Error "System function unparsed-text#1 is not available with this host language"

I'm using Saxon to execute the following xquery;

fn:unparsed-text("text.txt")

But I'm getting the following error me开发者_运维技巧ssage;

javax.xml.xquery.XQException:
System function unparsed-text#1 is not available with this host language

What does that error message mean?

The unparsed-text() function is an XSLT 2.0 - only function. It isn't an XPath 2.0 function.

Hopefully, this may change in XPath 3.0.

Because you are using Saxon, you may try to use the saxon extension function saxon:transform() and in the transformation invoke unparsed-text().