From: Stefano Crocco <stefano.crocco@...>
Date: 2006-11-29T18:07:05+09:00
Subject: Re: open classes, constructors and blocks

Alle 09:49, mercoled� 29 novembre 2006, Andrea Fazzi ha scritto:
> �alias foo_initialize initialize
> �def initialize
> � �foo_initialize
> � �@var = "Foo's instance var"
> �end
> end
> 
> Foo.new { |foo| puts foo.var }
> 
> The problem is that the block passed to the new constructor is never 
> called! Why?

When you call foo_initialize from initialize, you're calling a completely 
unrelated method, so the block won't be automatically passed to it (this is 
different from when you use super; in that class the block is passed 
automatically). In your case, you must pass the block in two ways: the first 
is to create a new block which simply calls yield:

  def initialize
   @var="Foo's instance var"
   foo_initialize{yield self}
  end

(by the way, you need to assign @var before calling foo_initialize if you want 
its value to be displayed, otherwise you'll get nil).
The other way is to pass the block as a variable to initialize, using the & 
syntax:

  def initialize &block
   @var="Foo's instance var"
   foo_initialize &block
  end

I hope this helps

Stefano