Re: Constraints and Functional Dependencies
Date: 26 Feb 2007 00:16:40 -0800
Message-ID: <1172477800.339834.167550_at_j27g2000cwj.googlegroups.com>
On Feb 25, 1:57 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
> I suggest a more interesting question to ask is whether one should allow
> implicit type conversions between a singleton set and its contents.
> Another is whether one should allow implicit type conversions of any kind.
Yeah, that's a good question.
I note that "Java Puzzlers" by Bloch and Gafter
http://www.amazon.com/Java-TM-Puzzlers-Pitfalls-Corner/dp/032133678X/
lists a fair number of "puzzlers" which are based on implicit type conversions. It appears that many standard implicit conversions are fraught with peril!
Although the question of singleton-set / contents is not one that I have any experience with, and it strikes me as being at least somewhat qualitatively different from, say, int to long conversion. However I would be inclined to be cautious and want a soundness proof before admitting that feature.
I actually think there might be another approach entirely, one that is found when one turns the "relational closure" dial to 11, as it were.
Marshall Received on Mon Feb 26 2007 - 09:16:40 CET