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Re: The meaning of the "string" datatype?

• From: "G. Ken Holman" <gkholman@C...>
• To: "xml-dev@l..." <xml-dev@l...>
• Date: Wed, 15 Apr 2009 08:04:22 -0400

At 2009-04-15 07:38 -0400, Costello, Roger L. wrote:
>Hi Folks,
>
>Consider this XML Schema declaration:
>
>    <element name="Author" type="string" />
>
>I want to reconfirm my understanding of what the declaration means:
>
>In an instance document:
>
>     <Author>__________</Author>
>                 ^
>                 |
>                 |
>The content of <Author> can be characters from any language

Not sure why you are citing languages here ... the content is defined 
as from ranges of Unicode characters.

>Furthermore, the length of the content of <Author> is unconstrained: 
>it would be perfectly valid to place a billion characters between 
>the start tag and end tag.

Sure ... your schema fragment hasn't added any length 
constraints.  XML doesn't say anything about lengths, but schema 
languages are welcome to do so (not many do).

>[1] The allowable characters for the string datatype is any 
>character in these hex ranges:
>
>Char    ::=    #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | 
>[#x10000-#x10FFFF]

Only if you are talking XML 1.0.

If you use XML 1.1 you get more:

[2]    Char    ::=    [#x1-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]

... noting that according to production [2a] some of those characters 
cannot be naked characters and must be expressed using an escape mechanism.

I hope this helps.

. . . . . . . . Ken

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• References:
  • The meaning of the "string" datatype?
    • From: "Costello, Roger L." <costello@m...>