Alan’s (Old) Blogometer

I was making a project of reading the language specifications for the languages that I’m using every day. XPath 1.0 and XPath 2.0 Data Model is where I left off. I was working my way back from the XSLT 2.0, which referenced XPath, which in turn references the Data Model.

These are more of my notes on The Data Model, and .

I’m going to note that I asked about Collection Values Sub-expressions on XML-DEV and got answers that clarified my understanding of that part of the requirements. (See older post, which also included a run through of The XPath Requirements Version 2.0.)

2.1 Terminology - This defines every instance of the data model as a sequence. It described atomic values as instances of atomic types. Atomic types are primitives, xdt:dayTimeDuration, and xtd:yearMonthDuration. This section makes reference to URI, and to IRI, or Internaionalized Resource Identifiers, a spec I’d not yet heard of.

2.3 Node Identity - Each node has a unqiue identity. Atomic values do not have a unique identity. A nodes unique identity is not to be confused with the concept of an author assigned unique ID.

2.4 Document Order - Where relevant order is implementation dependant, is it still stable, meaning that the order will not change during processing.

Namespace nodes come after the element, and before attribute nodes.

Relative order of distrinct trees is implementation defined, except that all the nodes in one tree are before or after all the nodes in another tree. I’m repeating this statement of the obvious, since it may apply to Momento.

2.5 Sequences -

This entry was posted on Friday, September 16th, 2005 at 11:11 am and is filed under Software, Programming. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.