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From: awd@dbase.UUCP (Alastair Dallas)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Need a review of THINK C 4.0
Summary: MacTutor Oct '89
Message-ID: <296@dbase.UUCP>
Date: 8 Nov 89 18:23:57 GMT
References: <1346@mrsvr.UUCP>
Distribution: na
Organization: Ashton Tate Devlopment Center Glendale, Calif.
Lines: 60

In article <1346@mrsvr.UUCP>, quinnt@turing.uucp (Tom Quinn x4-nnnn) writes:
> Please don't post to this newsgroup!  I'm sure this is an old topic.
> If anyone else would like me to forward to them anything I receive
> contact me via e-mail and and I will send it along.

Ah, but I wanted to post to the newsgroup; you just gave me an excuse.

> I've been away from the net since the early summer, and missed any
> discussion/reviews of Think C version 4.0.  I'm still contemplating
> whether to purchase the upgrade, and would like some input for my
> decision.  If anyone has some old articles around, or if someone could
> take the time to summarize the discusisons that must have been held, I
> would appreciate it if you could mail that information to me.

There hasn't been that much discussion, as far as I'm concerned.  I'm 
very enthusiastic about this product--I rushed an article to MacTutor
(Oct '89) to describe it.  This week, however, is the first chance I've
had to really play with it.  I wanted to post because I discovered a
slight error in my article.

TC is basically Think C 3.0 with a few object-oriented extensions and
more ANSI-compatibility.  These changes are not earth-shaking, really.
What is exciting is the Think Class Library which is built
on top of the compiler changes.  TCL is a MacApp alternative, and 
since the compiler changes were done by Kahl, et. al., the environment
is tight--things are relatively small and fast compared to a brute-force
o-o implementation.  (Obviously, I'm being subjective here.)  TC 4.0
comes with Art Class, a MacPaint-type program demonstrating tear-off
pallettes and all kinds of stuff.  Art Class makes it clear that it
is possible to write commercial-quality applications using TCL.  And
since it comes with full source code, you've got a leg up.

Luckily, Rich Siegel of Think and Gregory Dow himself (author of TCL
and Art Class) are available in this newsgroup.  We've had some 
discussion (scanf() has a known bug--.01 becomes .1; the new multi-finder
doesn't let Art Class update your cursor under some circumstances),
but my impression is that a bunch of us are still climbing the learning
curve.

My bug: In the example in my MacTutor article I override CWindow::Close
in order to make clicking in the close box equivalent to the Quit
command.  This is the only reason I create a subclass of CWindow.
What I discovered after RTFM more closely is that overriding CWindow 
is rarely necessary.  In this case, the standard CWindow::Close calls
its supervisor (in my case, a Director) with CDirector::CloseWind.
Since Directors are abstract classes, you have to override them, anyway,
so you might as well respond to CloseWind with gApplication->Quit().
[I hope I got the names right--I left the manual home.]

I would reccommend Think C 4.0 to my mother (except that she's stuck
on APL).  Apple says you gotta know o-o programming to survive in the
Mac world, and I believe them.  Then it's a choice between MacApp,
which is >$500 if you don't already have MPW, some offbeat development
system (Neon?), or Think C 4.0.  TC is a relatively cheap introduction
to the world of o-o, and you can be sure it will be supported for 
the foreseeable future.

Hope that answers your question.

/alastair/