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

Subject: Re: [xsl] Why? A function that computes atomic values should use xsl:sequence rather than xsl:value-of
From: "Graydon graydon@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 31 Mar 2020 13:57:23 -0000
On Tue, Mar 31, 2020 at 01:40:19PM -0000, Costello, Roger L. costello@xxxxxxxxx scripsit:
> Hi Folks,
> 
> 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 returns a text node.

xsl:sequence returns what it has, which at least has the possibility of
being an atomic value in a function that computes atomic values.

So while things work via implicit type conversion, you're getting a
warning to tell you that you're making the optimizer work hard for no
obvious purpose.

-- Graydon

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