Do files and a chunk of XML have a 1-1 mapping?
You could try using closures like so. (Untested)

sub make_iterative (\@) {
    my $count = 0;
    my $arrayref = shift;
    return sub {
            return $count < @$arrayref ? undef : $arrayref->[$count++]
+;
        };
}


my @files = get_files();
my $iter = make_iterative(@files);

print xml_header();

while (my $el = $iter->()){    
    print Chunk2XML($el);     
}
print xml_footer();
[download]

Using closures , you can probably fit it into your framework. I just used print because I'm not exactly sure what you're doing codewise.

-Lee

"To be civilized is to deny one's nature."