Comprehensive Ruby Programming

Breaking down the LSP

If that's about as clear as mud, don't worry; this principle isn't for the faint of heart. It helped me tremendously to break the definition apart, so let's give that a shot.

We'll start with the fact that we know we're going to be working with replacing instances of classes.

Next we know that we're going to be working with parent and child classes. This tells me that the principle revolves around object-oriented inheritance.

Lastly, it sounds like programs have to be able to allow for child class instances to seamlessly replace parent classes. This tells me that we need to focus on the messages that are sent along with ensuring that our parent and child classes can't have requirements that would cause conflicts.

Still ...