- From: <DPawson@rnib.org.uk>
- Date: Tue, 3 Sep 2002 10:10:10 +0100
- To: w3c-ac-members@w3.org
- Cc: www-tag@w3.org
> Subject: Call for Review: XML-Signature XPath Filter 2.0 From which: <quote> In the interest of simplifying the creation of efficient implementations, the architecture of this transform is not based on evaluating an [XPath] expression for every node of the XML parse tree (as defined by the [XPath] data model). Instead, a sequence of XPath expressions are used to select the roots of document subtrees - location sets, in the language of [XPointer] - which are combined using set intersection, subtraction and union, and then used to filter the input node-set. The principal differences from the XPath transform are: A sequence of XPath operations can be executed in a single transform, allowing complex filters to be more-easily expressed and optimized. The XPath expressions are evaluated against the input document resulting in a set of nodes, instead of being used as a boolean test against each node of the input node-set. To increase efficiency, the expansion of a given node to include all nodes having the given node as an ancestor is now implicit so it can be performed by faster means than the evaluation of an XPath expression for each document node. The resulting node-sets can be combined using the three fundamental set operations (intersection, subtraction, and union), and then applied as a filter against the input node-set, allowing operations such as signing an entire document except for a specified subset, to be expressed more clearly and efficiently. </quote> I thought one of the architectural principles was re-use. With xpath 2.0, most of these differences appear to be resolved. Why can't a little more coordination ensure that xpath can be used for signatures? Regards DaveP. - NOTICE: The information contained in this email and any attachments is confidential and may be legally privileged. If you are not the intended recipient you are hereby notified that you must not use, disclose, distribute, copy, print or rely on this email's content. If you are not the intended recipient, please notify the sender immediately and then delete the email and any attachments from your system. RNIB has made strenuous efforts to ensure that emails and any attachments generated by its staff are free from viruses. However, it cannot accept any responsibility for any viruses which are transmitted. We therefore recommend you scan all attachments. Please note that the statements and views expressed in this email and any attachments are those of the author and do not necessarily represent those of RNIB. RNIB Registered Charity Number: 226227 Website: http://www.rnib.org.uk
Received on Tuesday, 3 September 2002 05:10:32 UTC