Re: [xsl] Why does my XSLT produce a Warning message with never-executed code that divides a blank by 10?

["Michael Kay michaelkay90@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Usual problem when technology tries to be smart but isn't quite smart enough.

Saxon is smart enough to work out that if `xs:integer($test)` is ever
evaluated then it will give a failure. It's not smart enough to work out that
the expression will never be evaluuated. Well, actually it is, but it only
works that out AFTER outputting the warning. Clearly there's scope for
improvement.

On the other hand, your code is a rather convoluted way of writing

<xsl:template match="/"/>

so a warning is not entirely inappropriate.

But you say it's generated code, and it's very normal for generated code to
produce all sorts of warnings. We generate C# code for the SaxonCS product and
the simplest way to avoid zillions of warnings is simply to switch them off
(which C# allows us to do selectively).

Michael Kay
Saxonica

> On 31 Mar 2024, at 08:56, Roger L Costello costello@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hi Folks,
>
> I have a program that generates this XSLT code:
>
> <xsl:template match="/">
>        <xsl:variable name="test" select="'    '" as="xs:string"/>
>        <xsl:value-of select="
>            if (normalize-space($test) eq '') then ()
>            else xs:integer($test) div 10"/>
> </xsl:template>
>
> When I execute that XSLT code, I get this warning message:
>
> Warning: SXWN9000  Evaluation will always throw a dynamic error: Cannot
convert zero-length string to an integer
>
> Why am I getting that Warning message? This:
>
> xs:integer($test) div 10
>
> will never be executed because of this:
>
> if (normalize-space($test) eq '') then ()
>
> So I don't understand why I am getting the Warning message.
>
> How can the XSLT code be written so that, when executed, it doesn't produce
a Warning message? Note: recall that I have a program that generates the XSLT
code. Sometimes the program generates $test with a blank value, other times
the program generates $test with a numeric value. The generated XSLT code
needs to work with both cases.
>
> /Roger