examples/net/echo_client.nv - main - nv-lang/nova

examples/net/echo_client.nv

50 строк2 KB

Evgeniy Golovin

std(№492): write_str удалён, 13 носителей на .write(); спека приведена к реализации; №493-496, план 257

09 авг 2026, 02:46

09 авг 2026, 02:461ce43d8

// SPDX-License-Identifier: MIT OR Apache-2.0
// Echo client example. Connects to an echo server, sends a message, reads
// the echo back. Demonstrates TcpStream.connect + write + read.
//
// Usage (start echo_server.nv first):
//   nova build examples/net/echo_server.nv -o echo_server && ./echo_server &
//   nova build examples/net/echo_client.nv -o echo_client && ./echo_client
//
// See also: examples/net/echo_server.nv

module net.echo_client

import std.net.{SocketAddr, TcpStream, real_net}

const PORT u16 = 7777
const MESSAGE = "hello from nova"

fn main() {
    with Net = real_net() {
        ro addr = SocketAddr.loopback(PORT)
        supervised {
            spawn {
                match TcpStream.connect(addr) {
                    Err(_) => {
                        println("Connect failed — is echo_server running on port ${PORT}?")
                    }
                    Ok(consume stream) => {
                        println("Connected to ${PORT}")

                        match stream.write(MESSAGE) {
                            Err(_) => { println("Write failed"); stream.close() }
                            Ok(_) => {
                                match stream.read_bytes(256) {
                                    Err(_) => { println("Read failed"); stream.close() }
                                    Ok(echo_bytes) => {
                                        ro eb []u8 = echo_bytes
                                        ro echo = unsafe { eb.to_str_unchecked() }
                                        println("Echo: ${echo}")
                                        stream.close()
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    println("Done.")
}