Give Elm a Chance! (that conference)

Transcript

1. 
 Give Elm a Chance! Joel Clermont
 @jclermont
2. Hello audience
3. Goal
 You leave here wanting to
 play with Elm for an afternoon
4. What to expect Elm language tour
5. What to expect What is Elm?
6. What to expect Why bother with Elm instead of Javascript?
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. The Elm Architecture
14. Language + Framework
15. Model
16. Update
17. View
19. No side effects
20. Questions?
21. Why bother with Elm instead of Javascript?
23. Why bother with Elm instead of Javascript? User interfaces get complex quickly
28. What makes Elm useful and interesting?
29. No runtime exceptions
30. No runtime exceptions • Hooray, no bugs! Not quite.
31. No runtime exceptions • Hooray, no bugs! Not quite. • Runtime exceptions are a common class of bugs
32. No runtime exceptions • Hooray, no bugs! Not quite. • Runtime exceptions are a common class of bugs • “undefined is not a function”
33. 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.
34. Spot the error
35. Pattern matching
36. Error handling in types
37. Algebraic data types
38. 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
39. Data modeling!! https://youtu.be/IcgmSRJHu_8
40. Refactoring • refactoring can be scary on larger projects, even with tests • First few times, I thought it couldn’t possibly be that easy in Elm • Move things around, get everything to compile, done
41. Questions?
42. Ecosystem
43. Elm ecosystem • Package manager enforces semantic versioning
44. Elm ecosystem • Package manager enforces semantic versioning • API design is extremely thoughtful
45. Elm ecosystem • Package manager enforces semantic versioning • API design is extremely thoughtful • Awesome tooling!
46. Compiler
47. Editors
48. Editors
49. Editors
50. Editors
51. Editors
52. Debugger http://elm-lang.org/assets/blog/0.18/todomvc.html
53. Ellie https://ellie-app.com/kLKCgY6sK9/0
54. Bonus Elm Goodies Elm Search Elm CSS Style Elements
55. Questions?
56. My story with Elm
57. 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 • Developing with Elm is fun!
58. Closing survey
59. Next steps • http://elm-lang.org • https://guide.elm-lang.org/ • https://pragmaticstudio.com/elm • https://frontendmasters.com/courses/elm/ • https://www.dailydrip.com/topics/elm • @elmlang @czaplic @rtfeldman @jclermont
60. I want to hear from you 
 @jclermont
61. Questions? @jclermont
62. Thank you! @jclermont