Re: the forward method [dynamic vs. static typing]

[address@hidden (Jeremy H. Brown)]

Tom Lord <lord@emf.net> writes:
> But, anyway, it wasn't _conciseness_ I attributed to DT but a unique
> (in some sense) minimalism of details -- avoidence of having to
> provide redundant information.  How much do you have to say about a
> program in order to execute it correctly?  ST languages require you to
> say more than that.

But how many undetectable ways are there to say a program such that it
executes incorrectly?  DT languages give you more rope.

More generally, redundancy isn't inherently bad.  (I don't mean to say
that you're claiming it is, but I want to explicitly make the point.)
The redundancy of ST, much like the redunancy of computing parity,
buys you early detection of certain classes of errors.

The lowest-redundancy, highest-entropy programs look like line-noise,
and a single bit error can render one incorrect without any hope of
being detected.  (I'll let someone else take the obligatory whack at
Perl now.) 

*Any* correctness assertions you can make about a program, whether
related to type or not, are redundant --- but can be a real lifesaver
when you're bughunting.  (And of course, a Sufficiently Clever
Compiler (TM) can take advantage of all sorts of correctness
assertions, types and otherwise.)

Jeremy
(another fan of DT languages with optional type assertions)