Hello everybody,

This may be a stupid question, but i've been banging my brain against it 
all afternoon, and as such i'm no longer think good.

Given this XML:

<table id="mytable">
 	<tr>
 		<td class="left">port</td>
 		<td class="right">starboard</td>
 	</tr>
 	<tr>
 		<td class="left">gauche</td>
 		<td class="right">droite</td>
 	</tr>
 	<tr>
 		<td class="left">sinister</td>
 		<td class="right">dexter</td>
 	</tr>
</table>

(a) Should this XPath expression find the cell containing 'starboard':

table[@id='mytable']/tr[1]/td[@class='right']

(b) Should these XPath expressions (i) mean the same thing and (ii) find 
the cell containing 'starboard':

(1) table[@id='mytable']/tr/td[@class='right'][1]
(2) table[@id='mytable']//td[@class='right'][1]
(3) table[@id='mytable']//td[@class='right' and position()=1]

?

I wrote some code on the assumption that the answer to (b)(ii) was 'yes', 
but it didn't work. I'm not sure if this is a mistaken assumption on my 
part, a failure to translate a correct assumption into correct code, or a 
bug in my XPath library (Xalan 2.7.1).

My thinking had been that if you have an expression E that identifies a 
node set, then E[n] selects the nth node of that set. But fiddling and 
reading, it dawned on me that this isn't the case, but rather that E[n] 
means the members of E which are the nth child of their parents - in this 
case, the tr elements. That would be fine, but what i found rather 
counterintuitive is that example (b)(2), which is the form of expression i 
was using, contains no explicit mention of any tr, and so that means 
you're indexing into completely mysterious parent elements!

In conclusion, sometimes i love XPath, and sometimes i hate it.

Thanks,
tom

-- 
I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth. -- Umberto Eco