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Re: modeling, validating and documenting an xml grammar

• To: xml-dev@l...
• Subject: Re: modeling, validating and documenting an xml grammar
• From: ari@c... (K. Ari Krupnikov)
• Date: 18 Jun 2003 15:09:41 -0700
• In-reply-to: <07dd01c335e0$a6e6b5f0$b6f5d3ce@s...>
• References: <AOEKKCOOGNDOAHCLNEIFKENKDOAA.mike@w...><200306172155.h5HLth113469@d...><07dd01c335e0$a6e6b5f0$b6f5d3ce@s...>
• Sender: ari@l...
• User-agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2

"Jonathan Borden" <jonathan@o...> writes:

> Joe English wrote:
> >
> > What are the real-world use cases of minOccurs and maxOccurs?
> > In my experience, occurrence constraints specifying anything
> > other than zero, one, or many are almost always an indication
> > of a bad design decision somewhere in the system.
> 
> Number of living parents,
> grandparents,
> Number of (one's) kidneys
> Digits on left hand
> Chambers in heart...
> Human chromosomes...

Jonathan, no-one is arguing that one-to-many relationships exist. What
Joe was asking about was if you ever want to specifically quantify the
"many", IOW when "*" or "+" is not precise enough.

Note that your first 5 examples don't even describe interchangeable
things. Presumably, if you want a schema to describe digits on one's
left hand (perhaps to describe scars on them, or fingerprints?), you
don't want to treat them as "hand (digit{0-5})", where the digits are
only differentiated by position. What if a person had 4 digits? Which
one is missing? Similarly, "parents (mother?  father?)" might be a
better representation than "parents (person{0-2})". Parents are not,
as a rule, interchangeable. Neither are heart chambers, but I'm sure
you know more about that than I do.

So back to Joe's question - a real world case where a list of
indistinguishable items is bound by some specific and precise number
other than 0 or 1.

Ari.

• Follow-Ups:
  • Re: modeling, validating and documenting an xml grammar
    • From: Rich Salz <rsalz@d...>
  • Re: modeling, validating and documenting an xml grammar
    • From: John Cowan <cowan@m...>

• References:
  • RE: modeling, validating and documenting an xml grammar
    • From: "Mike Fitzgerald" <mike@w...>
  • Re: modeling, validating and documenting an xml grammar
    • From: Joe English <jenglish@f...>
  • Re: modeling, validating and documenting an xml grammar
    • From: "Jonathan Borden" <jonathan@o...>

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