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From: RAYBRO%UTRC@utrcgw.utc.COM ("William R Brohinsky", ay)
Newsgroups: comp.lang.forth
Subject: RE: Incapsulation and visibility in Forth
Message-ID: <8908031600.AA27902@jade.berkeley.edu>
Date: 2 Aug 89 22:45:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Forth Interest Group International List <FIGI-L%SCFVM.bitnet@jade.berkeley.edu>
Organization: The Internet
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Mikael Patel:
I must admit that I don't have a good grasp on "incapsulation", as you
are using it. I think a definition or reference to some available work
would be helpful.

Most forths have some "behead" mechanism which leaves "orphan" code with
only those words that call it knowing where to find it. After the beheading,
the user is not able to use the word directly unless he can find the PFA and
incorporate it directly (push it on the stack as a literal and EXECUTE it,
usually speaking). I dislike this very much. In my experience, if you can
use any forth words as forth words, you are a "programmer" as well as a
user, or at least have the ability to act as such. I really dislike ASYST,
PolyFORTH(tm), and a few other implementations for doing just this: there
is no decompile, and may be no word listing facility, so that the "proprietary"
portions of the code stay that way.  The carrot for me as programmer is the
ability to see how EMIT was done when I need a new EMIT-type word, allowing
MYEMIT to function similarly to how the person(s) who implemented my forth
did it.

For those of you who wrote your own forths (which I will, Leo, in my copious
spare time, some day...), why would you WANT to have a mechanism to hide words
from yourselves?  I are times when I see things like this (or like C) that I
believe in my heart-of-heart that I am an inferior outsider. Can the rest of
you really remember everything you ever wrote without ever having to decompile?
Am I the only one to ride on the coattails of my putative implementator?
Or to forget what STLSRGAT was supposed to do? When I don't burn my bridges
behind me, I shorten the time a bad memory imposes on me when I must back-
track.

Maybe when I see the reason for the importance of incapsulation and visibility
as programming language parameters (if indeed, programming languages can be
so parameterized), I will realize that I am also the only one of us with his
thigh in his mouth...
-raybro