isinstance() considered harmful

[Jason Orendorff]

Kragen Sitaker wrote:
> Generally, though, even the try: except AttributeError: code is a
> mistake.  There are exceptions.

Yes, I agree with that.

> >  (b) it left room for writing much faster Python code in a
> >      future version, the way explicit interfaces do; and
> 
> Can you elaborate?  Are you talking about vtables?

Yes.

> Well, there are three proven ways to get fast compiled code by having
> the compiler know what types it's compiling code for: [...]
>
> There's also a fourth way, Stalin-style type inference,

I didn't know there was a programming language named after Stalin.
How does it differ from Java?

I'll talk more about interfaces later.  My question is,
are explicit interfaces considered harmful too?

## Jason Orendorff    http://www.jorendorff.com/