<informalexample> to contain one or multiple <programlisting> element(s) fora multi-line source code block?

[Taro Ikai <tikai@ABINITIO.COM>]

http://www.docbook.org/tdg/en/html/informalexample.html

cites an example of <informalexample><programlisting>
block that contains 
several lines of source code block
in a single <programlisting> element:

<informalexample>
<programlisting>
sub print_content_model {
    my($self) = shift;
    local($_) = shift;
    local(*FILE) = shift;

    my(@cm) = $self->format_content_model2($_);
    foreach $_ (@cm) {
        print FILE $self->make_links($_, 1, 1),
"\n";
    }
}
</programlisting>
</informalexample>

My limited understanding of XML is
that it does not pay attention to 
the white spaces or new lines within
CDATA sections. The CYGWIN 
distribution of Tidy, for example,
does not not preserve 
the new lines within CDATA. 

Am I better off to use something like
the following?

<informalexample>
  <programlisting>sub print_content_model
{</programlisting>
  <programlisting>&nbsp;&nbsp;my($self)
= shift;</programlisting>
  <programlisting>&nbsp;&nbsp;local($_)
= shift;</programlisting>
  <programlisting>&nbsp;&nbsp;local(*FILE)
= shift;</programlisting>
  <programlisting>&nbsp;&nbsp;
my(@cm) = $self->format_content_model2($_);</programlisting>
  <programlisting/>
  <programlisting>&nbsp;&nbsp;foreach
$_ (@cm) {</programlisting>
  <programlisting>&nbsp;&nbsp;
   print FILE $self->make_links($_, 1, 1), "\n";</programlisting>
  <programlisting>&nbsp;&nbsp;}</programlisting>
  <programlisting>}</programlisting>
</informalexample>

Taro Ikai