Returns the prefixes of the in-scope namespaces for $element. For namespaces that have a prefix, it returns the prefix as an xs:NCName. For the default namespace, which has no prefix, it returns the zero-length string.

declare namespace a="a"
declare namespace b="b"

let $x := <a:hello>hello
            <b:goodbye>goodbye</b:goodbye>
	  </a:hello>
return
fn:in-scope-prefixes($x)

=> a

declare namespace a="a"
declare namespace b="b"

let $x := <a:hello>hello
            <b:goodbye>goodbye</b:goodbye>
	  </a:hello>
return
fn:in-scope-prefixes($x/b:goodbye)

=> b a

Returns an xs:NCName representing the local part of $arg. If $arg is the empty sequence, returns the empty sequence.

fn:local-name-from-QName(
   fn:QName("http://www.example.com/example", "person") )

=> person 

Returns the namespace URI of one of the in-scope namespaces for $element, identified by its namespace prefix.

If $element has an in-scope namespace whose namespace prefix is equal to $prefix, it returns the namespace URI of that namespace. If $prefix is the zero-length string or the empty sequence, it returns the namespace URI of the default (unnamed) namespace. Otherwise, it returns the empty sequence.

Prefixes are equal only if their Unicode code points match exactly.

declare namespace ex="http://www.example.com/example"

let $x := <ex:hello>1</ex:hello>
return
fn:namespace-uri-for-prefix("ex", $x)
 
=> the namespace URI corresponding to
   "http://www.example.com/example".   

Returns the namespace URI for $arg as an xs:string. If $arg is the empty sequence, the empty sequence is returned. If $arg is in no namespace, the zero-length string is returned.

fn:namespace-uri-from-QName(
  fn:QName("http://www.example.com/example", "person") ) 
 
=> the namespace URI corresponding to
   "http://www.example.com/example". 

Returns an xs:NCName representing the prefix of $arg. The empty sequence is returned if $arg is the empty sequence or if the value of $arg contains no prefix.

declare namespace ex="http://www.example.com/example"

fn:prefix-name-from-QName(
   fn:QName("http://www.example.com/example", "person") )

=> ex 

Returns an xs:QName with the namespace URI given in $paramURI. If $paramURI is the zero-length string or the empty sequence, it represents "no namespace"; in this case, if the value of $paramQName contains a colon (:), an error is raised [err:FOCA0002]. The prefix (or absence of a prefix) in $paramQName is retained in the returned xs:QName value. The local name in the result is taken from the local part of $paramQName.

If $paramQName does not have the correct lexical form for xs:QName an error is raised [err:FOCA0002].

Note that unlike xs:QName this function does not require an xs:string literal as the argument.

fn:QName("http://www.example.com/example", "person") 

=> an xs:QName with namespace URI = 
   "http://www.example.com/example", 
   local name = "person", and
   prefix = "". 

fn:QName("http://www.example.com/example", "ht:person")

=> an xs:QName with namespace URI = 
   "http://www.example.com/example", 
   local name = "person",
   and prefix = "ht".

Returns an xs:QName value (that is, an expanded-QName) by taking an xs:string that has the lexical form of an xs:QName (a string in the form "prefix:local-name" or "local-name") and resolving it using the in-scope namespaces for a given element.

Sometimes the requirement is to construct an xs:QName without using the default namespace. This can be achieved by writing:

     if ( fn:contains($qname, ":") ) 
     then ( fn:resolve-QName($qname, $element) ) 
     else ( fn:QName("", $qname) )

If the requirement is to construct an xs:QName using the namespaces in the static context, then the xs:QName constructor should be used.

If $qname does not have the correct lexical form for xs:QName an error is raised [err:FOCA0002].

If $qname is the empty sequence, returns the empty sequence.

More specifically, the function searches the namespace bindings of $element for a binding whose name matches the prefix of $qname, or the zero-length string if it has no prefix, and constructs an expanded-QName whose local name is taken from the supplied $qname, and whose namespace URI is taken from the string value of the namespace binding.

If the $qname has a prefix and if there is no namespace binding for $element that matches this prefix, then an error is raised [err:FONS0004].

If the $qname has no prefix, and there is no namespace binding for $element corresponding to the default (unnamed) namespace, then the resulting expanded-QName has no namespace part.

The prefix (or absence of a prefix) in the supplied $qname argument is retained in the returned expanded-QName, as discussed in Section 2.1 Terminology[DM].

Assume that the element bound to $element has a single 
namespace binding bound to the prefix "eg". 

fn:resolve-QName("hello", $element) 

=> a QName with local name "hello"
   that is in no namespace. 

fn:resolve-QName("eg:myFunc", $element) 

=> an xs:QName whose namespace URI is specified 
   by the namespace binding corresponding to the 
   prefix "eg" and whose local name is "myFunc".