Re: [xml-dev] isXPath1 / isXPath2 -- not(/..)

OK, I think I can explain this.

This XSLT 2.0 transformation:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>

<xsl:template match="/">
<xsl:copy-of select="/.. instance of item()*"/>
<xsl:copy-of select="(4=5)=/.."/>
</xsl:template>
</xsl:stylesheet>

produces:

true false

The **general comparison**:

(4=5) = /..

is equivalent to:

false() = ()

On the left side we have a sequence of one item.

On the right side we have a sequence of 0 items.

Therefore the second (empty) sequence has no item that is the Boolean false() and thus the expression evaluates to false()

On Sat, Dec 19, 2015 at 9:49 AM, Dimitre Novatchev <dnovatchev@gmail.com> wrote:

On Sat, Dec 19, 2015 at 9:22 AM, Hermann Stamm-Wilbrandt <STAMMW@de.ibm.com> wrote:
"(4=5)=/.."

There seems to be something wrong with the type evaluation of Saxon 9.1J

When I evaluate this:

/.. instance of item()

the result is:

false()

As item() is the root of the type system and every possible value is an item(), the above result means that /.. has type that isn't defined anywhere in the type system.

Seems this has something to do with the "highest possible derived type", or is just a bug.

Also, we do need a type-of(expr) function.

Any thoughts, please?

--
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.