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From: dwp@willett.pgh.pa.us (Doug Philips)
Newsgroups: comp.lang.forth
Subject: Re: ... and zen there were objects.
Message-ID: <1680.UUL1.3#5129@willett.pgh.pa.us>
Date: 7 Sep 90 00:51:17 GMT
References: <11485@medusa.cs.purdue.edu>
Organization: String, Scotch tape, and Paperclips.  (in Pgh, PA)
Lines: 56

In <11485@medusa.cs.purdue.edu>, bouma@cs.purdue.EDU (William J. Bouma) writes:

>     Your whole argument is based that the objects are unknown, computed on
>     the fly. On top of that, you aren't quite sure what other arguments are
>     to be included with the messages you are going to send! How often is this
>     going to happen? To convice me, you will need to give something more
>     specific than just the vague generalities so far! You seem convinced this
>     sort of thing will be happening all the time.

Consider the ubiquitous list of graphical objects.  The "list" is itself
an object.  Consider the following example

	' SomeWord Map-Over List-Specifier SEND

where:	 SomeWord is a word which pushes a message (arguments first, then
	     message "key".
	 Map-Over is the message which takes one argument, an
	     execution-token.  Map-Over asks a list object to iterate over
	     its list and for each object, in turn:
		     first execute Map-Over's argument which is supposed to
			 cause a message and its arguments to be put onto the
			 stack.
		     push the object under consideration on the stack.
		     execute SEND.
	List-Specifier is arbitrary Forth code that leaves a list object
	    on the top of the stack.

In case that explanation isn't clear:  Send the message generated by
a call to SomeWord to each object in the list specified by the arbitrary
Forth code "List-Specifier".  Map-Over itself could be a constant, or
a string, or any other arbitrary Forth code.  How the message id is
generated is not important to this example.

>      our current discussion? I thought we had dealt with this issue 5 or 6
>      messages ago. You mistakenly think I have changed my position.

You changed your style in your last set of examples.  At first you had
active message names, but your latest round of examples showed quoted
message names without the quoting mechanism.  Perhaps that was an
unintentional change in style.


It has become abundantly clear that I am unable to get through to you.
There is no arbiter for the definition of OOP.  I hold that OOP, to be
meaningful, involves a shift in the way one looks at programming.  It is
not "merely" indirect function calling.  I cannot prove that any more than
I can prove that short word definitions are more the style and philosophy
of Forth than long word definitions are.

-Doug

-Doug

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