RE: [xml-dev] XML Max Character Value

From
Michael Kay <>
To
'Alan Gutierrez' <>, 'Derek Denny-Brown' <>
Date
2005-08-14T21:24:38Z
Thread
RE: [xml-dev] XML Max Character Value
In XSLT 2.0, the collation used by xsl:key is not necessarily Unicode
codepoint order. To build an index, you need to store the key value as a
sequence of collation units, not as a sequence of Java chars or Unicode
codepoints. So I suspect that what you really want is the highest collation
unit in the particular collation used for the key in question.

(Actually, xsl:key only supports equality semantics, not ordering semantics.
But I can see that you probably want to implement indexes that also support
ordering semantics. It's likely that these too would need to be
collation-sensitive.)  

Michael Kay
http://www.saxonica.com/


> -----Original Message-----
> From: Alan Gutierrez [mailto:] 
> Sent: 13 August 2005 12:06
> To: Derek Denny-Brown
> Cc: 
> Subject: Re: [xml-dev] XML Max Character Value
> 
> * Derek Denny-Brown <> [2005-08-13 01:29]:
> 
> > In java, 0xFFFE or 0xFFFF should work.  They aren't strictly the max
> > Unicode character for XML, but since Java represents 
> Unicode as utf-16
> > but doesn't really provide much support for surrogate pairs (last I
> > checked), those should work.  Hm.. Eclipse tells me that there is
> > Character.MAX_VALUE.  Use at your own risk.
>     
>     I am using it to design the algorithm.  Concerned about what to
>     do if Unicode requires multiple characters for a single
>     character. It's perplexing.
> 
> > Reading up on Unicode is also recommended though... 
> internationalization
> > is far, far more complicated than you ever imagined.  I 
> know people who
> > get the shakes if you just mention "Turkish 'I'" in their presence.
> > (mild exaggeration...)
> 
>     I have no illusions about the complexity. I'd simply hoped that
>     they would have made a hard and fast rule about min and 
> max values.
> 
>     Thank you.
> 
> --
> Alan Gutierrez - 
>     - http://engrm.com/blogometer/index.html
>     - http://engrm.com/blogometer/rss.2.0.xml
> 
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