Writing your own Programming Language to Understand Ruby better

by Jose Valim

Transcript

1. José Valim @josevalim blog.plataformatec.com Writing your own Programming Language to Understand Ruby better Friday, September 16, 2011
2. blog twitter ID José Valim @josevalim blog.plataformatec.com Writing your own Programming Language to Understand Ruby better Friday, September 16, 2011
3. Elixir Simple Object Orientation and charming syntax on top of Erlang VM Friday, September 16, 2011
4. Erlang VM + Concurrent Processes + Message Based + Hot Code Swapping + Runs with low memory Friday, September 16, 2011
5. Erlang Language + Small and quick to learn + Functional programming - Syntax gets too much in your way - No object orientation Friday, September 16, 2011
6. Elixir Simple Object Orientation and charming syntax on top of Erlang VM Friday, September 16, 2011
7. <3 Ruby <3 Friday, September 16, 2011
8. Friday, September 16, 2011
9. @tenderl—ve Friday, September 16, 2011
10. * Things I learned about Ruby * What if? Friday, September 16, 2011
11. Things I learned about Ruby Friday, September 16, 2011
12. The Syntax Friday, September 16, 2011
13. puts “hi” Friday, September 16, 2011
14. puts “hi” Lexer Friday, September 16, 2011
15. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] Friday, September 16, 2011
16. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] Parser Friday, September 16, 2011
17. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] [:call, “puts”,[ [:string, “hi”] ]] Parser Friday, September 16, 2011
18. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] [:call, “puts”,[ [:string, “hi”] ]] Parser Semantic Analysis Friday, September 16, 2011
19. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] [:call, “puts”,[ [:string, “hi”] ]] Parser Semantic Analysis [:call, “puts”,[ [:string, “hi”] ]] Friday, September 16, 2011
20. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] [:call, “puts”,[ [:string, “hi”] ]] Parser Semantic Analysis [:call, “puts”,[ [:string, “hi”] ]] Native / Bytecode Friday, September 16, 2011
21. puts “hi” Lexer [:identifier, “puts”], [:string, “hi”] [:call, “puts”,[ [:string, “hi”] ]] Parser Semantic Analysis [:call, “puts”,[ [:string, “hi”] ]] Native / Bytecode Friday, September 16, 2011
22. Flexible Grammar Friday, September 16, 2011
23. def foo 1 end foo #=> 1 self.foo #=> 1 Friday, September 16, 2011
24. def foo 1 end foo #=> 1 self.foo #=> 1 foo = 2 foo #=> 2 self.foo #=> 1 Friday, September 16, 2011
25. foo Friday, September 16, 2011
26. foo Lexer Friday, September 16, 2011
27. foo Lexer [:identifier, “foo”] Friday, September 16, 2011
28. foo Lexer [:identifier, “foo”] Parser Friday, September 16, 2011
29. foo Lexer [:identifier, “foo”] [:identifier, “foo”] Parser Friday, September 16, 2011
30. foo Lexer [:identifier, “foo”] [:identifier, “foo”] Parser Semantic Analysis Friday, September 16, 2011
31. foo Lexer [:identifier, “foo”] [:identifier, “foo”] Parser Semantic Analysis ? Friday, September 16, 2011
32. foo Lexer [:identifier, “foo”] [:identifier, “foo”] Parser Semantic Analysis Native / Bytecode ? Friday, September 16, 2011
33. def bar foo = 1 foo end Friday, September 16, 2011
34. def bar foo = 1 foo end [:method,:bar,[ [:assign, "foo", [:integer,1]], [:identifier,"foo"] ]] lexer + parser Friday, September 16, 2011
35. def bar foo = 1 foo end [:method,:bar,[ [:assign, "foo", [:integer,1]], [:identifier,"foo"] ]] lexer + parser [:method,:bar,[ [:assign, "foo", [:integer,1]], [:var,"foo"] ]] semantic analysis Friday, September 16, 2011
