Re: more closed-world chatter
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 05 May 2007 17:07:36 -0300
Message-ID: <463ce3d8$0$4050$9a566e8b_at_news.aliant.net>
>>On May 5, 8:50 am, Jon Heggland <jon.heggl..._at_idi.ntnu.no> wrote:
>>
>>>>when it comes to the advantage of sub-typing in dealing with
>>>>my question.
>>>
>>>I don't know about "advantage"; I just don't see how you can avoid it.
>>
>>It's easy to avoid: just don't put subtying in the language design.
>>
>>Much of the talk in language design in the last ten years or more
>>has focused on various mechanisms for subtyping, but it's an
>>entirely optional language feature. That's easy to forget when
>>it's all anyone's talking about, but it is possible to just leave it
>>out.
>>It's also possible to leave a static type system out entirely.
Date: Sat, 05 May 2007 17:07:36 -0300
Message-ID: <463ce3d8$0$4050$9a566e8b_at_news.aliant.net>
David Cressey wrote:
> "Marshall" <marshall.spight_at_gmail.com> wrote in message > news:1178391422.291226.290880_at_l77g2000hsb.googlegroups.com... >
>>On May 5, 8:50 am, Jon Heggland <jon.heggl..._at_idi.ntnu.no> wrote:
>>
>>>>when it comes to the advantage of sub-typing in dealing with
>>>>my question.
>>>
>>>I don't know about "advantage"; I just don't see how you can avoid it.
>>
>>It's easy to avoid: just don't put subtying in the language design.
>>
>>Much of the talk in language design in the last ten years or more
>>has focused on various mechanisms for subtyping, but it's an
>>entirely optional language feature. That's easy to forget when
>>it's all anyone's talking about, but it is possible to just leave it
>>out.
>>It's also possible to leave a static type system out entirely.
> > You've lost me here. As Bob pointed out a few days ago, all types can be > considered subtypes of the universal supertype. Doesn't that mean that all > typing is, in reality, subtyping? > > If so, how can you implement typing without implicitly implementing > subtyping?
By omitting: the universal supertype, the universal subtype, most types in between and the specialization/generalization connections among them all. Received on Sat May 05 2007 - 22:07:36 CEST