
The function returns a node-set that has the current node as its only member.
For an outermost expression (an expression not occurring within another expression),
the current node is always the same as the context node. For an expression
occuring within another expression, e.g. within predicate in some path,
the current node is the same as the context node of the first step in the path.

Please refer XSL standard before the first use of this function,
to understand exact difference between "current" and "context" node.

XSLT 1.0 states that it is an error to use the current() function in a XSL "pattern",
e.g. in "match" attribute of <xsl:key> element, because patterns
have no value assigned for current node assigned processing.
Instead of reporting the error, Virtuoso@s XSLT processor uses context node
if current node is not set.
