From b496a2b2616209ce679abd289567c34782275b53 Mon Sep 17 00:00:00 2001
From: Geoff Shannon <geoffpshannon@gmail.com>
Date: Thu, 31 Jan 2019 14:18:43 -0800
Subject: [PATCH] Add an example showing async usage with tokio

---
 Cargo.toml        |  3 +++
 examples/async.rs | 63 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 examples/async.rs

diff --git a/Cargo.toml b/Cargo.toml
index b9c9781730..b9e4e29fa7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,7 +35,10 @@ winapi = { version = "0.3", features = ["consoleapi", "handleapi", "minwindef",
 env_logger = "0.6"
 tempdir = "0.3"
 assert_matches = "1.2"
+futures = "0.1"
+tokio = "0.1"
 
 [features]
 default = ["with-dirs"]
 with-dirs = ["dirs"]
+
diff --git a/examples/async.rs b/examples/async.rs
new file mode 100644
index 0000000000..7eb8aa62c1
--- /dev/null
+++ b/examples/async.rs
@@ -0,0 +1,63 @@
+use std::sync::mpsc as sync_mpsc;
+use std::thread;
+use std::time::Duration;
+
+use rustyline::error::ReadlineError;
+use rustyline::Editor;
+
+use futures::future::Future;
+use futures::stream::Stream;
+
+use tokio::sync::mpsc as async_mpsc;
+
+fn main() {
+    let timeout = Duration::from_millis(10);
+
+    let (mut stdin_tx, stdin_rx) = async_mpsc::unbounded_channel();
+    let (stdout_tx, stdout_rx) = sync_mpsc::channel();
+
+    let mut editor = Editor::<()>::new();
+
+    let _thread = thread::spawn(move || loop {
+        // Standard usage of the Rustyline editor
+        let line = editor.readline("> ");
+
+        // Decide whether we should quit, otherwise we loop forever.
+        let quit = match &line {
+            Err(ReadlineError::Interrupted) => true,
+            Err(ReadlineError::Eof) => true,
+            _ => false,
+        };
+
+        // Send read lines into the async system
+        stdin_tx.try_send(line).expect("failed to send");
+
+        // Block for a moment to give the async code a chance to run
+        match stdout_rx.recv_timeout(timeout) {
+            Ok(msg) => println!("{}", msg),
+            Err(sync_mpsc::RecvTimeoutError::Timeout) => (),
+            Err(sync_mpsc::RecvTimeoutError::Disconnected) => break,
+        }
+
+        if quit {
+            break;
+        }
+    });
+
+    let read_all = stdin_rx.for_each(move |line| {
+        // Handle the data sent by the Editor thread
+        let message = match line {
+            Ok(line) => format!("Line: {}", line),
+            Err(ReadlineError::Interrupted) => format!("CTRL-C"),
+            Err(ReadlineError::Eof) => format!("CTRL-D"),
+            Err(err) => format!("Error: {:?}", err),
+        };
+
+        // Communicate back data to print to the user.
+        stdout_tx.send(message).ok();
+
+        Ok(())
+    });
+
+    tokio::run(read_all.map_err(|_| ()));
+}