Add async/await example

Author: agentcooper

examples/async-await/async-await.kt

@@ -0,0 +1,19 @@
+import kotlinx.coroutines.*
+import kotlin.system.*
+
+suspend fun sumParallel(): Int = coroutineScope {
+    val a = async { f(100, 1) }
+    val b = async { f(200, 5) }
+    a.await() + b.await()
+}
+
+suspend fun f(v: Int, s: Int): Int {
+    println("Fetching $v...")
+    delay(s * 1000L)
+    return v
+}
+
+fun main() = runBlocking {
+    val result = sumParallel()
+    println(result)
+}

examples/async-await/async-await.rs

@@ -0,0 +1,21 @@
+use tokio::time::{sleep, Duration};
+
+async fn sum_parallel() -> u64 {
+    let a_future = f(100, 1);
+    let b_future = f(200, 5);
+    let (a, b) = futures::join!(a_future, b_future);
+    return a + b
+}
+
+async fn f(v: u64, s: u64) -> u64 {
+    println!("Fetching {v}...");
+    // delay
+    sleep(Duration::from_secs(s)).await;
+    return v
+}
+
+#[tokio::main]
+async fn main() {
+    let result = sum_parallel().await;
+    print!("{}", result)
+}

examples/async-await/async-await.swift

@@ -0,0 +1,23 @@
+import Foundation
+
+func sumParallel() async -> Int {
+  async let a = f(100, 1)
+  async let b = f(200, 5)
+  return await a + b
+}
+
+func f(_ v: Int, _ s: Int) async -> Int
+{
+  print("Fetching \(v)...")
+  // delay
+  let ns = UInt64(s * 1_000_000_000)
+  try! await Task.sleep(nanoseconds: ns)
+  return v
+}
+
+@main struct Main {
+  static func main() async {
+    let result = await sumParallel()
+    print(result)
+  }
+}

examples/async-await/async-await.ts

@@ -0,0 +1,20 @@
+async function sumParallel() {
+  const aPromise = f(100, 1);
+  const bPromise = f(200, 5);
+  const [a, b] = await Promise.all([
+    aPromise,
+    bPromise,
+  ]);
+  return a + b;
+}
+
+async function f(v: number, s: number) {
+  console.log(`Fetching ${v}...`);
+  // delay
+  await new Promise((resolve) => {
+    setTimeout(resolve, s * 1000);
+  });
+  return v;
+}
+
+sumParallel().then(console.log);

package-lock.json

@@ -42,8 +42,8 @@ export const examples: Example[] = [
         __dirname +
           "/../examples/protocols-interfaces-traits/stack.rs",
         "utf-8"
-      )
-    }
+      ),
+    },
   },
   {
     key: "collections",
@@ -68,8 +68,8 @@ export const examples: Example[] = [
         __dirname +
           "/../examples/collections/collections.rs",
         "utf-8"
-      )
-    }
+      ),
+    },
   },
   {
     key: "higher-order-functions",
@@ -94,8 +94,8 @@ export const examples: Example[] = [
         __dirname +
           "/../examples/higher-order-functions/map.rs",
         "utf-8"
-      )
-    }
+      ),
+    },
   },
   {
     key: "algebraic-data-types",
@@ -120,7 +120,33 @@ export const examples: Example[] = [
         __dirname +
           "/../examples/algebraic-data-types/algebraic-data-types.rs",
         "utf-8"
-      )
-    }
-  }
+      ),
+    },
+  },
+  {
+    key: "async-await",
+    title: "Concurrency with async/await",
+    code: {
+      swift: readFileSync(
+        __dirname +
+          "/../examples/async-await/async-await.swift",
+        "utf-8"
+      ),
+      kotlin: readFileSync(
+        __dirname +
+          "/../examples/async-await/async-await.kt",
+        "utf-8"
+      ),
+      typescript: readFileSync(
+        __dirname +
+          "/../examples/async-await/async-await.ts",
+        "utf-8"
+      ),
+      rust: readFileSync(
+        __dirname +
+          "/../examples/async-await/async-await.rs",
+        "utf-8"
+      ),
+    },
+  },
 ];