From: nobu.nokada@...
Date: 2004-07-06T18:55:37+09:00
Subject: Re: Initialize returning nil if error condition - how

Hi,

At Tue, 6 Jul 2004 16:37:49 +0900,
Graham Nicholls wrote in [ruby-talk:105342]:
> I've got "The Ruby Way" & "Programming Ruby", but can't find out how to have
> an initializer return nil if theres a problem - something like this:

Default Class#new always returns created instance unless any
exceptions occurred.  What you want isn't impossible by your
own "new" class method, but raising an exception in
"initialize" is much better.

  class CoverFile
    def initialize(fname)
    end
    def self.new(*args, &block)
      if obj = allocate()
        obj.__send__(*args, &block)
      end
      obj
    end
  end

-- 
Nobu Nakada