Tests whether the language of the context item as specified by xml:lang attributes is the same as, or is a sublanguage of, the language specified by $lang. The behavior of the function if the second argument is omitted is exactly the same as if the context item (.) had been passed as the second argument. The language of the argument node, or the context item if the second argument is omitted, is determined by the value of the xml:lang attribute on the node, or, if the node has no such attribute, by the value of the xml:lang attribute on the nearest ancestor of the node that has an xml:lang attribute. If there is no such ancestor, then the function returns false().
The following errors may be raised: if the context item is undefined [err:XPDY0002]XP; if the context item is not a node [err:XPTY0004]XP.
If $lang is the empty sequence it is interpreted as the zero-length string.
$lang
The language code
Returns true if the language code matches, false otherwise
lang($lang as xs:string?, $node as node()) xs:boolean
Tests whether the language of $node as specified by xml:lang attributes is the same as, or is a sublanguage of, the language specified by $lang. The behavior of the function if the second argument is omitted is exactly the same as if the context item (.) had been passed as the second argument. The language of the argument node, or the context item if the second argument is omitted, is determined by the value of the xml:lang attribute on the node, or, if the node has no such attribute, by the value of the xml:lang attribute on the nearest ancestor of the node that has an xml:lang attribute. If there is no such ancestor, then the function returns false().
The following errors may be raised: if the context item is undefined [err:XPDY0002]XP; if the context item is not a node [err:XPTY0004]XP.
If $lang is the empty sequence it is interpreted as the zero-length string.
$lang
The language code
$node
The node
Returns true if the language code matches, false otherwise
