Re: Re: XPath 2.0: Problems with the two boolean const

Hi Jeni,

--- Jeni Tennison <jeni@xxxxxxxxxxxxxxxx> wrote:
> Hi Dimitre,
> 
> > But if the Data Model were saying that 0 and 1 are not simply
> > "string representations" (note that I didn't use '0' and '1' in my
> > previous example but just 0 and 1 -- that is not the strins '0' and
> > '1') but that 0 and 1 are *the* two xs:boolean constants,
> >
> > then
> >
> > it would make difference as the result of evaluating a boolean
> > expression would be not a "representation" but a real (or native, or
> > genuine) boolean value.
> >
> > Isn't it natural for a type to have its own genuine values and not
> > only a "representation"?
> 
> Of course. But that's what we have currently, isn't it? The result of
> the expression:
> 
>   true() and false()
> 
> is a native xs:boolean value, false, not the string 'false'.
> 
> Perhaps you're finding problems because:
> 
>   <xsl:value-of select="true() and false()" />
> 
> generates a text node whose string value is the result of converting
> the xs:boolean value false to a string (i.e. 'false')?
> 
> Perhaps you would be better off using:
> 
>   <xsl:sequence select="true() and false()" />
> 
> which actually adds the xs:boolean value false to the result sequence.
> 
> In other words, use a template along the lines of:
> 
>   <xsl:template name="And" match="test:*" as="xs:boolean">
>     <xsl:param name="arg1" as="xs:boolean"/>
>     <xsl:param name="arg2"  as="xs:boolean"/>
>     <xsl:sequence select="$arg1 and $arg2"/>
>   </xsl:template>
> 
> Note that here the template is declared to have an xs:boolean value as
> its result; that declarations isn't completely necessary (it will
> still have an xs:boolean value as its result without it), but it's
> good practice.
> 
> (Returning the actual xs:boolean value should also be more efficient
> since you're not having to create any nodes that way --
> <xsl:value-of>, theoretically at least, creates a text node.)

Completely agree with you.

In fact this was exactly my first attempt -- I hope that after I get the
new version of Saxon with the bug fixed this will really work.


Thank you once again.



=====
Cheers,

Dimitre Novatchev.
http://fxsl.sourceforge.net/ -- the home of FXSL

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