Ovid wants a new perl book. What he really points out is that with the freedom perl gives the programmer, one needs to really grasp the concept of OO if one wants to avoid the pitfalls he mentions. The topics he suggest are essential for _any _book on OO, not just for perl:

  • Responsibility-driven design.
  • The difference between class and instance data/methods.
  • How inheritance breaks encapsulation.
  • When to throw exceptions.
  • Composition via delegation.
  • Class consumers versus class cooperators.
  • Why the Liskov Substitution Principle is important.
  • Polymorphism and allomorphism.