From: Christoph <chr_news@...>
Date: 2002-09-07T11:20:51+09:00
Subject: Re: Ruby aesthetics


"Reimer Behrends" wrote in
....
> The problem with nested definitions is that you have identified
> an abstraction (the nested defs) that cannot possibly be reused
> or varied, since they are hidden within that function.

Yes, our neurons seem to work on the wave-length ... to make my
point this was my solution to this problem

sqrt = Class.new do
  def self.[](x)
    new(x).iter(1.0,2.0)
  end
  private_class_method :new
  def initialize(x)
    @x = x
  end
  def good_enough(g1,g2)
     ((g1 - g2).abs / g2) < .001
  end
  def improve(guess)
    (guess +  @x / guess) /2.0
  end
  def iter(g1,g2)
    good_enough(g1,g2) ?  g2 : iter(g2, improve(g2))
  end
end

p sqrt[4.1] # ...

Rather then writing a couple of interconnected methods
or procs  I find it often preferable to write a (or several)
specialized  ``method'' class(es) or  module(s).


/Christoph