Rustのmoduleの話

`mod` and the Filesystem - The Rust Programming Language

mod client {            //
    fn connect(){}      // -> client.rs
}                       //

mod network {           //
    fn connect(){}      //  ------ -> network/mod.rs
                        // |
    mod server {        // |
        fn connect(){}  // | -> network/server.rs
    }                   //  ------
}                       //