[arunix]

OO in Perl is lower level compared to Java or C++, so e.g. instead of having a class construct, you have to simulate a class - typically by binding (blessing) a data structure to a namespace. Then any functions in the namespace become methods that can be called via the data structure (object).

In practice, this has turned out to be a mixed blessing because of how tedious it is to do this repeatedly. So over the years there have been many libraries created to make this easier, each with different features.

There's currently work underway to modernise Perl's built in OO to address these problems.

On the other hand, this makes some things easier, e.g. Design by Contract can be added to Perl just by writing a library.

Another example, adding traits to PHP required updating PHP itself, whereas in Perl there are libraries to do that.