[ruby-talk:00630] Re: Next misbehavior (sorry :-)

Hi,

In message "[ruby-talk:00626] Next misbehavior (sorry :-)"
    on 99/08/11, [e-mail] <[e-mail]> writes:

>Only `Object' and `Struct' instances seems to call `initialize'.

Matz said that initialize is a "getleman's agreement". Because, in
some cases, it is too late to call initialize after the construction
of object. For example, an array must be allocate memory when
construction. Many predefined classes have such property. (sorry, I
know my explain is not enough but I can't do well). 

So, you can choose

  (1) define MyString without ``< File''

	require "delegate"

	class MyString<DelegateClass(String)
	  def initialize(*args)
	    print "Enter `initialize' with args=`#{args}'\n"
	    super (args[0] || "")
	    print "After parent initialization\n"
	  end

	  def show
	    print to_s, "\n"
	  end
	end

  (2) redefine `MyString.new', not `MyString#nitialize. 

	class MyString<String
	  class << self
	    def new(*args)
	      res = super(args[0] || "")
	      res.instance_eval{ initialize(*args) }
	      res
	    end
	  end
	  
	  def initialize(*args)
	    print "Enter `initialize' with args=`#{args}'\n"
	    print "After parent initialization\n"
	  end

	  def show
	    print to_s, "\n"
	  end
	end

>Furthermore some classes have no `new' method. would it make sense to
>add one (for alibi purposes)?

It was requiested by me and some persons. Because we can't imagine a
`new' numeric.

-- gotoken