Ruby Stdlib – Minsk.rb October 2012

1. Ruby Stdlib Sergey Nartimov Brainspec https://github.com/lest twitter: @just_lest
2. About me • Rails, Rubinius, Elixir contributor • Software engineer at Brainspec • Consulting, training, development Sergey Nartimov Brainspec https://github.com/lest twitter: @just_lest
3. Struct
4. Struct class Point < Struct.new(:x, :y) end
5. Struct class Point < Struct.new(:x, :y) end point = Point.new(4, 2)
6. Struct class Point < Struct.new(:x, :y) end point = Point.new(4, 2) point.x # => 4 point.y # => 2
7. Struct class Point < Struct.new(:x, :y) end point = Point.new(4, 2) point.x # => 4 point.y # => 2 point.z # NoMethodError
8. OStruct
9. OStruct require 'ostruct'
10. OStruct require 'ostruct' point = OStruct.new(x: 4, y: 2)
11. OStruct require 'ostruct' point = OStruct.new(x: 4, y: 2) point.x # => 4 point.y # => 2
12. OStruct require 'ostruct' point = OStruct.new(x: 4, y: 2) point.x # => 4 point.y # => 2 point.z # => nil
13. OStruct require 'ostruct' point = OStruct.new(x: 4, y: 2) point.x # => 4 point.y # => 2 point.z # => nil point.z = 0
14. Set
15. Set input = [1, -2, 2, 3]
16. Set input = [1, -2, 2, 3] results = [] input.each do |value| results << value.abs end
17. Set input = [1, -2, 2, 3] results = [] input.each do |value| results << value.abs end results # => [1, 2, 2, 3]
18. Set input = [1, -2, 2, 3] results = [] input.each do |value| results << value.abs end results.uniq # => [1, 2, 3]
19. Set input = [1, -2, 2, 3] results = [] input.each do |value| results << value.abs unless ... end results # => [1, 2, 3]
20. Set require 'set'
21. Set require 'set' input = [1, -2, 2, 3]
22. Set require 'set' input = [1, -2, 2, 3] results = Set.new input.each do |value| results << value.abs end
23. Set require 'set' input = [1, -2, 2, 3] results = Set.new input.each do |value| results << value.abs end results # => #<Set: {1, 2, 3}>
24. SortedSet require 'set' set = SortedSet.new set << 1 set << 3 set << 2
25. SortedSet require 'set' set = SortedSet.new set << 1 set << 3 set << 2 output = [] set.each do |value| output << value end output # => [1, 2, 3]
26. Shellwords
27. Shellwords pattern = 'belongs_to :user'
28. Shellwords pattern = 'belongs_to :user' escaped = Shellwords.escape(pattern) system("grep -r #{escaped} app/models")
29. Shellwords pattern = 'belongs_to :user' escaped = Shellwords.escape(pattern) system("grep -r #{escaped} app/models") escaped = pattern.shellescape system("grep -r #{escaped} app/models")
30. Shellwords argv = ['grep', '-r', 'belongs_to :user', 'app/models']
31. Shellwords argv = ['grep', '-r', 'belongs_to :user', 'app/models'] system(argv.map(&:shellescape).join(' '))
32. Shellwords argv = ['grep', '-r', 'belongs_to :user', 'app/models'] system(argv.map(&:shellescape).join(' '))
33. Shellwords argv = ['grep', '-r', 'belongs_to :user', 'app/models'] system(argv.map(&:shellescape).join(' ')) system(Shellwords.join(argv))
34. Shellwords argv = ['grep', '-r', 'belongs_to :user', 'app/models'] system(argv.map(&:shellescape).join(' ')) system(Shellwords.join(argv)) system(argv.shelljoin)
35. Shellwords cmd = 'grep -r "belongs_to :user" app/ models'
36. Shellwords cmd = 'grep -r "belongs_to :user" app/ models' Shellwords.split(cmd) # => ["grep", "-r", "belongs_to :user", "app/models"]
37. Shellwords cmd = 'grep -r "belongs_to :user" app/ models' Shellwords.split(cmd) # => ["grep", "-r", "belongs_to :user", "app/models"] cmd.shellsplit # => ["grep", "-r", "belongs_to :user", "app/models"]
38. SecureRandom
39. SecureRandom require 'securerandom'
40. SecureRandom require 'securerandom' SecureRandom.base64 # => "7lM0q9QF8oYvq20WSGOmOw=="
41. SecureRandom require 'securerandom' SecureRandom.base64 # => "7lM0q9QF8oYvq20WSGOmOw==" SecureRandom.hex # => "c0cff5ead6260fe58ebd4ddab83a3497"
42. SecureRandom require 'securerandom' SecureRandom.base64 # => "7lM0q9QF8oYvq20WSGOmOw==" SecureRandom.hex # => "c0cff5ead6260fe58ebd4ddab83a3497" SecureRandom.uuid # => "4b6ff327-cb9f-43e2-a067-342072b144bd"
43. Delegator
44. Delegator class Person < Struct.new(:name) end person = Person.new('John')
45. Delegator class Person < Struct.new(:name) end person = Person.new('John') redditor = Reddittor.new(person)
46. Delegator class Person < Struct.new(:name) end person = Person.new('John') redditor = Reddittor.new(person) redditor.name # => 'John'
47. Delegator class Person < Struct.new(:name) end person = Person.new('John') redditor = Reddittor.new(person) redditor.name # => 'John' redditor.submit_link # => 'Link by John'
48. Delegator require 'delegate'
49. Delegator class Redditor < Delegator def initialize(person) end end
50. Delegator class Redditor < Delegator def initialize(person) end def __setobj__(person) @person = person end def __getobj__ @person end end
51. Delegator class Redditor < Delegator def initialize(person) __setobj__(person) end def __setobj__(person) @person = person end def __getobj__ @person end end
52. Delegator class Redditor < Delegator def initialize(person) __setobj__(person) end def __setobj__(person) @person = person end def __getobj__ @person end def submit_link "Link by #{name}" end end
53. Delegator person = Person.new('John') redditor = Redditor.new(person) redditor.name # => 'John' redditor.submit_link # => 'Link by John'
54. tl;dr
55. Delegator class Redditor < SimpleDelegator def initialize(person) super(person) end def submit_link "Link by #{name}" end end
56. Delegator person = Person.new('John') redditor = Redditor.new(person) redditor.name # => 'John'
57. Delegator person = Person.new('John') redditor = Redditor.new(person) redditor.name # => 'John' redditor.methods.grep(/name/) # => [:name, :name=]
58. Delegator person = Person.new('John') redditor = Redditor.new(person) redditor.name # => 'John' redditor.methods.grep(/name/) # => [:name, :name=] Redditor.instance_methods.grep(/name/) # => []
59. Delegator class Redditor < DelegateClass(Person) def initialize(person) super(person) end def submit_link "Link by #{name}" end end
60. Delegator class Redditor < DelegateClass(Person) def initialize(person) super(person) end def submit_link "Link by #{name}" end end Redditor.instance_methods.grep(/name/) # => [:name, :name=]
61. Thanks! Sergey Nartimov Brainspec https://github.com/lest twitter: @just_lest