initial; first section

hello-world/src/main.rs

@@ -0,0 +1,24 @@
+extern crate tokio;
+
+use tokio::io;
+use tokio::net::TcpStream;
+use tokio::prelude::*;
+
+fn main() {
+    let addr = "127.0.0.1:6142".parse().unwrap();
+
+    let client = TcpStream::connect(&addr).and_then(|stream| {
+        println!("created stream");
+
+        io::write_all(stream, "hello world\n").then(|result| {
+          println!("wrote to stream; success={:?}", result.is_ok());
+          Ok(())
+        })
+    })
+    .map_err(|err| {
+        println!("connection error = {:?}", err);
+    });
+    println!("About to create the stream and write to it...");
+    tokio::run(client);
+    println!("Stream has been created and written to.");
+}