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From: dtt@unirot.UUCP (David Temkin)
Newsgroups: net.micro.mac
Subject: Re: What are Object Pascal and MacApp?
Message-ID: <945@unirot.UUCP>
Date: Tue, 5-Aug-86 13:13:11 EDT
Article-I.D.: unirot.945
Posted: Tue Aug  5 13:13:11 1986
Date-Received: Tue, 5-Aug-86 22:51:51 EDT
Reply-To: dtt@unirot.UUCP (David Temkin)
Organization: Public Access Un*x, Piscataway NJ (The Soup Kitchen)
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[sorry if this message is preceeded or followed by an old message of
mine; the posting software here has problems and sometimes does that]

Eric Ivancich @ University of Utah CS Dept. writes:

> I just received an announcement from TML Systems for their (his) v2.0
> upgrade.  The enhancements Mr. Leonard lists include:
>     o Object Pascal as defined by Apple Computer (what exactly is this?)

Object Pascal is an extension of Pascal jointly designed by Niklaus Wirth
(the original designer of Pascal and Modula 2) and prgrammers at Apple.
The new language supports a new type, the "object", which is like a
record except that it may contain procedures and functions, as well
as data (integers, str255s, arrays, records) and other objects. Each
object is defined to have a "parent" object -- that is, another
object whose procedures and functions (collectively known as
"methods") are considered to be "inherited" by the object. There is
then a hierarchy of objects, where each object is described by its
differences from those "above" it. Objects can redefine inherited
variables and methods as well as define new ones.

MacApp is a library of objects meant to be used from Object Pascal
when writing a Macintosh application. It eases the implementation of
the Macintosh User Interface by providing the "generic" features of a
Mac application and letting you build on these. For example, DAs,
window updating, printing, and event processing can be handled in
your application with no coding needed. You build on top of this
base, defining new objects for the application-specific code.
You can also redefine provided routines to alter the standard
objects' behavior.

If this is all very confusing to you, you're not alone.  I don't
quite understand all of it, and what I do understand isn't exactly
clear in my mind.  I just started reading a book called "Object
Oriented Programming for the Macintosh" (Hayden Books) which
concentrates on Object Pascal and MacApp.  From what I've read, it
seems that this stuff is really useful, and the author claims that
this will be the way to go for Mac development, cutting development
and debugging time substantially.  It seems that Object Pascal will
be the standard Pascal in Apple's Macintosh development system (it's
fully upward compatible with Lisa Pascal as presented in Inside Mac).
The problem with using MacApp/Object Pascal is that involves working
out a new strategy for problem solving on the computer. The old
way of looking at a project (as a hierarchy of routines) differs
radically from the programming model required by object-oriented programming.

Hopefully, someone who is beta-testing this stuff can post a message
regarding its usefulness so we can all get past the hype and
buzzwords surrounding object-oriented programming.