From: Tom Sawyer <transami@...>
Date: 2002-06-26T20:13:05+09:00
Subject: []<<

here's something i thought was interesting:
(note that the comments are intended)

class Tt

  #attr_accessor :h  # no access to h!

  def initialize
    @h = {}
    @h['test'] = '1..'
  end
  
  def [](xp)        # only want to allow reading
    @h[xp]
  end
  
  #def []=(xp, ap)  # no assignment allowed!
  #  @h[xp] = [ap]
  #end

end

tt = Tt.new
tt['test'] << '..2'         # how come you can do me?
tt['test'] = '1....2'       # if you can't do me!


it seems to me that the main point of accessors and the []= method is to
control accessiblity to a class' instance variables. right? but as this
example shows, there are ways in which "back-doors" exist.

shouldn't there be better control of such thing? i came across this when
i was actually trying to create a []<< method, and realized that i have
never seen such a beast before! shouldn't such a thing exist?

~transami