added pass by value and fan pattern

concurrency/fan/main.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	randomNumbers := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
+	// generate the common channel with inputs
+	inputChan := generatePipeline(randomNumbers)
+
+	// Fan-out to 2 Go-routine
+	c1 := squareNumber(inputChan)
+	c2 := squareNumber(inputChan)
+
+	// Fan-in the resulting squared numbers
+	c := fanIn(c1, c2)
+	sum := 0
+
+	// Do the summation
+	for i := 0; i < len(randomNumbers); i++ {
+		sum += <-c
+	}
+	fmt.Printf("Total Sum of Squares: %d", sum)
+}
+
+func generatePipeline(numbers []int) <-chan int {
+	out := make(chan int)
+	go func() {
+		for _, n := range numbers {
+			out <- n
+		}
+		close(out)
+	}()
+	return out
+}
+
+func squareNumber(in <-chan int) <-chan int {
+	out := make(chan int)
+	go func() {
+		for n := range in {
+			out <- n * n
+		}
+		close(out)
+	}()
+	return out
+}
+
+func fanIn(input1, input2 <-chan int) <-chan int {
+	c := make(chan int)
+	go func() {
+		for {
+			select {
+			case s := <-input1:
+				c <- s
+			case s := <-input2:
+				c <- s
+			}
+		}
+	}()
+	return c
+}

concurrency/runner/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"errors"
+	"os"
+	"os/signal"
+	"time"
+)
+
+type Runner struct {
+	interrupt chan os.Signal
+	complete  chan error
+	timeout   <-chan time.Time
+	tasks     []func(int)
+}
+
+var ErrTimeout = errors.New("Received Timeout")
+var ErrInterrupt = errors.New("Received Interrupt")
+
+func New(d time.Duration) *Runner {
+	return &Runner{
+		interrupt: make(chan os.Signal, 1),
+		complete:  make(chan error),
+		timeout:   time.After(d),
+	}
+}
+
+func (r *Runner) Add(tasks ...func(int)) {
+	r.tasks = append(r.tasks, tasks...)
+}
+
+func (r *Runner) Start() error {
+	signal.Notify(r.interrupt, os.Interrupt)
+}

idiom/passbyvalue/main.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"github.com/davecgh/go-spew/spew"
+)
+
+type Person struct {
+	Name string
+	Age  int
+}
+
+func main() {
+
+	s := "TTTT"
+	ps := &s
+	spew.Dump("ORIGINAL PS", ps)
+	spew.Dump("ADDRESS OF PS", &ps)
+
+	pass(ps)
+	spew.Dump("The Value Of S", s)
+	p1 := &Person{"Jian", 23}
+	passStruct(p1)
+	spew.Dump("STRUCT AFTER PASSS STRUCT", p1)
+
+}
+
+func pass(ps *string) {
+	*ps = "ZZZZZZZZZZZZZZZZZ"
+	spew.Dump("PS IN PASS FUNCIONT", ps)
+	spew.Dump("ADDRESS OF PS IN PASS FUNCIONT", &ps)
+	ps = nil
+}
+
+func passStruct(p *Person) {
+	p.Name = "Steve"
+	p = nil
+}
+
+func passStruct2(p Person) {
+	p.Name = "Steve"
+}
+
+func passVAL(v string) {
+	v = ""
+}