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Re: [xsl] XPath for expressing contiguous elements?

2017-05-01 15:00:38
And here is an XPath 2.0 expression:

empty(/*/B[. >> /*/A[1] and /*/A[last()] >> .])

Making this more general:

       empty(/*/*[not(self::A)][. >> /*/A[1] and /*/A[last()] >> .])


This XPath expression happens to be slightly shorter (by 3 characters)
than the XPath 1.0 expression suggested by Dr. Michael Kay:

     not(*[not(self::A)][following-sibling::A][preceding-sibling::A])



Cheers,
Dimitre



On Mon, May 1, 2017 at 11:42 AM, Dimitre Novatchev 
<dnovatchev(_at_)gmail(_dot_)com> wrote:
And here is an XPath 2.0 expression:

empty(/*/B[. >> /*/A[1] and /*/A[last()] >> .])




On Mon, May 1, 2017 at 5:59 AM, Costello, Roger L. 
costello(_at_)mitre(_dot_)org
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com> wrote:
Hi Folks,

I want an XPath expression that implements this rule:

        All <A> elements shall be contiguous within <Test>.

In this example all A's are contiguous, so the rule is satisfied:

<Test>
    <B/>
    <A/>
    <A/>
    <A/>
    <B/>
</Test>

In this example there is an intervening B, so the rule is not satisfied:

<Test>
    <B/>
    <A/>
    <A/>
    <B/>
    <A/>
    <B/>
</Test>

Below is the XPath that I created. I have two questions about it:

(1) Is it correct? Do you see anything it would fail to catch?

(2) Is there a better (simpler, more efficient) XPath expression?

Here is the XPath (within a Schematron rule):

<sch:rule context="Test">
    <sch:assert test="
        every $i in A satisfies
           (if ($i/preceding-sibling::A) then 
$i/preceding-sibling::*[1][self::A] else true())
           and
           (if ($i/following-sibling::A) then 
$i/following-sibling::*[1][self::A] else true())
        ">
        All A's shall be contiguous within Test.
    </sch:assert>
</sch:rule>




--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
To achieve the impossible dream, try going to sleep.
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
-------------------------------------
Sanity is madness put to good use.
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.



-- 
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
To achieve the impossible dream, try going to sleep.
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
-------------------------------------
Sanity is madness put to good use.
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.
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