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From: lsr@apple.UUCP (Larry Rosenstein)
Newsgroups: comp.sys.mac
Subject: Re: Information, please (MPW and Object Pascal)
Message-ID: <395@apple.UUCP>
Date: Wed, 21-Jan-87 15:37:15 EST
Article-I.D.: apple.395
Posted: Wed Jan 21 15:37:15 1987
Date-Received: Thu, 22-Jan-87 01:55:28 EST
References: <8017@tekecs.TEK.COM> <976@gould9.UUCP> <5306@clyde.ATT.COM> <320@escher.tc.fluke.COM>
Reply-To: lsr@apple.UUCP (Larry Rosenstein)
Organization: Advanced Technology Group, Apple Computer
Lines: 51

In article <320@escher.tc.fluke.COM> mce@tc.fluke.COM (Brian McElhinney) writes:
>Object Pascal and MacApp are sold separately from MPW, so the total
>cost is more like $300-400 (I didn't pay attention to the release

The current APDA prices are MPW: $100, MPW Pascal: $75, MPW C: $75, MacApp:
$50.  If you are doing development using MacApp, this makes the total price
$225.  These prices are going to be raised as of March 1, I believe.  (I
haven't gotten the latest APDA Log yet, so I don't know the exact new
prices.)  There is a free upgrade to the final version for people who
bought the beta releases.

>I have some problems with the lack other object-oriented extensions to
>Object Pascal.  The official line from Apple is that it confuses the
>poor programmer.  

The kinds of extensions that Object Pascal doesn't have are class objects &
methods, and multiple inheritance.  We specifically left these out of
Object Pascal in order to simplify the language.  There were 2 main reasons
for this.

First, if MacApp was written to use these "advanced" features, then
programmers learning MacApp would have to learn the additional language
features as well.  Class objects, metaclasses, and multiple inheritance are
known to be much more difficult to learn than the basic object-oriented
concepts.

The audience for MacApp and Object Pascal are experienced programmers, who
do not necessarily have any object-oriented background.  In addition, people
choose to use MacApp because it speeds up program development.  The more
learning time we add before people can use MacApp, the less attractive it
becomes. 

Second, it takes extra development time to add these features to the
language.  This is especially a problem for 3rd party language developers.
The more features we add to Object Pascal, the harder it is for them to
enhance their languages to work with MacApp.

In designing Object Pascal and MacApp we made some compromises in be the
"pure" object-oriented programming style.  Our primary goal was to build a
tool that Macintosh developers would find useful; learning time,
performance, and code size, therefore, were important considerations.

-- 
Larry Rosenstein

Object Specialist
Apple Computer

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