RE: [xri] XRI Resolution 2.0 Draft 09 comments

Wil,

Congratulations on setting the record for the fastest spec feedback turnaround time ever!

This is very helpful – you clearly read it closely (and caught several errors). See responses marked ### inline below.

=Drummond

From: Tan, William [mailto:William.Tan@neustar.biz]
Sent: Friday, November 11, 2005 8:07 AM
To: xri@lists.oasis-open.org
Subject: [xri] XRI Resolution 2.0 Draft 09 comments

Hi all,

Here are my comments/suggestions/questions regarding the newly submitted draft. Please let me know if I’ve misread something.

1. xrd:XRD/xrd:Service/xrd:Pattern – what flavor of regular expression should the value be (perl-compatible, posix, etc.)? Is the full power of regexp really required, why not just simple string comparison or prefix matching?

### Great question. Dave was the original proposer of this feature – I'll let him answer (others, please chime in on this.) I know you're working on very high-volume HTTP proxy resolvers – what's your view of the best tradeoff between comparison functionality and performance? ###

2. Line 393 – how about wording it like “A synonym is an XRI that, in its normalized form, differs from another normalized XRI, but which identifies the same target resource …”? Just to make it clear that an un-normalized XRI and its normalized version are not synonyms.

## MUCH better. Thank you. ###

3. If table 4 and 5 on pages 13 and 14 can be combined so both examples show up side-by-side it would help readability a great deal. Perhaps removing the “www.” from the xref root may save some space.

### Will do. ###

4. Section 2.8 Versioning - if the version attribute is optional, implementations may take the shortcut to ignore its presence thereby defeating the purpose of versioning. A newer version may not change the schema but we may want the possibility of modifying the semantics of the elements or attributes. We may not have that choice should implementations do not respect version information.

### Good point. So you believe it should be required. Gabe? Dave? ###

5. Section 6.3 – why MUST the proxy resolution server perform lookahead resolution? Why can’t it perform subsegment-by-subsegment resolution?

### Terminology mistake. What's meant is that the proxy resolver must look up all the authority subsegments on behalf of the client. That's not really lookahead, is it? We'll fix this in WD10.###

6. Section 3.2.7 – What’s the difference between <Synonym xref=”true”> and <XSynonym>?

### That's an error – holdover from an interim revision. <XSynonym> replaced the proposal for <Synonym xref=”true”> (adding an explicit element was judged easier than having to parse an attribute).

Wil

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