From 418f3beebbe9ac34e46ac88aae63180500df5d0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?O=C4=9Fuzhan=20Kazak?= <oguzhankazakk@gmail.com>
Date: Sun, 30 Apr 2023 14:09:10 +0300
Subject: [PATCH] Added "future_promise.md" file with an explanation of the
 future/promise pattern as reference.

---
 messaging/future_promise.md | 50 +++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 messaging/future_promise.md

diff --git a/messaging/future_promise.md b/messaging/future_promise.md
new file mode 100644
index 0000000..767f8aa
--- /dev/null
+++ b/messaging/future_promise.md
@@ -0,0 +1,50 @@
+# Future & Promise Pattern
+
+    Future pattern (also called Promise pattern) is a design pattern used in concurrent and asynchronous programming, which allows clients to start a potentially long-running operation and obtain its result in a non-blocking way by returning a placeholder object (a future or a promise).
+
+    When the operation completes, the result is set on the future/promise object, which can then be obtained by the client code through a blocking or non-blocking method call.
+
+### Types
+
+```go
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+type FutureInt struct {
+	ch chan int
+}
+```
+
+### Implementation
+
+```go
+func (f *FutureInt) Get() int {
+	return <-f.ch
+}
+
+func NewFutureInt() *FutureInt {
+	return &FutureInt{
+		ch: make(chan int),
+	}
+}
+
+func add(a, b int) *FutureInt {
+	f := NewFutureInt()
+	go func() {
+		time.Sleep(3 * time.Second) // Simulate long running task
+		f.ch <- a + b
+	}()
+	return f
+}
+
+func main() {
+	fmt.Println("Starting task...")
+	f := add(2, 3)
+	fmt.Println("Task started...")
+	fmt.Printf("Result: %d\n", f.Get())
+}
+```