Functional Programming for Fun and Profit!!

Presented at RubyConf Mini 2022

Transcript

1. @jenny-codes Functional programming for fun and profit!!
2. @jenny_codes https://github.com/readme/featured/functional-programming
3. @jenny_codes Source: https://youtu.be/ADqLBc1vFwI
4. @jenny_codes Source: https://giphy.com/gifs/emoji-idk-thinking-3o7buirYcmV5nSwIRW What is functional programming?
5. @jenny_codes Source: https://giphy.com/gifs/emoji-idk-thinking-3o7buirYcmV5nSwIRW What is functional programming? Should I care about it if I just want to write Ruby code?
6. Functional programming helps us write better Ruby code
7. @jenny_codes Jenny Shih / 施靜樺
8. @jenny_codes Jenny Shih / 施靜樺 🇹🇼 Taiwan -> 🇨🇦 Canada 💎 💧 https://codecharms.me
9. Programming paradigms A way to classify programming languages based on their features
10. @jenny_codes Programming paradigms • Object Oriented Programming (OO) • Functional Programming (FP)
11. Mental model
12. @jenny_codes Value Time Behavior A program
13. @jenny_codes
14. @jenny_codes Value Behavior
15. @jenny_codes
16. @jenny_codes Time
17. @jenny_codes Value Time Behavior A program State
18. @jenny_codes Object An OO program Value Behavior Time Time
19. @jenny_codes An OO program Object Value Behavior Object Value Behavior Object Value Behavior Time Time Time Time Time Time
20. @jenny_codes A FP program Value Time Behavior
21. @jenny_codes A FP program Value Time Behavior
22. Immutability
23. Immutability Don’t change a value once you initialize it.
24. @jenny_codes Immutability
25. @jenny_codes Immutability
26. @jenny_codes Immutability
27. @jenny_codes Immutability
28. @jenny_codes Source: https://giphy.com/gifs/emoji-idk-thinking-3o7buirYcmV5nSwIRW Why?
29. @jenny_codes Immutability: Why?? • Peace of mind
30. @jenny_codes Immutability: Why??
31. @jenny_codes Immutability: Why?? • Peace of mind
32. @jenny_codes Immutability: Why?? • Peace of mind • Eliminate shared state
33. @jenny_codes Immutability: Why?? • Peace of mind • Eliminate shared state
34. @jenny_codes Immutability: How???
35. @jenny_codes Immutability: How??? • Provide a good reason for every value mutation.
36. @jenny_codes Immutability: How??? • Provide a good reason for every value mutation. • Use tools
37. @jenny_codes
38. @jenny_codes https://dry-rb.org/
39. @jenny_codes Immutability: How??? • Provide a good reason for every value mutation. • Use tools • `dry-struct`: https://dry-rb.org/gems/dry-struct/main/
40. @jenny_codes Immutability: How??? • Provide a good reason for every value mutation. • Use tools • `dry-struct`: https://dry-rb.org/gems/dry-struct/main/ • `Data.de fi ne` in Ruby
41. @jenny_codes
42. @jenny_codes
43. @jenny_codes https://dev.to/baweaver/new-in-ruby-32-datade fi ne-2819
44. @jenny_codes Immutability: How??? • Provide a good reason for every value mutation. • Use tools • `dry-struct`: https://dry-rb.org/gems/dry-struct/main/ • `Data.de fi ne` in Ruby
45. @jenny_codes A FP program Value Time Behavior
46. @jenny_codes A FP program Value Time Behavior Immutable data
47. @jenny_codes A FP program Value Time Behavior Immutable data
48. Pure functions
49. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
50. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
51. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
52. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
53. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
54. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
55. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
56. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
57. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
58. @jenny_codes Source: https://giphy.com/gifs/emoji-idk-thinking-3o7buirYcmV5nSwIRW Why?
59. @jenny_codes “The problem with OO languages is they’ve got all this implicit environment that they carry around with them. You wanted a banana but what you got was a gorilla holding the banana and the entire jungle.” – Joe Armstrong, Creator of Erlang Pure functions: Why??
60. @jenny_codes “The problem with OO languages is they’ve got all this implicit environment that they carry around with them. You wanted a banana but what you got was a gorilla holding the banana and the entire jungle.” – Joe Armstrong, Creator of Erlang Pure functions: Why??
61. @jenny_codes Pure functions: Why?? No implicit environment!! Source: https://thenounproject.com/icon/forest-5299391/ Source: https://thenounproject.com/icon/monkey-298282/
62. @jenny_codes Pure functions: Why?? No implicit environment!! Source: https://thenounproject.com/icon/forest-5299391/ Source: https://thenounproject.com/icon/monkey-298282/
63. @jenny_codes Pure functions: Why?? No implicit environment!! 🤯
