The Functional Discipline

Slides of my talk at PartialConf 2017

Transcript

1. ! " The Functional Discipline Pedro Costa @pfac @iampfac
3. Meet John
4. Meet John
5. Meet John
6. Meet John $ 100
8. An over-engineer
9. € 1.0 for
 SOMEONE
10. New ideas
11. New ideas
12. New ideas
13. New ideas
14. New ideas
15. A functional way 1 2
16. 1 class GenerateBillText 2 attr_accessor :currency, :value 3 4 def initialize(currency:, value:) 5 @currency = currency 6 @value = value 7 end 8 9 def call 10 # ... generate image through ImageMagick ... 11 end 12 13 private 14 15 # ... any auxiliar method .. 16 end 17 18 GenerateBillText.new(currency: :eur, value: 1)
17. 1 class StepChain 2 attr_accessor :klasses 3 4 def initialize(*klasses) 5 @klasses = klasses 6 end 7 8 def call(initial) 9 klasses.reduce(initial) do |current, klass| 10 klass.new(current).call 11 end 12 end 13 end 14 15 StepChain. 16 new(GenerateBillText, ...). 17 call(currency: :eur, value: 1)
18. 1 class BillTextImage 2 attr_reader :path 3 4 def initialize(path:) 5 @path = path 6 end 7 end 8 9 BillTextImage.new(path: "~/tmp/bill_text.png")
26. ?
29. ?
32. OMG
35. HELP
36. – Cambridge Dictionary
 http://dictionary.cambridge.org/dictionary/english/discipline “the ability to control yourself (…), even in difficult situations.”
37. – Cambridge Dictionary
 http://dictionary.cambridge.org/dictionary/english/discipline “the ability to control yourself (…), even in difficult situations.”
38. Discipline is hard
39. Discipline is optional • You can reinvent the wheel, every time • You can be inconsistent • You can break boundaries • You just should not.
40. Who’s disciplined?
42. –Daniel Kahneman, “Thinking, Fast and Slow” “System 1 operates automatically and quickly, with little or no effort and no sense of voluntary control.”
43. –Daniel Kahneman, “Thinking, Fast and Slow” “System 2 allocates a!ention to the effortful mental activities that demand it, (…). The operations (…) are often associated with (…) agency, choice and concentration.”
44. Habits?
46. –Admiral William H. McRaven
 “University of Texas at Austin 2014 Commencement Address” https://www.youtube.com/watch?v=pxBQLFLei70 “If you can’t do the little things right, you will never do the big things right.”
55. Explore
57. But take caution
60. Don’t go too far
61. In the end
62. All you need is Discipline
63. Thank you
64. ! " The Functional Discipline Pedro “John” Costa @pfac @iampfac Questions?