Building Better Packages

What does it mean to write good Go code? How can we build packages that feel like they belong in the standard library? In this talk we will analyze the characteristics of well designed interfaces and how better packages make for simpler programs.)

Transcript

1. BUILDING BETTER PACKAGES
3. WE ALL HAVE WRITTEN SHITTY CODE
4. Code Quality Design Effort
7. IMPLEMENTATION
8. IMPLEMENTATION INTERFACE
9. SIMPLICITY FLEXIBILITY CONTINUITY
10. SIMPLICITY FLEXIBILITY CONTINUITY
11. SIMPLICITY FLEXIBILITY CONTINUITY
12. SIMPLICITY FLEXIBILITY CONTINUITY
13. SIMPLICITY
14. SIMPLICITY IS PREREQUISITE FOR RELIABILITY EDSGER DIJKSTRA
15. SIMPLE MADE EASY RICH HICKEY
16. SINGULARITY
17. ONE ROLE
18. ONE TASK
19. ONE CONCEPT
20. ONE DIMENSION
21. DISCOVERY
23. LETTER OPENERS AND NOT SWISS ARMY KNIFES
24. WHAT DOES IT MEAN?
25. WHAT DOES IT ACCOMPLISH?
26. WHAT DOES IT OFFER?
27. EXAMPLE: negroni
28. EXAMPLE: Run(addr string) ServeHTTP(rw http.ResponseWriter, r *http.Request) Use(h Handler) UseHandler(h http.Handler)
29. FLEXIBILITY
30. COMPLIMENTS GROWTH
31. INTERFACES
32. INTERFACES: type Writer interface { Write(p []byte) (n int, err error) }
33. INTERFACES: type Writer interface { Write(p []byte) (n int, err error) }
34. INTERFACES: type FileSystem interface { Open(name string) (File, error) }
35. INTERFACES: type FileSystem interface { Open(name string) (File, error) }
36. ALWAYS USE INTERFACES
37. ALWAYS USE INTERFACES
38. MOSTLY USE INTERFACES
39. INTERFACES COMMUNICATE CONCRETENESS
40. INTERFACES COMMUNICATE STABILITY
41. INTERFACES COMMUNICATE COMMITMENT
42. RETURN VALUE?
43. RETURN VALUE? STRUCT
44. ARGUMENT VALUE?
45. ARGUMENT VALUE? INTERFACE
46. EXAMPLE: pkg/bufio
47. EXAMPLE: NewWriter(w io.Writer) *Writer
48. EXAMPLE: NewWriter(w io.Writer) *Writer
49. EXAMPLE: NewWriter(w io.Writer) *Writer
50. DISCOVERING INTERFACES
52. OS.FILE
53. IO.WRITER VS OS.FILE
54. CONTINUITY
57. FICTIONAL CONTINUITY
58. THE CONSISTENCY OF THE CHARACTERISTICS OF PERSONS, PLOT, OBJECTS, PLACES AND EVENTS SEEN BY THE READER OR VIEWER
59. THE CONSISTENCY OF THE CHARACTERISTICS OF PERSONS, PLOT, OBJECTS, PLACES AND EVENTS SEEN BY THE READER OR VIEWER
60. HOW?
61. WRITE CODE LIKE… A MORON
62. WRITE CODE LIKE… IT ALREADY EXISTS
63. WRITE CODE LIKE… IT’S A PART OF THE GO STDLIB
64. EXAMPLE: gorilla/mux
65. EXAMPLE: func main() { r := mux.NewRouter() r.HandleFunc("/", Home) r.HandleFunc("/products", Products) http.Handle("/", r) }
66. EXAMPLE: func main() { r := mux.NewRouter() r.HandleFunc("/", Home) r.HandleFunc("/products", Products) http.Handle("/", r) }
67. NEED EXAMPLES?
68. DIG INTO THE STDLIB
69. EXTEND IT!
70. WE MADE IT
71. SIMPLICITY FLEXIBILITY CONTINUITY
72. - A WORLD THAT SEEMS TO HAVE BEEN GOING ON BEFORE WE STUMBLED INTO IT BUT WHICH, ONCE FOUND BY THE RIGHT READER, BECOMES INDISPENSABLE TO HIM. CS LEWIS
73. @CODEGANGSTA