TIL, 2017-12-02, Chain of Responsibility and Decorator

chain_of_responsibility pattern?
Use Chain of Responsibility when you can conceptualize your program as a chain made up of links, where each link can either handle a request or pass it up the chain.
Decorator: adds new behavior that in effect widens the original interface. COR modifies an existing behavior which is similar to overriding an existing method using inheritance. You can choose to call super.xxx() to continue up the chain or handle the message yourself.
I’d say that a Chain of Responsibility is a particular form of Decorator.
Decorator cons: it can fail code review if it overcomplicates things. Pros: it separates logic such as emails from saving an object. You can save an object, without an email, and you can send an email without sending an object.
Always rescue from StandardError, not Exception.
Bulma, pg_search gems.
Remember: zsh has cdpath to do cd ... autocomplete.