[sc34wg3] TMQL Requirements, collation

Patrick Durusau patrick at durusau.net
Wed Sep 2 12:45:11 EDT 2009


A little harder question this time on the requirements:

In the TMQL Requirements document, 3.1 Relationship to other standards, 
#3 says:

> Any ordering of strings shall be based on externally-defined 
> specifications for internationalized string collation. Candidates are 
> the Unicode Collation Algorithm [UTR10] 
> <http://www.itscj.ipsj.or.jp/sc34/open/0448.htm#UTR10>, and ISO 14651 
> [ISO14651] <http://www.itscj.ipsj.or.jp/sc34/open/0448.htm#ISO14651>.
OK, but isn't collation order going to be necessary for string 
comparison functions?

That is to say we should require that TMQL define a *method* for 
referencing a collation order and therefore string functions (such as 
comparison) depend upon the collation order specified? (all collation 
being defined outside of TMQL)

I say this because the recent experience in functions for XQuery and 
XPath wound up punting on the issue of collation so far as I can tell. 
All is implementation defined. Although they say an identifier can be 
created for collation orders.

They do reference a "Unicode code point collation" but as far as I can 
tell they only name it and never define it. I have posted a note to the 
W3C about that as an issue.

In the interest of moving forward, my suggestion is that TMQL define a 
reference mechanism (perhaps adopt that of the W3C?) and say which 
functions depend upon collations so specified. (From what I remember 
from character encoding issues and more recent reading, this can be a 
real time/resource sink. As tempting as it is, probably best just to "go 
around" the issue and let others take point on it.)

BTW, ISO 14651, which was at FCD when that reference was written, is now 
an ISO standard. ISO/IEC 14651:2007.

I suggest that anyone interested in these issues obtain a copy of that 
document from your national body. (Now lists for CHF 142,00)

Hope everyone is having a great day!


Patrick Durusau
patrick at durusau.net
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)

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