From: Matt Maycock <ummaycoc@...>
Date: 2004-10-20T23:04:03+09:00
Subject: hash <<

So, unless you count merge! and update, there doesn't seem to be a way
to shove stuff into a hash and get the resulting updated hash back. 
Now, I know merge and update make it real easy:

  h = {}
  h.update(:a => :b).update(:c => :d).update(:e => :f)

but this some how feels unnatural to me.  maybe the following is
better for me and others?

---code---
require 'ext/singleton_class'

class Hash
  def <<(k)
    if @shift_value.nil? then
      @shift_value = Object.new.singleton_def(:key) {k}
    else
      key, @shift_value = @shift_value.key, nil
      self[key] = k
    end
    self
  end
end
---end code---

---usage---
h = {}
h << :language << :ruby << :creator << :matz << :users << :"comp.lang.ruby"
p h
---result---
{:language=>:ruby, :creator=>:matz, :users=>:"comp.lang.ruby"}
-------------

Just a question of flavour, really.

-- 
There's no word in the English language for what you do to a dead
thing to make it stop chasing you.