Wow! rustyline has intensive support for a lot of the actions and things the user can do. Though I wanted to provide a more restrictive yet powerful abstraction that’s my I chose a trait based approach. It provides the exact control needed on certain aspects of the shell while providing ample control because of the shared state. Initially, I was planning to make the functions async, but I rather choose to pass the async runtime instead. It solves for 2 cool use-cases; 1 we can call block_on and manage an async task in the flow, or 2 queue in the action and consider pooling it when needed.