From: Joel VanderWerf <vjoel@...>
Date: 2003-05-12T06:14:03+09:00
Subject: Re: [RCR?] Enumerable#each with arguments

ts wrote:
>>>>>>"J" == Joel VanderWerf <vjoel@PATH.Berkeley.EDU> writes:
> 
> 
> J> I don't understand. Neither of your #each methods takes arguments.
> 
>  You have found the fix :-)
> 
> J> In the case of instances of REXML::Elements#each, an optional XPath string.
> 
>  and if someone want to call it with 2, 3, ... arguments ?
> 
>  For me, your problem seems specific to a class (REXML::Elements)

There's another example, and it's in Ruby itself: ObjectSpace. It's 
always puzzled me that ObjectSpace doesn't inherit from Enumerable, so 
you can't collect, select, etc. So why not do this:

   class << ObjectSpace
     include Enumerable
     alias each each_object
   end

   module Enumerable
     def collect(*args, &block)
       rslt = []
       if block
         each(*args) {|x| rslt << yield(x)}
       else
         each(*args) {|x| rslt << x}
       end
       rslt
     end
   end

   p ObjectSpace.collect(Class) {|c|c.name}.sort[0..9]

The last line is a little bit easier than what works now:

   tmp = []
   ObjectSpace.each_object(Class) {|c| tmp << c.name}
   p tmp.sort[0..9]

Which one is more ruby-like?