Sugar-Free Ruby

Ruby has a lot of syntax to come to terms with. In an effort to reduce learning overhead we often restrict what we teach by avoiding serious coverage of objects in early lessons. Yet objects are what make Ruby great. Rather than sacrifice Object Oriented Mechanics, Sugar-free ruby uses a minimum of syntactic sugar to reinforce the message-passing objective semantics of Ruby until the pupil understands and then can assimilate new syntactic elements with greater ease. This talk explores the advantages and pitfalls of the technique as well as other ways to teach Ruby.

Transcript

1. Sugar-Free Ruby A Look at Object-First Teaching
2. Who is this guy? Steven! Ragnarök contact = { "GitHub" => "nuclearsandwich", "Freenode" => "nuclearsandwich", "Email" => "steven@nuclearsandwich.com", "WWW" => "www.nuclearsandwich.com", "Twitter" => "@nuclearsandwich" } ''That guy with all the opinions''
3. Teaching Programming
4. Why is teaching so damn hard?
5. Why is teaching so damn hard? • It's hard to remember learning to program
6. Why is teaching so damn hard? • It's hard to remember learning to program • It's hard to share knowledge instead of guard it
7. Why is teaching so damn hard? In short: it takes a lot of self reflection to teach well.
8. Teaching Programming It's getting better
9. Kids learn: • Game Builder • Scratch • Python • Hackety-Hack / Shoes
10. Programming is fun
11. • Workshops for Women • Kids Ruby • Workshops / Curriculum in other languages
12. Programming is hard… But only this hard
13. RailsBridge: Workshops for Women • Install all the things the night before • One full day • Focus on Ruby, Rails, or split based on experience
14. Teaching Ruby The challenge
15. Why do you want to learn Ruby?
16. Why do you want to learn Ruby? • I hate my job and hear programmers make bank
17. Why do you want to learn Ruby? • I hate my job and hear programmers make bank • I know how to program but not Ruby
18. Why do you want to learn Ruby? • I hate my job and hear programmers make bank • I know how to program but not Ruby • I'm curious about programming
19. Disclaimer This point onward: Open minds only
20. Disclaimer Haters, the doors are stage left
21. Teaching Ruby The (Good?) Old Fashioned Way
22. Numbers 5 + 5 #=> 10 9 / 2 #=> 4 9.0 / 2 #=> 4.5
23. Strings and Symbols 'Hello' #=> "Hello" :what? #=> :what? "Hello, " + "World!" #=> "Hello, World!"
24. Boolean Values true #=> true false #=> false 20 < 100 #=> true true and false #=> false true or false #=> true
25. Arrays and Hashes [ 1, 2, 3.0, "four" ] { :name => "Steven!", :age => 24, :species => "human" }
26. Variable Assignment my_name = "Steven!" my_age = 24
27. Variable Access # ten years from now my_age + 10 #=> 34 # I hashify myself { :name => my_name, :age => my_age } #=> {:name => "Steven!", # :age => 24}
28. Console Output puts my_name Steven! #=> nil puts my_age + 10 34 #=> nil
29. Conditionals if my_name == "Steven!" puts "Hello!" else puts "Who are you?" end Hello! #=> nil
30. Loops while my_age < 30 do puts "Enjoying my twenties" my_age = my_age + 1 end
31. Methods "foo".upcase #=> "FOO"
32. Teaching Ruby What's wrong with this picture?
33. What's wrong with this picture? Six whole concepts come before methods.
34. What's wrong with this picture? No mention whatsoever of classes.
35. What's wrong with this picture? Why do we cling to this?
36. Ruby is not a computer language.
37. Ruby is not a computer language. So why are we teaching it like one?
38. Teaching Objects Ruby is the computer
39. But Steven!, If we try to teach all of that and Objects, their heads will explode!
40. Everything is an Object 5 #=> 5 42.0 #=> 42.0 "Hello!" #=> "Hello!" [1, 2, 3] #=> [1, 2, 3]
41. They Receive Messages "six".send :upcase #=> "SIX" 5.send :+, 9 #=> 14 17.send :nil? #=> false
42. Objects Have (a) Class 5.send :class #=> Fixnum 4.0.send :class #=> Float ["he's", "crazy?"].send :class #=> Array
43. Teaching Objects The pen and the scribe
44. Instantiation pen = Object.new #=> #<Object:0x007ff1c491de90>
45. Method Definition def pen.to_s "A trusty pen" end #=> nil
46. Message Sending pen.send :to_s #=> A trusty pen
47. A Pinch of Sugar def pen.to_s "A trusty pen" end pen.to_s #=> A trusty pen
48. Errors Are Your Friends pen.write "Hi there" #=> NoMethodError: undefined # method `write' for # A trusty pen:Object
49. Use the Kernel, Luke def pen.write thing Kernel.puts thing end #=> nil
50. Write Anything! pen.write "Hi" Hi #=> nil pen.write pen A trusty pen #=> nil
51. Feature Request: Color pen.ink_color = "Blue" #=> NoMethodError: undefined # method `ink_color=' for # A trusty pen:Object def pen.ink_color= color @ink_color = color end #=> nil
52. Showing Our Colors def pen.to_s "A trusty #{@ink_color} pen" end pen.ink_color = "purple" #=> "purple" pen #=> "A trusty purple pen"
53. Implicit Receivers def pen.sparkly_write thing write "*;. #{thing} *;.*" end pen.sparkly_write pen *;. A trusty purple pen *;.*
54. Conditionals Revisited def pen.html_write thing write if @ink_color "<p style=\"color: \ #{@ink_color};\"> #{thing} </p>" else "<p>#{thing}</p>" end end
55. Teaching Ruby What have we introduced?
56. Time to get classy… Scribe = Class.new do def initialize pen @pen = pen @items = Array.new end def note item @items.<< item end # to be continued
57. …you blockhead # in the Scribe class body def write_everything @items.each do |item| @pen.write item end end end #=> Scribe
58. Hiring a new scribe mielot = Scribe.new pen #=> #<Scribe:0x007fe57b086228 # @pen=A trusty purple pen> mielot.note "Time: #{Time.now}" mielot.note "This demo is over" mielot.write_everything Time: 2012-09-14 11:43:05 -0700 This demo is over
59. Teaching Ruby with Objects
60. Teaching Objects with Ruby
61. Why is this better? The object metaphor provides a context for everything else we learn about Ruby
62. Why is this better? We don't bombard them with new concepts until just before their use
63. Why is this better? With a thorough understanding of semantics, new things (like syntactic sugar) are more readily digestible
64. Thanks! Behind the Scenes X E L A TEX/ Beamer Pygments / Minted