What is Expressiveness in a Computer Language
Anton van Straaten
anton at appsolutions.com
Sat Jun 24 18:54:36 CEST 2006
Chris Smith wrote:
> Dr.Ruud <rvtol+news at isolution.nl> wrote:
>>The 'dynamic type' is just another type.
> That's essentially equivalent to giving up. I doubt many people would
> be happy with the conclusion that dynamically typed languages are typed,
> but have only one type which is appropriate for all possible operations.
I'm not sure if this is what you're getting at, but what you've written
is precisely the position that type theorists take. Having "only one
type which is appropriate for all possible operations" is exactly what
the term "untyped" implies.
> That type system would not be implemented, since it's trivial and
> behaves identically to the lack of a type system, and then we're back
> where we started.
This is why I've suggested that "untyped" can be a misleading term, when
applied to dynamically-typed languages.
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