How to distinguish processing using Table Dispatch from processing through Message Dispatch?

Table Dispatch and Message Dispatch are two approaches to method invocation or message handling in object-oriented systems, especially in iOS/macOS.

• Message Dispatch (messages) is the dynamic sending of messages to objects, characteristic of Objective-C. When a method is called, the system looks up its implementation at runtime, allowing flexible overriding and interception of calls.

• Table Dispatch is a more static way of calling methods, where function addresses are stored in a table (e.g., a virtual function table in C++). The call is made through direct table access, which is faster but less flexible.

In iOS:

• Objective-C uses Message Dispatch — dynamic message sending.
• Swift by default uses Table Dispatch for methods, providing better performance.

Thus, the main difference:

• Message Dispatch is dynamic, flexible, but slower.
• Table Dispatch is static, fast, but less flexible.

The choice depends on the performance requirements and the desired dynamism of the application's behavior.