Re: OO, C++, and something much better!

[Eric Clayberg <clayberg@parcplace.com>]

Norman H. Cohen wrote:
> You seem to be confusing type errors with all other kinds of
> compile-time errors.

I don't think so. I am well aware of what a type error is relative to
the universe of other compile-time errors.

> As you said, "Smalltalk does not lend itself to 'type' errors of that
> nature."  Smalltalk programmers are no less likely than other
> programmers to use an integer variable to index into the wrong array,
> but since Smalltalk does not have the means to express such distinctions
> as type distinctions, I would imagine that most Smalltalk programmers
> would think of this as a "general logic error" rather than as the kind
> of problem that would be caught by compile-time type checks.

Yes, I would definitely consider that a "general logic error" in the
Smalltalk (or C++) context.

> I mentioned the securities industry specifically because Alan Lovejoy
> had brought up the use of Smalltalk in that industry.  This industry has
> perceived that Smalltalk speeds deployment of software, but I suspect
> that few realize that this is accomplished by deferring the detection of
> some errors until after deployment!  

That is not a general property of Smalltalk any more so than of any
other language. Having developed commercial apps in a number of
languages, I have always been amazed at the stability of deployed
Smalltalk apps relative to apps built with other languages. If you say
that apps built with Ada are even more stable, then great. Do you have
any evidence that shows that deployed Ada apps are more stable in
practice than deployed Smalltalk apps? I have never seen anything beyond
supposition and guesses (usually offered up by folks who have never used
Smalltalk).

> The appropriate comparison here is
> not to C++ (an error-prone language whose supposedly strong typing
> system is too weak to catch many of the errors that language fosters),
> but to a safety-oriented language such as Ada.

Are you saying that Ada is incapable of propagating errors to the end
user? All errors are guaranteed to be fixed prior to deployment? That
would be remarkable.

-Eric