Re: [xsl] Seek an XPath 2.0 expression for checking that each object in a file system has one parent

["Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Finally:

  empty($vF-Ids[index-of($vF-Ids,.)[2]])

where the $vF-Ids sequence is:

  //*/name()[starts-with(., 'F')]

Here is a small XSLT 2.0 transformation to use to evaluate these expressions:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
 <xsl:output method="text"/>

  <xsl:variable name="vFNames" select="//*/name()[starts-with(., 'F')]"/>

 <xsl:template match="/">
    <xsl:sequence select=    "empty($vFNames[index-of($vFNames,.)[2]])"/>
  </xsl:template>
</xsl:stylesheet>

When applied on the provided XML document:

<Root>

                <D1>

                                <D2/>

                                <F1/>

                </D1>

                <D2>

                                <F2/>

                                <F1/>

                </D2>

</Root>

the result is:

  false


When applied on this XML document (the second <F1/>  has been renamed to <F3>:

<Root>

                <D1>

                                <D2/>

                                <F1/>

                </D1>

                <D2>

                                <F2/>

                                <F3/>

                </D2>

</Root>

the result is:

  true


In XPath 3 one can use:

let $vFNames := //*/name()[starts-with(., 'F')]
  return
     empty($vFNames[index-of($vFNames,.)[2]])


or (if you like more the previous expression):

let  $vFNames := //*/name()[starts-with(., 'F')]
  return
      count($vFNames) eq count(distinct-values($vFNames))

