Re: Strong Typing, Dynamic Languages, What to do?

[Michael Vanier <mvanier@cs.caltech.edu>]

Still off-topic, sorry...

> From: Eli Barzilay <eli@barzilay.org>
> Date: Wed, 20 Mar 2002 18:38:33 -0500
> 
> I think that the best would be to get the advantages of both, which is
> why I like the fact that the PLT people respect types (instead of
> blind flamewars).  (I had infinite discussions with the local static
> representative and I think that the static world would benefit too
> from being a bit more dynamic.)  I think would be nice if ML would
> somehow substitute C as the foundation things are built upon.
> 

Amen to the last comment, but it's not going to happen any time soon ;-)

As for the first comment, I've been interested in hybrid approaches
(usually called "optional static typing") for some time.  I guess the
canonical example is Dylan, though Common Lisp also qualifies to some
extent (depending on the compiler).  Such systems don't seem to have had as
much impact as you'd expect, for reasons I don't entirely understand (never
having worked with them).  It's possible that having some dynamic types
"pollutes" the staticness of the static types so that essentially the whole
program ends up being dynamically typed anyway.  Also, such languages don't
usually support the many elegant ML-style constructs which have been
developed to make statically-typed systems more flexible (algebraic data
types, pattern matching, parametric polymorphism) and thus end up using
dynamic types where static types could suffice (does Dylan support
containers parameterized on types?).

Mike