Simple mapping expressions
XPath 3.0 introduces the "simple mapping" operator !
. The expression
A!B
evaluates expression B
once for each item in the result of
evaluating A
, and concatenates the results. In the case where evaluating
A
returns a sequence of nodes, A!B
has the same effect as
A/B
except that the result is not sorted into document order, and
duplicates are not eliminated.
The semantics of the expression A!B
are precisely equivalent to the XSLT
construct <xsl:for-each select="A"><xsl:sequence
select="B"/></xsl:for-each>
; in Saxon they generate the same internal
code.