Re: another take on hackers and painters!!

[address@hidden]

In a message dated 5/20/2003 3:02:19 PM Central Daylight Time, costanza@web.de writes:

> >People who criticize static typing should annotate their offering with
> >an indication of how much ML they have written.  That would make them
> >far more credible.
>
> There are some deep problems involved in this statement.
>
> + If personal experience is the right measure for evaluating the 
> usefulness of language features we don't have any ground to discuss 
> these things. Your experience might be totally different from mine so 
> why bother?


I can't speak for Shriram, but I interpret his comment in a somewhat
different way: if your concept of "static typing" is solely due to programming
in Pascal and Java (or, worse, C and C++) you may be arguing against
(or at least attempting to discuss) a different concept of "static typing".
There is a very real point to actually doing some ML or Haskell programming
to understand _that_ concept of "static typing".

For a number of trivial examples (e.g. the beloved factorial and fibonacci examples ;),
the code looks, and is typed in the same manner as a  C program. These are poor
examples for or against static typing. A certain level of non-trivial experience with 
ML-style (or I would add, Haskell-style) "static typing" does add to one's 
understanding--and credibility.

The really deep problem with your comment is the following: some level
of shared experience is necessary: if you are teacher of calculus, it is
pointless to try to teach a student who has not yet grasped algebra!
The same is true in debating static typing--where static typing is the 
concept as in ML or Haskell.

If someone has written a large scale applications in both Scheme and ML, and 
says "once I got the types right, the program worked--the types were a tool for 
debugging the logic of my application"-- that has a lot of weight. (I guess the 
reverse is to say that "getting the types right in ML was a pain; the PLT Scheme
development environment plus dynamic typing helped me figure out _why_ the 
types [and logic] were wrong. ;) Were someone to report this last to be the 
case, I too would be perfectly happy!

Jim Bender