pub fn handlerchain_exercise() -> Result<(), String>Expand description
Example of using the “Handle Chain” or “Chain of Responsibility” design pattern.
The Handler Chain pattern is used to support a dynamic list of handlers that are passed the same arguments. It is kind of the inverse of the Visitor pattern, where the Visitor pattern is a handler that is passed to all objects in a list, while the Handler Chain pattern is an object passed to handlers in a list.
In this exercise, multiple rectangular regions called MessageWindows embody the handlers and the HandlerChain object passes message objects to each MessageWindow until the message is handled.