Type Alias CommandHandler 

pub type CommandHandler = Arc<dyn Fn(&str, Vec<String>) -> Pin<Box<dyn Future<Output = Result<String, CommandError>> + Send>> + Send + Sync>;

Type alias for async command handlers

Commands receive:

• The command name (for handlers that serve multiple commands)
• Command arguments as a vector of strings

Commands return:

• A result containing either a String output or a CommandError

Aliased Type

pub struct CommandHandler { /* private fields */ }