From: Brian Candler <B.Candler@...>
Date: 2004-10-21T05:03:17+09:00
Subject: Re: each with separator

> My inclination would be to start simple:
> 
>   module Enumerable

I suppose, from what I was saying before about it being impolite to pollute
system classes (giving rise to potential name conflicts), that I ought to
separate it out of Enumerable.

  module SuperEnumerable   # choose a unique name here
    def separate_by(separator)
      Separator.new(self,separator)
    end
    class Separator
      include Enumerable
      def initialize(thing,separator)
        @thing = thing
        @separator = separator
      end
      def each
        first = true
        @thing.each do |item|
          yield @separator unless first
          first = false
          yield item   
        end
      end
    end
  end

  a = [1,2,3]
  a.extend SuperEnumerable
  a.separate_by("-").each {|obj| puts obj}
  b = a.separate_by("-").collect {|obj| obj * 2}
  p b

You can always include SuperEnumerable in class Array if you wish, but
you're not required to.

Regards,

Brian.