Classes make me mad

[Guy Steele - Sun Microsystems Labs <address@hidden>]

Despite the fact that many folks I respect swear by classes, I've yet to
feel comfortable with them in a language.  Since LL2, I've been trying
to figure out what my resistance is based on.

Let me say that I think that classes are beautiful and powerful and all
those good things.  Let's not quibble about that.

Defining a class is often an act of defining a language construct and
implementing it.  Reasonably or not, I hold language constructs to a
higher standard than, say, a mere function definition.  Specifically,
* I expect classes to be implemented perfectly.  I must
trust my compiler.
* I expect classes to be documented precisely.  I must trust
the documentation.

I know precious few programmers who document well at all, much less to
the level I expect in a language definition, and I know precious few
programmers who implement and test their own code to the level expected
in a compiler.  Therefore, I'd expect more problems from classes than
benefits.

Are these technical reasons?  No.  But they are practical reasons, and
ultimately I program practically.  Classes may be great for individuals
and small groups, but I just don't believe that they scale for these
non-technical reasons.

Guy