Hands-On Microservices with Rust

Executing subcommands

We use the structure of branches to match subcommands from our previous examples:

match matches.subcommand() {    (CMD_ADD, Some(matches)) => {        let token = matches.value_of("TOKEN").unwrap();        let uid = matches.value_of("UID").unwrap();        add_session(&conn, token, uid)?;    }    (CMD_REMOVE, Some(matches)) => {        let token = matches.value_of("TOKEN").unwrap();        remove_session(&conn, token)?;    }    (CMD_LIST, _) => {        println!("LIST");        let sessions = list_sessions(&conn)?;        for (token, uid) in sessions {            println!("Token: {:20}   Uid: {:20}", token, uid);        }    }    _ => { matches.usage(); }}

For the add subcommand, we extract the TOKEN and UID values from arguments and pass them to the add_session function with a reference to a Connector. For the ...