Re: Dylan's type system

[moon (David A. Moon)]

> Date: Wed, 30 Sep 1992 18:46:49 +0100
> From: Jonathan Bachrach <Jonathan.Bachrach@ircam.fr>
> ....

This was an interesting message, but right now I just want to comment on one 
part of it:

> Finally, now that Dylan has types, there are no rules for
> type-checking.  For instance, what types of objects can someone
> legally assign to another object of a given type.

There is no operation in Dylan that assigns an object to another object.  
Dylan does not have any operation like = in C++.

I think you'll find that all of what you would call Dylan's type checking 
rules are expressed in terms of method applicability.  That simplification is 
quite intentional on the part of the language designers, I believe.