What is Expressiveness in a Computer Language

[David Hopwood]

Pascal Costanza wrote:
> Chris Smith wrote:
> 
>> Knowing that it'll cause a lot of strenuous objection, I'll
>> nevertheless interject my plea not to abuse the word "type" with a
>> phrase like "dynamically typed".  If anyone considers "untyped" to be
>> perjorative, as some people apparently do, then I'll note that another
>> common term is "type-free," which is marketing-approved but doesn't
>> carry the misleading connotations of "dynamically typed."  We are
>> quickly losing any rational meaning whatsoever to the word "type," and
>> that's quite a shame.
> 
> The words "untyped" or "type-free" only make sense in a purely
> statically typed setting. In a dynamically typed setting, they are
> meaningless, in the sense that there are _of course_ types that the
> runtime system respects.
> 
> Types can be represented at runtime via type tags. You could insist on
> using the term "dynamically tagged languages", but this wouldn't change
> a lot. Exactly _because_ it doesn't make sense in a statically typed
> setting, the term "dynamically typed language" is good enough to
> communicate what we are talking about - i.e. not (static) typing.

Oh, but it *does* make sense to talk about dynamic tagging in a statically
typed language.

That's part of what makes the term "dynamically typed" harmful: it implies
a dichotomy between "dynamically typed" and "statically typed" languages,
when in fact dynamic tagging and static typing are (mostly) independent
features.

-- 
David Hopwood <david.nospam.hopwood at blueyonder.co.uk>