't take any arguments then there's the hack which
allows

   array.each(&:do_something)

See http://pragdave.pragprog.com/pragdave/2005/11/symbolto_proc.html

> If you know you're doing things like this a lot, there is an obvious  
> shortcut:
> 
> class Array
> 
>   class Forwarder
>     def initialize(array)
>       @array = array
>     end
>     def method_missing(symbol, *args)
>       @array.each { |entry| entry.__send__(symbol, *args) }
>     end
>   end
> 
>   def each_do
>     Forwarder.new(self)
>   end
> 
> end
> 
> Now you can do:
> 
> array.each_do.do_something(1, "a")

or just:

module Enumberable
  def each_do(meth, *args, &blk)
    each { |item| item.send(meth, *args, &blk) }
  end
end

array.each_do(:do_something, 1, "a")

which has the advantage that do_something can take a block too, if you wish.

B.