Dimitre wrote:
> While your mapping operator will perform a series of
> mappings, each producing an
> intermediate sequence and may require too much memory, the
> last function applies the
> map function only once. The composition of all functions is
> applied on every element
> of $sequence and the resulting sequence is produced. No
> additional memory for
> intermediate sequences is necessary.
>
> This shows that it is better to have a map() function and a
> composition operator for
> expressions (in case XPath 2.0 will not fully support
> higher-order functions).
>
As a point of information, the implementation of "for" expressions in Saxon
7.0 is fully pipelined, so there will never be a need to store intermediate
sequences in memory.

Mike Kay


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list