From: Bill Kelly <billk@...>
Date: 2004-06-26T06:30:09+09:00
Subject: Re: Is it considered Harmful?


From: "Sean O'Dell" <sean@celsoft.com>
> On Friday 25 June 2004 09:16, Bill Kelly wrote:
> > Supposed an object's class were changed to a different class
> > which was itself (or whose ancestor(s) were) implemented in 'C'
> > code.  Something that expects that once it's initialized it
> > can go ahead and rely on its class invariants pointing to real
> > operating system file handles, window handles, etc.
> 
> No code should "expect" data to be there that isn't.

:)

No ambulator should "expect" the rug to remain steady
under their feet when it might be pulled out from under them.

And yet - we live by many such expectations just to make
it through every day life.  One such expectation, for me,
is that when my constructor or initializer (whether it
be C or C++ or Ruby or Java or Perl or Python or.....)
sets up some private member variables in my object - it
is reasonable for me to expect that they won't be tampered
with by unexpected external tomfoolery.

>  If a C extension wraps a 
> native C struct as a Ruby object with Make_Struct, then when it unwraps it, 
> and gets nothing or a NULL pointer, it shouldn't continue to try and use it.  
> That's sloppy coding.

I'm just getting started writing ruby extensions, so I have a
lot to learn.  


Regards,

Bill