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Re: Two quick questions regarding restriction in XML Schema

• To: Jeff Greif <jgreif@a...>
• Subject: Re: Two quick questions regarding restriction in XML Schema
• From: Murali Mani <mani@C...>
• Date: Wed, 22 May 2002 19:37:58 -0700 (PDT)
• Cc: <xml-dev@l...>
• In-reply-to: <051101c201f2$8744c660$6400a8c0@JMG>

XML Schema does exactly what typical programming languages provide,
probably slightly more using block etc.

However, the question is do you really care what type names the user
provides...

your example is not very clear -- you allow president and VPs to form a
bowling team based on your subtype relationships.

Probably the question you wanted to ask is as follows:
Suppose you have a professor and student defined by
professor -> (name, university?)
student -> (name, university)

now, the implicit subtyping will give student is a subtype of professor...
But this seems like it should not happen...

The problem with XML is given a document with anode having children
name and university, if we validate it againt professor and against
student, they both return true, So who determines what the type should
be?? These are things which should be thought about..

anyways.. cheers - murali.

On Wed, 22 May 2002, Jeff Greif wrote:

> There is some danger in using 'accidental' subtype relationships that
> arise from similar but unrelated hedge types.
>
> We could have:
>    president isa manager isa employee isa person
>   vice-president isa manager isa employee isa person
>
> and hedge types:
> company-bowling-team -> (employee+)
> 5-year-plan-strategists -> (president, vice-president*)
>
> Yes, the president and vice-presidents could form a bowling team,
> but it's unlikely that the author of these types had that in mind.
>
> Jeff
>
>
>
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• References:
  • Re: Two quick questions regarding restriction in XML Schema
    • From: "Jeff Greif" <jgreif@a...>

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