Give Elm a Chance!

Transcript

1. 
 Give Elm a Chance! Joel Clermont
 @jclermont
2. Hello audience
3. Goals • Elm language tour
4. What to expect Elm language tour
5. What to expect What is Elm?
6. What to expect Why Elm at a PHP group?
7. What to expect What makes Elm useful and interesting? • Code that doesn’t crash • A powerful type system • Ecosystem: quality over quantity • Care-free refactoring • Amazing QA / debug experience
8. What is Elm?
9. What is Elm? Elm is a language that compiles to JS
10. What is Elm? Elm (currently) targets the browser
11. What is Elm? Elm does not replace PHP, C#, Elixir, etc
12. What is Elm? Elm does not (yet) replace JavaScript
13. Questions?
14. Why Elm at a PHP group?
15. Why Elm at a PHP group? Front-end vs. back-end
16. Why Elm at a PHP group? User interfaces get complex quickly
21. Questions?
22. The Elm Architecture
23. Language + Framework
24. Model
25. Update
26. View
28. No side effects
29. Questions?
30. No runtime exceptions
31. No runtime exceptions • Hooray, no bugs! Not quite.
32. No runtime exceptions • Hooray, no bugs! Not quite. • Runtime exceptions are a common class of bugs
33. No runtime exceptions • Hooray, no bugs! Not quite. • Runtime exceptions are a common class of bugs • “undefined is not a function”
34. No Red Ink’s testimonial Since we began using Elm in 2015, our production Elm code has yet to cause a single runtime exception. Our error logs show plenty of crashes from our legacy JavaScript code, but none from our Elm code. We've also found our Elm-powered front-end substantially easier to scale than our previous React code base.
35. Spot the error
36. Pattern matching
37. Error handling in types
38. Questions?
39. The power of the type system
40. The power of the type system • PHP’s type system is getting better, but still basic
41. The power of the type system • PHP’s type system is getting better, but still basic • C# and Java? Better yet, but not very expressive
42. The power of the type system • PHP’s type system is getting better, but still basic • C# and Java? Better yet, but not very expressive • ML type system
43. Algebraic data types
44. Data modeling!! https://youtu.be/IcgmSRJHu_8
45. Questions?
46. Ecosystem
47. Elm ecosystem • Package manager enforces semantic versioning • API design is extremely thoughtful • Awesome tooling!
48. Elm ecosystem • Package manager enforces semantic versioning
49. Elm ecosystem • Package manager enforces semantic versioning • API design is extremely thoughtful
50. Elm ecosystem • Package manager enforces semantic versioning • API design is extremely thoughtful • Awesome tooling!
51. Compiler
52. Editors
53. Editors
54. Editors
55. Editors
56. Editors
57. Debugger http://elm-lang.org/assets/blog/0.18/todomvc.html
58. Ellie https://ellie-app.com/kLKCgY6sK9/0
59. Questions?
60. My final sales pitch • Welcoming community • Lots of effort to making concepts accessible • Easy to use it gradually • Will make you a better JavaScript developer
61. Next steps • http://elm-lang.org (live demos, debugger, REPL) • https://pragmaticstudio.com/elm • https://guide.elm-lang.org/ • https://frontendmasters.com/courses/elm/ • https://www.dailydrip.com/topics/elm • @elmlang @czaplic @rtfeldman @jclermont
62. Questions? @jclermont
63. Thank you! @jclermont