[tei-council] Examples for certainty|precision @match

[James Cummings]

On 29/11/12 11:11, Gabriel Bodard wrote:
> That rings a bell. :-) So in the absence of @xml:base, the starting
> point for any xpointer in @target is root. (Which was an aside anyway.)
>
> There are two questions re the starting point for xpath in @match:
>
> 1. What is the starting point assumed to be for any @match (in the
> absence of @target)? The guidelines say current element, but some
> examples in CE seem to assume the element's parent;

The guidelines explicitly say the opposite of this surely?  They 
say things like:

"When no target is specified, by default the proposed certainty 
applies to its parent element, in this case the placeName 
element. The match attribute discussed below may be used to 
further vary this behaviour."

and

"As previously noted, if no value is supplied for target, the 
context within which the value of match should be evaluated is 
the parent element of the certainty element itself."

It is only on the reference page for att.scoping that it says 
that @match:

"supplies an arbitrary XPath expression identifying a set of 
nodes, selected within the context identified by the target 
attribute if this is supplied, or within the context of the 
element bearing this attribute if it is not."

I would contend that this should just be changed to "or within 
the context of the parent of the element bearing this attribute 
if it is not." (or something even clearer!)

> 2. What is the assumed context of any certainty|precision element in the
> absence of @match (and @target)? The guidelines say current element's
> parent, which I feel is slightly unintuitive alongside the official
> answer to question 1.

I think to say one of these is 'official' and the other isn't is 
a bit misleading. ;-)

> There are then 4 possible solutions to this:

I would vote for b.

-James


>    a. context is always current element, so most @match attributes will
> begin "../", but other possibilities such as match="preceding::lb[1]"
> are possible. This may be the most strictly rational solution, although
> not the most popular, as far as conversation so far indicates. (Plus,
> and more importantly, I bet no one actually uses xsl:evaluate to
> interpret the content of @match as XPath...)
>
>    b. context is always parent of current element, so @match can often be
> omitted, and most examples in the Guidelines showing values such as
> match="@reason" are correct. This is also nice and consistent, if
> slightly more limiting (but in a good way: a certainty element can no
> longer refer to itself), and also convenient for anyone who doesn't want
> to have to evaluate document-source XPath on the fly, but just embed
> certainty|precision inside the qualified element and treat it as an
> "enhanced attribute".
>
>    c. context is current if there is content in @match (and no @target),
> parent if there is not: status quo; examples in guidelines need fixing.
> (Slightly unintuitive?)
>
> [d. context is parent if there is content in @match (and no @target),
> current if not: clearly nonsense.]
>
> There are arguments for and against all of a, b and c. In my opinion b
> is the strongest, for the reasons articulated above (and argued by James
> yesterday), but there may be some value to c, the status quo.
>
> Does this express the options clearly, do you think?



-- 
Dr James Cummings, James.Cummings at it.ox.ac.uk
Academic IT Services, University of Oxford