Ready and Go!

A simple golang go through based on official/google golang team member sharing.

Transcript

1. Ready and Go!! ferrari := "@ferrari_tw"
2. Please watch this first!! Meet golang core team members!! https://www.youtube.com/watch?v=sln-gJaURzk
3. C/C++ & [Ruby|Python] & nodejs Why Go? Statically type/Dynamic/Concurrent
4. History 2007/9 - Go kick-off 2009/11 - First release 2012/3/28 - Go version 1 2013/2 - Go 1.1 freeze
5. I even didn't hear this before...
6. I even didn't hear this before... http://go-lang.cat-v.org/organizations-using-go
7. Basic build compile packages and dependencies clean remove object files doc run godoc on package sources env print Go environment information fix run go tool fix on packages fmt run gofmt on package sources get download and install packages and dependencies install compile and install packages and dependencies list list packages run compile and run Go program test test packages tool run specified go tool version print Go version vet run go tool vet on packages http://golang.org/cmd/go/#hdr-Run_gofmt_on_package_sources
8. Newbie package main import "fmt" const Hello = 'hello' func swap(x, y string) (string, string) { return y, x } func main() { a, b := swap(Hello, "world") // := func only, or var fmt.Println(a, b) }
9. Newbie (loop) func main() { sum := 0 for i := 0; i < 10; i++ { \\for loop, no while sum += i } } for sum < 10 { sum += sum }
10. Newbie (control) // if else func pow(x, n, lim float64) float64 { if v := math.Pow(x, n); v < lim { return v } else { fmt.Printf("%g >= %g\n", v, lim) } }
11. Newbie (control) // switch, no break switch os := runtime.GOOS; os { case "darwin": fmt.Println("OS X") case "linux": fmt.Println("Linux") default: fmt.Println("%s", os) }
12. Newbie (control) // switch, no condition == if else switch { case t.Hour() < 12: fmt.Println("morning") case t.Hour() < 17: fmt.Println("afternoon") default: fmt.Println("Evening") }
13. Newbie (struct) type Info struct { name string age int }
14. Newbie (map) var m map[string]int m = make(map[string]int) m["test"] = 123 var m = map[string]int { "test": 123, "test1": 5566, } v, ok := m["test2"] fmt.Println("Value: %s, Present: %b", v, ok)
15. Newbie (slices) p := []int{2,3,4,55} i := 2 fmt.Printf("p[%d] == %d\n", i, p[i]) p[1:2] // 3 p[:3] // 2,3,4 p[:2] // 4,55 for i, v := range p { // for _, v := range p fmt.Println("p[%d] = %d", i, v) }
16. Newbie (function) func main() { plus := func(x, y float64) float64 { return x + y } plus(5, 5) } func adder() func(int) int { sum := 0 return func(x int) int { sum += x return sum } }
17. Newbie (method) // no classes, define method on struct type Vertex struct { X, Y float64 } func (v *Vertex) Abs() float64 { return math.Sqrt(v.X*v.X + v.Y*v.Y) } func main() { v := &Vert{3, 4} fmt.Println(v.Abs()) }
18. Newbie (interface) // interface, a set of methods type Abser interface { Abs() float64 } func main() { var a Abser f := Myfloat() a = f } type Myfloat float64 func (f Myfloat) Abs() float64 { }
19. Newbie (Concurrency) Based on Communicating Sequential Processes (CSP), first described in 1978 by C.A.R. Hoare. The Go analogue: goroutines connected by channels Goroutines are like threads, share memory but cheaper!
20. Newbie (Concurrency) // Goroutines, Channels func sum(a []int, c chan int) { sum := 0 for _, v := range a { sum += v } c <- sum } func main() { a := []int{2, 3, 8, 10, 3} c := make(chan int) go sum(a[len(a)/2:], c) }
21. Newbie (import) go get SOURCE go install SOURCE http://godoc.org/
22. Newbie (defer, panic, recover) A defer statement pushes a function call onto a list. The list of saved calls is executed after the surrounding function returns. Panic is a built-in function that stops the ordinary flow of control and begins panicking. Recover is a built-in function that regains control of a panicking goroutine.
23. packages archive bufio builtin byptes compress container crypto database debug encoding erores expvar flag fmt go hash html image index io log math mime net os path reflect regexp runtime sort strconv strings sync syscall testing text time unicode unsafe
24. http://golang.org/doc/ http://golang.org/doc/effective_go.html Still have lots of stuff..!!
25. Stop Talk! I Gotta Go https://gist.github.com/Ferrari/4736960
26. http://proppy-go-ae.appspot.com Go + App Engine All I Want Is Google!!
27. Reference http://tour.golang.org/ http://golang.org/doc/codewalk http://www.kunli.info/2012/03/03/golang-feeling/ https://www.youtube.com/watch?v=4iAiS-qv26Q https://developers.google. com/appengine/docs/go/gettingstarted/