DVAL expressions return dimension values. The
DVAL PERL expression uses Perl to manipulate the data.
The Perl code is contained in an
EXPRBODY element. The Zinc Perl module provides
classes and methods for gaining access to and manipulating the current record.
Objects accessed from Perl are copies of the current data; changing the Perl
objects has no effect on the current data until a function is called to
explicitly copy the Perl objects back.
See the
EXPRESSION element for DTD and attribute information.
