> In the case of Ocaml, we might say that when many messages
> of the form: "This expression has type SquarePeg but is here
> used with type RoundHole" have been fixed by sandpapering
> off the edges of those pegs .. the program is the residual sawdust
> that remains on the floor after thousands of curses.
>   
^_^

You might really be interested in toying around with interactive 
systems. I would probably advise Adga2 ( 
http://appserv.cs.chalmers.se/users/ulfn/wiki/agda.php ) or Epigram 1 ( 
http://www.e-pig.org/ ).

Interactive programming tends to save quite a few weird error messages. 
The type systems of these are of the sort we were discussing on this thread.


Arnaud Spiwack