XSLT xsl:sequence. What is it good for..?

Question

I know the following question is a little bit of beginners but I need your help to understand a basic concept.

I would like to say first that I\'m a XSLT programmer

Answer 1

Well to return a value of a certain type you use xsl:sequence as xsl:value-of despite its name always creates a text node (since XSLT 1.0). So in a function body you use

to return an xs:integer value, you would use

to return an xs:string value and

to return an xs:date value and so on. Of course you can also return sequences with e.g. .

You wouldn't want to create a text node or even an element node in these cases in my view as it is inefficient.

So that is my take, with the new schema based type system of XSLT and XPath 2.0 a way is needed to return or pass around values of these types and a new construct was needed.

[edit]Michael Kay says in his "XSLT 2.0 and XPath 2.0 programmer's reference" about xsl:sequence: "This innocent looking instruction introduced in XSLT 2.0 has far reaching effects on the capability of the XSLT language, because it means that XSLT instructions and sequence constructors (and hence functions and templates) become capable of returning any value allowed by the XPath data model. Without it, XSLT instructions could only be used to create new nodes in a result tree, but with it, they can also return atomic values and references to existing nodes.".