Re: [xsl] Why? A function that computes atomic values should use xsl:sequence rather than xsl:value-of

["Martin Honnen martin.honnen@xxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Am 31.03.2020 um 15:40 schrieb Costello, Roger L. costello@xxxxxxxxx:

> I have a function that returns a xs:boolean. I used xs:value-of to return
the value. Saxon 9.9.1.5 gives this warning message:
> 	A function that computes atomic values
> 	should use xsl:sequence rather than
> 	xsl:value-of
>
> Why?
>
> Why should a function use xsl:sequence?

xsl:value-of is an XSLT 1.0 construct that keeps its semantics in 2.0
and 3.0, it creates a text node with the string value of the selected
expression.

Thus, if you want to return a boolean value computed in the selected
expression, use

   <xsl:sequence select="..."/>

as that will return that boolean value and not create and return a text
node with the string representation of the boolean value (that might be
casted back to a boolean if your `xsl:function` also declares
`as="xs:boolean"`).