Can you explain the internal workings and principles of organizing Table Dispatch in the system?

Table Dispatch is a mechanism for dynamic method invocation based on a table of function pointers (vtable), used to implement polymorphism in object-oriented systems, including iOS (Objective-C and Swift).

Principle of operation:

• A table (vtable) is created for each class, storing addresses of method implementations.
• When a virtual method is called, the object uses a pointer to its vtable to find and invoke the required function.

Organization:

• The table is usually created at compile time or class load time.
• In inheritance, the table can be extended or overridden to support method overriding.

Advantages:

• Fast method calls through direct index access in the table.
• Support for dynamic polymorphism.

Example:

In Swift or Objective-C, calling a method via a pointer to the base class actually involves accessing the vtable, which allows calling an overridden method in a subclass.

Thus, Table Dispatch provides an efficient and flexible mechanism for method invocation at runtime, which is important for dynamic languages and systems with inheritance.