36. Friday, September 16, 2011
37. def bar(arg) arg.class end bar /foo/m Friday, September 16, 2011
38. def bar(arg) arg.class end bar /foo/m bar, foo, m = 0, 1, 2 bar /foo/m Friday, September 16, 2011
39. Friday, September 16, 2011
40. Friday, September 16, 2011
41. def show @user = User.find(self.params[:id]) if @user.name =~ %r/^Ph\.D/i self.render :action => "show" else self.flash[:notice] = "Ph.D required" self.redirect_to "/" end end Friday, September 16, 2011
42. def show @user = User.find(params[:id]) if @user.name =~ /^Ph\.D/i render :action => "show" else flash[:notice] = "Ph.D required" redirect_to "/" end end Friday, September 16, 2011
43. Trivia Friday, September 16, 2011
44. Trivia array = [1,2,3] Friday, September 16, 2011
45. Trivia array = [1,2,3] array.length+1 Friday, September 16, 2011
46. Trivia array = [1,2,3] array.length+1 #=> 4 Friday, September 16, 2011
47. Trivia array = [1,2,3] array.length+1 #=> 4 array.length +1 Friday, September 16, 2011
48. Trivia array = [1,2,3] array.length+1 #=> 4 array.length +1 #=> ArgumentError Friday, September 16, 2011
49. Trivia array = [1,2,3] array.length+1 #=> 4 array.length +1 #=> ArgumentError array.length + 1 Friday, September 16, 2011
50. Trivia array = [1,2,3] array.length+1 #=> 4 array.length +1 #=> ArgumentError array.length + 1 #=> 4 Friday, September 16, 2011
51. Trivia p { } p { a: 1 } Is it a block or a hash? Friday, September 16, 2011
52. The Object Model Friday, September 16, 2011
53. object = Object.new def object.greet(name) puts "Hello #{name}" end object.greet("Matz") Friday, September 16, 2011
54. Ruby methods are stored in modules Friday, September 16, 2011
55. module Greeter def greet(name) "Hello #{name}" end end class Person include Greeter end Person.new.greet "Matz" Friday, September 16, 2011
56. class Person def greet(name) "Hello #{name}" end end Person.new.greet "Matz" Friday, September 16, 2011
57. Person.is_a?(Module) #=> true Class.superclass #=> Module Friday, September 16, 2011
58. object = Object.new def object.greet(name) puts "Hello #{name}" end object.greet("Matz") Friday, September 16, 2011
59. object.class.ancestors #=> [Object, Kernel, BasicObject] Friday, September 16, 2011
60. object.class.ancestors #=> [Object, Kernel, BasicObject] object.class.ancestors.any? do |r| r.method_defined?(:greet) end #=> false Friday, September 16, 2011
61. object.class.ancestors #=> [Object, Kernel, BasicObject] object.class.ancestors.any? do |r| r.method_defined?(:greet) end #=> false object.singleton_class. method_defined?(:greet) #=> true Friday, September 16, 2011
62. object.class.ancestors #=> [Object, Kernel, BasicObject] object.class.ancestors.any? do |r| r.method_defined?(:greet) end #=> false object.singleton_class. method_defined?(:greet) #=> true object.singleton_class.is_a?(Module) #=> true Friday, September 16, 2011
63. _why once said: Creating your own programming language is fun if you can keep it under 10k LOC Trivia Friday, September 16, 2011
64. Ruby’s parse.y is more than 10k LOC Trivia Friday, September 16, 2011
65. What if? Friday, September 16, 2011
66. ... we did not have blocks? Friday, September 16, 2011
67. <3 Blocks <3 Friday, September 16, 2011
68. File.open "gogaruco.txt" do |f| f.write "doing it live" end Friday, September 16, 2011
69. File.open "gogaruco.txt", do |f| f.write "doing it live" end Friday, September 16, 2011
