And there you have it: we've just shown you the implementation of this Person class. Its interface would be its documentation. Usually this means putting it in pod (``plain
old documentation'') format right there in the same file. In our Person
example, we would place the following docs anywhere in the Person.pm file.
Even though it looks mostly like code, it's not. It's embedded
documentation such as would be used by the pod2man, pod2html, or pod2text
programs. The Perl compiler ignores pods entirely, just as the translators
ignore code. Here's an example of some pods describing the informal
interface: