llgo/x/io: Promise: Async/Await

x/io/_demo/asyncdemo/async.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/goplus/llgo/x/io"
+)
+
+var GetUser = io.Async[any](func(string) any {
+	panic("todo: GetUser")
+})
+
+var GetScore = io.Async[float64](func() float64 {
+	panic("todo: GetScore")
+})
+
+var DoUpdate = io.Async[io.Void](func(op string) io.Void {
+	panic("todo: DoUpdate")
+})
+
+func main() {
+	user, err := GetUser("123").Await()
+	fmt.Println(user, err)
+
+	user, err = io.Race(GetUser("123"), GetUser("456"), GetUser("789")).Await()
+	fmt.Println(user, err)
+
+	user, score, _, err := io.Await3[any, float64, io.Void](GetUser("123"), GetScore(), DoUpdate("update sth."))
+	fmt.Println(user, score, err)
+
+	select {
+	case user := <-GetUser("123"):
+		fmt.Println("user:", user)
+	case score := <-GetScore():
+		fmt.Println("score:", score)
+	case <-io.Timeout(5 * time.Second):
+		fmt.Println("timeout")
+	}
+}