From: David King Landrith <dave@...>
Date: 2003-03-25T05:21:05+09:00
Subject: Re: Writing a new method in C for a subclass


On Monday, March 24, 2003, at 11:30 AM, Brian Candler wrote:

> On Tue, Mar 25, 2003 at 01:07:40AM +0900, David Landrith wrote:
>> Unless all inheritance is handled by rb_define_class
>
> Yes you should be able to subclass Array directly. Try:
>
>     rb_cMyArray = rb_define_class("MyArray", rb_cArray);
>
> which I understand to be the same as
>
>     MyArray = Class.new(Array)
> or
>     class MyArray < Array
>     end

This much I understand.   This is a complicated topic, and it looks 
like what I wrote before was rather convoluted.  If anyone is able to 
restate what I'm trying to ask in a more straightforward manner, I'd 
appreciate it.

I am wondering if there is anything special that I must do to create a 
method that instantiates a new MyArray object in c.  All of the 
examples of "new" methods (meaning a methods that are declared using 
the form rb_define_singleton_method(myClass, "new", myClass_new, argc) 
simply extend rb_cObj.

I know that if I extend the Array, then I will create a class whose 
objects will have the same set of values as Array.  It seems that in 
order to define a class from the ground up (meaning including the "new" 
method), you need to create a struct, wrap it, and return the VALUE 
pointing to the wrap.  I can do this easily enough, but if I am 
extending a class, do I create a struct that points to the super class? 
  or do I create a struct that contains all of the values in the 
superclass?  or am I on entirely the wrong track?

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David King Landrith
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