W3C home > Mailing lists > Public > public-ietf-collation@w3.org > September 2005

Re: comments on draft-newman-i18n-comparator-05.txt

From: Mark Davis <mark.davis@icu-project.org>
Date: Thu, 22 Sep 2005 08:13:18 -0700
Message-ID: <4332CA0E.70506@icu-project.org>
To: Arnt Gulbrandsen <arnt@gulbrandsen.priv.no>
CC: Martin Duerst <duerst@it.aoyama.ac.jp>, Philip Guenther <guenther+collation@sendmail.com>, public-ietf-collation@w3.org

The goal and work so far is good. I'll need to read the document over 
more carefully, but one quick point. The specification should make very 
sure that some formal properties are observed.

 > Since ordering is normally used to sort a list of items, "error" is 
not a useful return value from the ordering function. Strings with 
errors that prevent the sorting algorithm from functioning correctly 
should sort to the end of the list. Thus if the first string is invalid 
while the second string is valid, the result will be "+1". If the second 
string is invalid while the first string is valid, the result will be 
"-1". If both strings are invalid, the result SHOULD match the result 
from the "i;octet" collation.

This does not yet require that the order relation MUST be transitive, 
which is an absolute requirement.

Similarly:

Equality MUST be an equivalence relationship (reflexive, symmetric, and 
transitive).

Ordering MUST establish a total order (that is, < is transitive and 
trichotomous), and must be consistent with the Equality relationship.

Matching MUST be defined such that if there is a match, the substring 
meets the equality criteria. Note: there are some real gotchas in 
matching, see http://www.unicode.org/reports/tr10/#Searching


Also, I haven't looked it over in detail on this point, but with 
reference to attributes, I'd point people to the CLDR specification for 
the kinds of things that are needed.

http://unicode.org/cldr/data/docs/web/tr35.html#%3Ccollation%3E

Mark

Arnt Gulbrandsen wrote:
> 
> Martin Duerst writes:
> 
>> I think this is great! This is the best way to get the draft finally 
>> moving on at greater speed. I happen to know the chair, and I agree 
>> with your description of her abilities.
>>
>> On the other hand, I'm somewhat worried that the we may end up with a 
>> draft that's perfect for IMAP, but doesn't work for other 
>> protocols/formats/languages.
> 
> 
> I'd be surprised. If you rephrase less strongly, then perhaps. Our needs 
> aren't THAT different.
> 
>> Therefore, please make sure that all discussion is (cross)posted to 
>> the public-ietf-collation@w3.org list. This at least gives people from 
>> other venues a chance to comment; if they miss that chance, then 
>> that's their fault.
> 
> 
> Will try. And at least I'll mention every change loudly and clearly.
> 
> Arnt
> 
> 
> 
> 
Received on Thursday, 22 September 2005 15:13:27 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 14:12:54 GMT