Golang for Rubyists

Transcript

1. GOLANG FOR RUBYISTS RUBY WINE, APR 13 2019
2. ! RUBY SUX — GOLANG RULEZ!!!11 DISCLAIMER
3. ! RUBY SUX — GOLANG RULEZ!!!11 DISCLAIMER
4. whoami Nihad Abbasov github.com/narkoz nihad@42na.in
5. Agenda Introduction 01 Why Golang Comparing syntax and features Additional resources 02 03 04
7. Go is a modern, general purpose language.
8. Created in 2009 SECTION ONE
9. by Google for Google SECTION ONE
10. Go’s Creators • Ken Thompson (B, C, Unix, UTF-8) • Rob Pike (Unix, UTF-8) • Robert Griesmer (V8, HotSpot, JVM)
11. Go Today
12. Rewrite from Java to Go https://twitter.com/rob_pike/status/878412416127606784
13. Why Golang? SECTION TWO
14. “Go at Google: Language Design in the Service of Software Engineering” https://talks.golang.org/2012/splash.article SECTION TWO
15. Key points • must work at scale • must be familiar, roughly C-like • must be modern
16. Enter Go + Fast: fast compilation like interpreted language + Safe: strongly and statically typed and garbage collected + Easy: concise, easy to read + Modern: built in support for multi-core networked distributed applications
17. Popular areas where Go is used https://blog.golang.org/survey2018-results
18. Software written in Go https://blog.golang.org/survey2018-results
19. Getting started SECTION THREE
20. PROJECT LAYOUT https://golang.org/doc/code.html#Workspaces
21. HELLO WORLD package main import "fmt" func main() { fmt.Println("Hello, World!") }
22. RUNNING THE CODE go build hello-world.go ./hello-world
23. RUNNING THE CODE go run hello-world.go
24. Basic syntax SECTION THREE
25. Keywords https://golang.org/ref/spec#Keywords The following keywords are reserved and may not be used as identifiers.
26. Data types SECTION THREE
27. Data Types • Boolean types: true, false • Numeric types: integers, floats • String types • Derived types: pointers, arrays, structs, functions, slices, interfaces, maps, channels
28. Variables SECTION THREE
29. VARIABLES var x float64 x = 20.0 // same as above var x float64 = 20.0 foo := 42 var a, b, c = 3, 4, "foo" Static Declaration Dynamic Declaration Mixed Declaration
30. Conditionals SECTION THREE
31. CONDITIONALS if 7%2 == 0 { fmt.Println("7 is even") } else { fmt.Println("7 is odd") } if/else if 8%4 == 0 { fmt.Println("8 is divisible by 4") } if statement without an else
32. CONDITIONALS t := time.Now() switch { case t.Hour() < 12: fmt.Println("It’s before noon") default: fmt.Println("It’s after noon") } switch
33. Loops SECTION THREE
34. { LOOPS for for loop until while
35. LOOPS i := 1 for i <= 3 { fmt.Println(i) i = i + 1 } single condition for i := 0, i < 3; i++ { fmt.Println(i) } initial/condition/after
36. LOOPS for { fmt.Println("loop") break } for without a condition
37. Slices SECTION THREE
38. SLICES s := make([]string, 3) s[0] = "a" s[1] = "b" s[2] = "c" s = append(s, "d", "e")
39. Maps SECTION THREE
40. MAPS m := map[string]int{ "foo": 1, "bar": 2 } fmt.Println(m["foo"])
41. Functions SECTION THREE
42. FUNCTIONS func FunctionName([parameter_name type]) [return_types] { // body of the function } func plus(a int, b int) int { return a + b } sum := plus(1, 2)
43. FUNCTIONS func vals() (int, int) { return 3, 7 }
44. Exceptions SECTION THREE
45. EXCEPTIONS result, err:= Sqrt(-1) if err != nil { fmt.Println(err) }
46. Concurrency SECTION THREE
47. Concurrency != Parallelism SECTION THREE https://blog.golang.org/concurrency-is-not-parallelism
48. Concurrency is the composition of independently executed processes, while parallelism, is the simultaneous execution. Rob Pike
49. GOROUTINES func f(n int) { for i := 0; i < 10; i++ { fmt.Println(n, ":", i) } } func main() { go f(0) var input string fmt.Scanln(&input) }
50. CHANNELS func main() { messages := make(chan string) go func() { messages <- "ping" }() msg := <-messages fmt.Println(msg) }
51. Is Go object oriented? SECTION THREE
52. STRUCTS type Person struct { name string age int } p := Person{"John", 20} fmt.Println(p.name)
53. INTERFACES type Animal interface { Speak() string } type Cat struct { } func (c Cat) Speak() string { return "Meow!" }
54. Resources SECTION FOUR
55. RESOURCES The Go Programming Language by Alan Donovan Brian Kernighan
56. RESOURCES List of Golang books https://github.com/dariubs/GoBooks
57. RESOURCES A curated list of awesome Go frameworks, libraries and software https://github.com/avelino/awesome-go https://awesome-go.com/
58. RESOURCES Go Playground https://play.golang.org/ Go Tour https://tour.golang.org/
59. RESOURCES A weekly newsletter about the Go programming language https://golangweekly.com/
60. RESOURCES “Goby is an object-oriented interpreter language deeply inspired by Ruby as well as its core implementation by 100% pure Go” https://github.com/goby-lang/goby
61. Thanks! THE END