64. @jenny_codes Pure functions: Why?? No implicit environment!!
65. @jenny_codes Pure functions: Why?? No implicit environment!! 🤘
66. @jenny_codes Pure functions: Why?? No implicit environment!! 🤘🐛 🔪
67. @jenny_codes Pure functions: Why?? No implicit environment!! 🤘🐛 🔪 🧪
68. @jenny_codes Pure functions: Why?? No implicit environment!! 🤘🐛 🔪 🧪 ✅
69. @jenny_codes Pure functions: Why?? No implicit environment!! 🤘🐛 🔪 🧪 ✅ ✌
70. @jenny_codes Pure functions: Why?? No implicit environment!! 🤘🐛 🔪 🧪 ✅ ✌ Source: https://www.ktiv.com/2022/10/07/nobel-peace-prize-awarded-human-rights-advocates/
71. @jenny_codes Pure functions: How???
72. @jenny_codes Pure functions: How??? • Parameterization/Dependency Injections
73. @jenny_codes Pure functions: Parameterization
74. @jenny_codes Pure functions: Parameterization
75. @jenny_codes Pure functions: Parameterization
76. @jenny_codes Pure functions: Parameterization
77. @jenny_codes Pure functions: Parameterization
78. @jenny_codes Pure functions: Parameterization
79. @jenny_codes Pure functions: Parameterization
80. @jenny_codes Pure functions: Parameterization
81. @jenny_codes Pure functions: Parameterization
82. @jenny_codes Pure functions: Parameterization
83. @jenny_codes Pure functions: How??? • Parameterization/Dependency Injections • Transformation instead of mutation
84. @jenny_codes Pure functions: Transformation over Mutation
85. @jenny_codes Pure functions: Transformation over Mutation
86. @jenny_codes Pure functions: Transformation over Mutation
87. @jenny_codes 1. Only depends on its input argument 2. Does not mutate states (no side effects) A pure function
88. @jenny_codes A pure function 1. Only depends on its input argument ✅ 2. Does not mutate states (no side effects)
89. @jenny_codes A pure function 1. Only depends on its input argument ✅ 2. Does not mutate states ✅ (no side effects)
90. @jenny_codes A FP program Value Time Behavior Immutable data
91. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions
92. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions
93. Concurrency
94. @jenny_codes An OO program Object Value Behavior Object Value Behavior Object Value Behavior Time Time Time Time Time Time
95. @jenny_codes An OO program Object Value Behavior Object Value Behavior Object Value Behavior Time Time Time Time Time Time Global Interpreter Lock 🔐
96. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions Concurrency 💯
97. @jenny_codes Elixir’s concurrency model: Actors Actor / Process Actor / Process Actor / Process
98. @jenny_codes Elixir’s concurrency model: Actors Thread Thread Thread
99. @jenny_codes “It’s multi-core age today. Concurrency is very important. With Ractor, along with Async Fiber, Ruby will be a real concurrent language.” — Matz Ruby’s concurrency abstraction: Ractor https://www.ruby-lang.org/en/news/2020/12/25/ruby-3-0-0-released/
100. @jenny_codes Ractor Ractor Ractor ︴︴︴ ︴︴︴ ︴︴︴ Ruby’s concurrency abstraction: Ractor ︴︴︴= threads
101. @jenny_codes Ractor Ractor Ractor 🔐 🔐 🔐 ︴︴︴ ︴︴︴ ︴︴︴ 🔐 = Global Interpreter Lock Ruby’s concurrency abstraction: Ractor ︴︴︴= threads
102. @jenny_codes Ractor Ractor Ractor 🔐 🔐 🔐 ︴︴︴ ︴︴︴ ︴︴︴ 🔐 = Global Interpretation Lock Ruby’s concurrency abstraction: Ractor ︴︴︴= threads ❓
103. @jenny_codes
104. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions Concurrency
105. Recap
106. @jenny_codes We are defined not so much by what we can do, but what we don’t do.
107. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions Concurrency
108. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions Concurrency
109. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions Concurrency
110. @jenny_codes A FP program Value Time Behavior Immutable data Pure functions Concurrency
111. Functional programming helps us write better Ruby code
112. @jenny_codes Resources: Functional programming mental model • Jose Valim’s ElixirConf 2017 Keynote by Jose Valim • Are we there yet by Rich Hickey • The language of programming by Anjana Vakil • Value Object by Martin Fowler
113. @jenny_codes Resources: Functional programming architecture (That I didn’t get to talk about because I’d get too excited and run overtime) • Functional Architecture for the Practical Rubyist by Tim Riley • Functional web with Ruby by Luca Luigi • Boundaries by Gary Bernhardt • The Hanami Ruby framework • (Book) Domain Modelling Made Functional by Scott Wlaschin
114. @jenny_codes Resources: Ruby docs • https://ruby-doc.org/core-3.2.0_preview2/Ractor.html • https://scoutapm.com/blog/ruby-ractor • https://dev.to/baweaver/new-in-ruby-32-datade fi ne-2819 • https://github.com/ruby/ruby/pull/6353