Re: Mixing OO and DB
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 21 Feb 2008 13:18:12 -0400
Message-ID: <47bdb254$0$4029$9a566e8b_at_news.aliant.net>
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> The "LSP" is merely "marketing speak" concocted by other people.
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> In a way, yes. :-)
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> Specifically : what "principle" is actually in effect here ??
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> That if some type T2 happens to be substitutable for T1 for one
> particular context, that T2 should be a Liskov/Wing subtype of T1 ??
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> Hardly "value-added" (wrt to the Liskov/Wing definitions) is it.
Date: Thu, 21 Feb 2008 13:18:12 -0400
Message-ID: <47bdb254$0$4029$9a566e8b_at_news.aliant.net>
S Perryman wrote:
>> S Perryman wrote:
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>>> There is no "principle" . You appear to have been sucked in like the >>> rest. >>> Re: http://groups.google.com/group/comp.object/msg/a2f843524b98522b
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>> Interesting. Now allegedly, there is no principle in the Liskov >> Substitution Principle.
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> The "LSP" is merely "marketing speak" concocted by other people.
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>> Is that like "there is no there there" ?
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> In a way, yes. :-)
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> Specifically : what "principle" is actually in effect here ??
>
> That if some type T2 happens to be substitutable for T1 for one
> particular context, that T2 should be a Liskov/Wing subtype of T1 ??
>
> Hardly "value-added" (wrt to the Liskov/Wing definitions) is it.
Actually, the principle provides a method to evaluate type systems just as normalization provides a method to evaluate logical designs. Received on Thu Feb 21 2008 - 18:18:12 CET