What is Expressiveness in a Computer Language

[Chris Uppal]

I wrote:

> It would be interesting to see what a language designed specifically to
> support user-defined, pluggable, and perhaps composable, type systems
> would look like.

Since writing that I've come across some thoughts by Gilad Bracha (a Name known
to Java and Smalltalk enthusiasts alike) here:

    http://blogs.sun.com/roller/page/gbracha?entry=a_few_ideas_on_type

and a long, and occasionally interesting, related thread on LtU:

    http://lambda-the-ultimate.org/node/1311

Not much discussion of concrete language design, though.

    -- chris