1 files changed, 37 insertions, 0 deletions
diff --git a/third_party/rust/warp/examples/futures.rs b/third_party/rust/warp/examples/futures.rs
new file mode 100644
index 0000000000..43bf2f6efa
--- /dev/null
+++ b/third_party/rust/warp/examples/futures.rs
@@ -0,0 +1,37 @@
+#![deny(warnings)]
+
+use std::convert::Infallible;
+use std::str::FromStr;
+use std::time::Duration;
+use warp::Filter;
+
+#[tokio::main]
+async fn main() {
+    // Match `/:Seconds`...
+    let routes = warp::path::param()
+        // and_then create a `Future` that will simply wait N seconds...
+        .and_then(sleepy);
+
+    warp::serve(routes).run(([127, 0, 0, 1], 3030)).await;
+}
+
+async fn sleepy(Seconds(seconds): Seconds) -> Result<impl warp::Reply, Infallible> {
+    tokio::time::sleep(Duration::from_secs(seconds)).await;
+    Ok(format!("I waited {} seconds!", seconds))
+}
+
+/// A newtype to enforce our maximum allowed seconds.
+struct Seconds(u64);
+
+impl FromStr for Seconds {
+    type Err = ();
+    fn from_str(src: &str) -> Result<Self, Self::Err> {
+        src.parse::<u64>().map_err(|_| ()).and_then(|num| {
+            if num <= 5 {
+                Ok(Seconds(num))
+            } else {
+                Err(())
+            }
+        })
+    }
+}