Cheers,
Dimitre

On Sun, Oct 16, 2016 at 5:59 PM, Dimitre Novatchev <dnovatchev@xxxxxxxxx> wrote:
>>   count(//*[starts-with(name(), 'F')])
>> eq
>>   count(distinct-values(//*[starts-with(name(), 'F')]/name()))
>
> Just a little bit shorter:
>
>      count(//*[starts-with(name(), 'F')])
>     eq
>      count(distinct-values(//*/name()[starts-with(., 'F')]))
>
>
> Cheers,
> Dimitre
>
> On Sun, Oct 16, 2016 at 5:56 PM, Dimitre Novatchev <dnovatchev@xxxxxxxxx> wrote:
>>   count(//*[starts-with(name(), 'F')])
>> eq
>>   count(distinct-values(//*[starts-with(name(), 'F')]/name()))
>>
>>
>> This is just a first try. There could be even a shorter expression.
>>
>>
>> Cheers,
>> Dimitre.
>>
>> On Sun, Oct 16, 2016 at 4:29 PM, G. Ken Holman g.ken.holman@xxxxxxxxx
>> <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>>> I see that you are dealing with only the names of the grandchildren of the
>>> root.  The vollowing has three solutions, one based on the names (as you
>>> have done) and two that are namespace-safe.  The latter two are equivalent,
>>> but since the operators "every" and "some" didn't come to mind for you, I
>>> thought I would illustrate both.
>>>
>>> The second two work with axes the way you were getting started.  But for the
>>> first I think you can rephrase your problem to be not that all elements have
>>> one parent but that there is only one of every element ... which I think is
>>> equivalent given the limited amount of information regarding your objective.
>>>
>>> I hope this helps.
>>>
>>> . . . . . . Ken
>>>
>>> ~/t/ftemp $ cat roger1.xml
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <Root>
>>>     <D1>
>>>         <D2/>
>>>         <F1/>
>>>     </D1>
>>>     <D2>
>>>         <F2/>
>>>     </D2>
>>> </Root>
>>> ~/t/ftemp $ cat roger2.xml
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <Root>
>>>     <D1>
>>>         <D2/>
>>>         <F1/>
>>>     </D1>
>>>     <D2>
>>>         <F2/>
>>>         <F1/>
>>>     </D2>
>>> </Root>
>>> ~/t/ftemp $ xslt2 roger1.xml roger.xsl
>>> true
>>> true
>>> true
>>> ~/t/ftemp $ xslt2 roger2.xml roger.xsl
>>> false
>>> false
>>> false
>>> ~/t/ftemp $ cat roger.xsl
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
>>>   xmlns:xs="http://www.w3.org/2001/XMLSchema";
>>>   exclude-result-prefixes="xs"
>>>   version="2.0">
>>>
>>> <xsl:output method="text"/>
>>>
>>> <xsl:template match="/">
>>>   <xsl:value-of select="
>>>     count(/Root/*/*)=count(distinct-values(/Root/*/*/name(.)))"/>
>>>   <xsl:text>&#xa;</xsl:text>
>>>   <xsl:value-of select="
>>>     every $elem in /Root/*/* satisfies
>>>           not($elem/following::*[not(*)]/node-name(.)=node-name($elem))"/>
>>>   <xsl:text>&#xa;</xsl:text>
>>>   <xsl:value-of select="
>>>     not( some $elem in /Root/*/* satisfies
>>>               $elem/following::*[not(*)]/node-name(.)=node-name($elem))"/>
>>>   <xsl:text>&#xa;</xsl:text>
>>> </xsl:template>
>>>
>>> </xsl:stylesheet>
>>> ~/t/ftemp $
>>>
>>>
>>>
>>> At 2016-10-16 22:33 +0000, Costello, Roger L. costello@xxxxxxxxx wrote:
>>>>
>>>> Hi Folks,
>>>>
>>>> I am modeling a file system. Below is a sample instance. D1 means
>>>> Directory 1, F1 means File 1, etc. The instance says this: the content of
>>>> directory 1 is directory 2 and file 1. The content of directory 2 is file 2.
>>>> Stated another way, directory 2 and file 1 are contained in directory 1, and
>>>> file 2 is contained in directory 2.
>>>>
>>>> <Root>
>>>>     <D1>
>>>>         <D2/>
>>>>         <F1/>
>>>>     </D1>
>>>>     <D2>
>>>>         <F2/>
>>>>     </D2>
>>>> </Root>
>>>>
>>>> I want an XPath 2.0 expression which returns true if each object has one
>>>> parent. An "object" is a directory or a file. In the example above each
>>>> object has one parent, so the XPath should return true. Below is an illegal
>>>> file system because F1 has two parents: D1 and D2.
>>>>
>>>> <Root>
>>>>     <D1>
>>>>         <D2/>
>>>>         <F1/>
>>>>     </D1>
>>>>     <D2>
>>>>         <F2/>
>>>>         <F1/>
>>>>     </D2>
>>>> </Root>
>>>>
>>>> The XPath should return false.
>>>>
>>>> This XPath is almost correct:
>>>>
>>>> for $i in /Root/* return for $j in $i/* return not(name($j) =
>>>> $i/following-sibling::*/*/name())
>>>>
>>>> I say it is "almost" correct because it returns multiple Booleans, not a
>>>> single Boolean result.
>>>>
>>>> Two Questions:
>>>>
>>>> 1. What is the correct XPath expression?
>>>> 2. Is there a different way to model in XML a file system that would
>>>> enable a simple XPath expression?
>>>>
>>>> /Roger
>>>
>>>
>>>
>>> --
>>> Check our site for free XML, XSLT, XSL-FO and UBL developer resources |
>>> Streaming hands-on XSLT/XPath 2 training @US$45: http://goo.gl/Dd9qBK |
>>> Crane Softwrights Ltd. _ _ _ _ _ _ http://www.CraneSoftwrights.com/s/ |
>>> G Ken Holman _ _ _ _ _ _ _ _ _ _ mailto:gkholman@xxxxxxxxxxxxxxxxxxxx |
>>> Google+ blog _ _ _ _ _ http://plus.google.com/+GKenHolman-Crane/posts |
>>> Legal business disclaimers: _ _ http://www.CraneSoftwrights.com/legal |
>>>
>>> 
>>
>>
>>
>> --
>> 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.



-- 
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.