70. File.open "gogaruco.txt", do |f| f.write "doing it live" end Friday, September 16, 2011
71. File.open("gogaruco.txt", do |f| f.write "doing it live" end) Friday, September 16, 2011
72. do_it = do |f| f.write "doing it live" end File.open "gogaruco.txt", do_it Friday, September 16, 2011
73. No blocks + No need for yield, &block + Passing more than one block around is more natural Friday, September 16, 2011
74. ... we had Array and Hash comprehensions? Friday, September 16, 2011
75. n = [1,2,3,4] [x * 2 for x in n] # => [2,4,6,8] Friday, September 16, 2011
76. n = [1,2,3] [x * 2 for x in n, x.odd?] # => [2,6] Friday, September 16, 2011
77. n = [1,2,3,4] [[x,y] for x in n, y in n, x * x == y] # => [[1,1],[2,4]] Friday, September 16, 2011
78. n = [1,2,3,4] {x => y for x in n, y in n, x * x == y} # => { 1 => 1, 2 => 4 } Friday, September 16, 2011
79. ... our hashes were more like JSON? Friday, September 16, 2011
80. { a: 1 } Friday, September 16, 2011
81. { "a": 1 } Friday, September 16, 2011
82. Trivia { "a-b": 1 } == { :"a-b" => 1 } Friday, September 16, 2011
83. ... we had (better) pattern matching? Friday, September 16, 2011
84. x, y, *z = [1,2,3,4,5] x #=> 1 y #=> 2 z #=> [3,4,5] Friday, September 16, 2011
85. x, [y1,*y2], *z = [1,[2,3,4],5] x #=> 1 y1 #=> 2 y2 #=> [3,4] z #=> [5] Friday, September 16, 2011
86. x, x, *z = [1,2,3,4,5] #=> Raises an error Friday, September 16, 2011
87. x, x, *z = [1,1,3,4,5] #=> Works! Friday, September 16, 2011
88. x = 1 ^x, *y = [3, 2, 1] #=> Raises an error! ^x, *y = [1, 2, 3] # => Works! Friday, September 16, 2011
89. def form_for(object) case object when Hash # ... when Array # ... else # ... end end Friday, September 16, 2011
90. def form_for(record : Hash) # ... end def form_for(record : Array) # ... end def form_for(record) # ... end Friday, September 16, 2011
91. + Better to maintain + Better to document - No duck typing Method pattern matching Friday, September 16, 2011
92. Haskell / Go interfaces interface ActiveModel::Compliance def :to_key def :persisted? end def form_for(object : ActiveModel::Compliance) # ... end Friday, September 16, 2011
93. ... we had partial application? Friday, September 16, 2011
94. _ has special semantics in many functional programming languages Friday, September 16, 2011
95. _ = 1 _ # => nil Friday, September 16, 2011
96. x, [y1,*_], *z = [1,[2,3,4],5] Friday, September 16, 2011
97. Instead of: names.each { |x| puts(x) } Friday, September 16, 2011
98. Instead of: names.each { |x| puts(x) } Do: names.each &puts(_) Friday, September 16, 2011
99. puts(_) #=> lambda { |x| puts(x) } respond_to?(_, _) #=> lambda { |x,y| respond_to?(x,y) } Friday, September 16, 2011
100. ... we defined a syntax tree? Friday, September 16, 2011
101. [:method,:bar,[ [:assign, "foo", [:integer,1]], [:var,"foo"] ]] Friday, September 16, 2011
102. class Foo memoize def bar # Something end end Friday, September 16, 2011
103. class Foo memoize(def bar # Something end) end Friday, September 16, 2011
104. def memoize(method) tree = method.tree # Do something method.redefine! new_tree end Friday, September 16, 2011
105. Wrapping up Friday, September 16, 2011
106. <3 Elixir <3 github.com/josevalim/elixir Friday, September 16, 2011
107. createyourproglang.com Friday, September 16, 2011
108. José Valim @josevalim blog.plataformatec.com Questions? Friday, September 16, 2011
109. blog twitter ID José Valim @josevalim blog.plataformatec.com Questions? Friday, September 16, 2011