anonymous closure,lazyevaluation and future with go lang

Author: s1thu

go_routine/anonymous_closure/main.go

@@ -0,0 +1,19 @@
+package main
+
+import "fmt"
+
+func prod(c chan func()) {
+	f := <-c
+	f()
+	c <- nil
+}
+
+func main() {
+	c := make(chan func())
+	go prod(c)
+	x := 0
+	c <- func() { // puts a closure in channel c
+		x++
+	}
+	fmt.Println(x)
+}

go_routine/future(async_value)/future.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func FutureValue() <-chan int {
+	ch := make(chan int)
+	go func() {
+		fmt.Println("Computing in background...")
+		time.Sleep(2 * time.Second)
+		ch <- 42 // Send result after delay
+	}()
+	return ch
+}
+
+func main() {
+	future := FutureValue()
+	fmt.Println("Future started, doing other work...")
+
+	// Do something else here...
+
+	result := <-future // Wait for future value
+	fmt.Println("Got future result:", result)
+}

go_routine/lazy_evaluation/lazy_eva.go

@@ -0,0 +1,19 @@
+package main
+
+import "fmt"
+
+// LazySum returns a function that calculates sum only when called
+func LazySum(a, b int) func() int {
+	return func() int {
+		fmt.Println("Evaluating sum now...")
+		return a + b
+	}
+}
+
+func main() {
+	sum := LazySum(5, 7) // Not yet evaluated
+	fmt.Println("Sum function created, not evaluated.")
+
+	result := sum() // Evaluated here
+	fmt.Println("Result:", result)
+}