Subject: Re: [xsl] position last and attributes From: Ihe Onwuka <ihe.onwuka@xxxxxxxxxxxxxx> Date: Thu, 20 Sep 2012 10:53:30 +0100 |
On Thu, Sep 20, 2012 at 9:53 AM, Andrew Welch <andrew.j.welch@xxxxxxxxx> wrote: >>> The fact the order of attributes cannot be guaranteed has nothing to >>> do with position() and last(), as by the time those functions get to >>> be used the order of the node list is known. >>> >> >> My initial post (if you read it again) was to highlight the paradox of >> being able to apply ordering semantics to something that is >> intrinsically unordered. > > There's nothing to highlight... > > - attribute order is not guaranteed: this just means 2 different > conformant implementations could return attributes in different orders > to each other (or theoretically even themselves) > > - position() returns the position of a node within a node list, last() > returns the last node in a node list > > The two things are unrelated (or orthogonal! knew I would use that > word one day...) > What is orthogonal is the conversation. You are talking about position() and last() through the prism of the XPath data model (or specification if it is more accurate to say that). If you cast a data model in it's real light; as an imperfect abstraction of the real world, then one can see how the imperfections can lead to paradoxes such as being able to apply a function that has ordering semantics to another construct that is intrinsically unordered. Let me give a different example. Where does a circle begin? Does that stop a programming language from applying a function start() to it's representation of the concept of a circle and yielding a definitive answer. Suppose for arguments sake that circle.start() is defined to yield the northernmost coordinate of the circle. Is that then the universal truth or have we uncovered a paradox in that something that definitively has no start or end nonetheless yields a definitive answer (however derived) when a function start() is applied to it. Is it important that we can tell the difference?
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
Re: [xsl] position last and attribu, Andrew Welch | Thread | Re: [xsl] position last and attribu, Andrew Welch |
Re: Fwd: [xsl] curly braces, Michael Kay | Date | Re: Fwd: [xsl] curly braces, Ihe Onwuka |
Month |