From: Frank Mitchell <frankm@...>
Date: 2000-06-17T13:02:29-07:00
Subject: [ruby-talk:03487] Re: Static Typing( Was: Waffling between Python and Ruby)


Patrick Schoenbach wrote in message ...
>On Sat, 17 Jun 2000 09:32:08 GMT,
>Thaddeus L. Olczyk <olczyk@interaccess.com> wrote:
>
>>On Thu, 15 Jun 2000 22:11:34 -0400, Andrew Hunt <andy@Toolshed.Com>
>>wrote:
>>>I disagree strongly.  While Meyer is an advocate of static typing, I
>>>see no reason that DBC cannot be effective in a dynamically typed
>>>environment -- in fact, it seems to me that DBC could be even *more*
>>>useful in a dynamic environment than in a static one.
>
>I agree with Andy here. IMHO DBC and typing are two different things. We
>Eiffelists believe that static typing is better suited to create robust
>and correct systems. This is heavily argued thought, and we should not
>start another "static vs dynamic typing" war.


Agreed.  Dynamic typing is very useful for rapid development, and for
high-level "glue" code the rigor of strong typing hinders as much as (or
more than) helps.

>But DBC is not directly related to the typing issue. Even in Eiffel,
>assertion checking is done completely at *run time*. So, I see no
>problems either to implement DBC in a dynamic environment.


I think it's more closely related than it seems at first blush.  See my
previous post.

Granted, your contracts can include a union of types, or "types" defined by
a set of methods and contracts instead of by name ... but to exploit the
power of DBC you need some sort of type system and type checking.


Frank