[cap-talk] Selling capabilities programming

[Jonathan S. Shapiro]

On Thu, 2007-07-19 at 10:26 +1000, James A. Donald wrote:
>  >> I agree entirely that a language that does not permit
>  >> code to be written which violates capability
>  >> constraints should not be written using sparse
>  >> capabilities.
> 
> Jonathan S. Shapiro wrote:
>  > James: This is equivalent to stating that a
>  > memory-safe programming language should not use sparse
>  > capabilities.
> 
> No it is not.  The most widely used counter example
> would be visual basic and its sharp successors.

But VB# is a memory-safe language. A .Net object reference is a
capability.

> Further, if one was to constrain Visual Basic so that
> programs written the language were guaranteed to respect
> capability contraints that assembly language could
> violate, it would break all existing software written in
> visual basic

For VB I agree. For VB# it is harder, but there are mechanisms even
there.
-- 
Jonathan S. Shapiro, Ph.D.
Managing Director
The EROS Group, LLC