[RubyConf 2018] Ruby Next: Make old Rubies quack like a new one

GitHub: https://github.com/ruby-next/ruby-next
Video: https://www.youtube.com/watch?v=T6epHXlUmG0

Ruby 2.7 is just around the corner. It will bring a lot of new features, including new syntax additions: pattern matching, numbered parameters.

That's good news. The bad news is that not many of us will be able to use these goodies right away: the upgrade cost blocks application developers; gem authors have to support older versions.

What if we were able to use Ruby Next features while running Ruby Current? Maybe, we can cast a metaprogramming spell for that? Yes, we can. And I'll show you how.

Transcript

1. palkan_tula palkan RubyConf 2019 Ruby Next Vladimir Dementyev Evil Martians
2. 142 palkan_tula palkan RubyConf 2019 2 Ruby
3. 142 palkan_tula palkan RubyConf 2019 Features & challenges 3
4. 142 palkan_tula palkan RubyConf 2019 Challenges for Ruby developers 4
5. 142 palkan_tula palkan RubyConf 2019 5 Ruby Next
6. 142 palkan_tula palkan RubyConf 2019 Make old Rubies quack like a new one 6
7. 142 palkan_tula palkan RubyConf 2019 $ ruby -v
 2.5.3p105
 $ ruby -e "
 case {hello: 'RubyConf'}
 in hello: hello if hello =~ /Rails/
 puts 'My name is David'
 in hello: 'RubyConf'
 puts 'My name is Vova'
 end"
 -e:3: syntax error, unexpected in, expecting when in hello: if hello =~ /Rails/ 7 tl;dr
8. 142 palkan_tula palkan RubyConf 2019 $ ruby -v
 2.5.3p105
 $ ruby -ruby-next -e "
 case {hello: 'RubyConf'}
 in hello: hello if hello =~ /Rails/
 puts 'My name is David'
 in hello: 'RubyConf'
 puts 'My name is Vova'
 end"
 My name is Vova 8 tl;dr
9. 142 palkan_tula palkan RubyConf 2019 9 About me
10. 142 palkan_tula palkan RubyConf 2019 Evil Martian 10
11. 142 palkan_tula palkan RubyConf 2019 evilmartians.com 11
12. 142 palkan_tula palkan RubyConf 2019 12 evilmartians.com What's next ?
13. 142 palkan_tula palkan RubyConf 2019 Ruby and !Ruby developer 13
14. 142 palkan_tula palkan RubyConf 2019 github.com/palkan 14
15. 142 palkan_tula palkan RubyConf 2019 Gems author 15
16. 142 palkan_tula palkan RubyConf 2019 rubygems.org/profiles/palkan 16
17. 142 palkan_tula palkan RubyConf 2019 I have to write Ruby code compatible with older versions 17
18. 142 palkan_tula palkan RubyConf 2019 18 2.3 — 2019-03-31 2.4 — 2020-03-31 ⏳ Ruby EOL
19. 142 palkan_tula palkan RubyConf 2019 spec.require_ruby_version = " >= 2.5.0" 19
20. 142 palkan_tula palkan RubyConf 2019 I want to use 2.7 features 20
21. 142 palkan_tula palkan RubyConf 2019 Not everyone is a gem maintainer 21
22. 142 palkan_tula palkan RubyConf 2019 jetbrains.com/lp/devecosystem-2019/ruby/ 22
23. 142 palkan_tula palkan RubyConf 2019 “30% reported that they're not about to switch” 23
24. 142 palkan_tula palkan RubyConf 2019 Performance Why upgrade? 24
25. 142 palkan_tula palkan RubyConf 2019 Performance New features Why upgrade? 25
26. 142 palkan_tula palkan RubyConf 2019 26 Story time
27. 142 palkan_tula palkan RubyConf 2019 Jan 2018, Ruby 2.5 27
28. 142 palkan_tula palkan RubyConf 2019 28 #yield_self
29. 142 palkan_tula palkan RubyConf 2019 module Kernel def yield_self yield self end end 29 Metaprogramming for good
30. 142 palkan_tula palkan RubyConf 2019 30 #then
31. 142 palkan_tula palkan RubyConf 2019 module YieldSelfThen refine Kernel do unless nil.respond_to?(:yield_self) def yield_self yield self end end alias then yield_self end end 31 Metaprogramming for good
32. 142 palkan_tula palkan RubyConf 2019 Refinements 32
33. 142 palkan_tula palkan RubyConf 2019 Introduced in 2.0 Has been experimental until 2.1 Getting better with every release Won't go away in 3.0 History 33
34. 142 palkan_tula palkan RubyConf 2019 Lexically scoped monkey-patch 34
35. 142 palkan_tula palkan RubyConf 2019 Refinements changed the way method lookup work 35
36. 142 palkan_tula palkan RubyConf 2019 def send(mid, *args) # iterate through the ancestors chain # (included/prepended modules and classes) k = self.class iter = self.class.ancestors.each loop do if k.instance_methods(false).include?(mid) return k.instance_method(mid) .bind_call(self, *args) end k = iter.next end end 36 Regular lookup
37. 142 palkan_tula palkan RubyConf 2019 def send(mid, *args) k = self.class iter = self.class.ancestors.each loop do meth = + # lookup refinements in the execution context + if context.refinements_for(k)&.include?(mid) + context.refinements_for(k)[mid] - if k.instance_methods(false).include?(mid) + elsif k.instance_methods(false).include?(mid) k.instance_method(mid) end return meth.bind_call(self, *args) if meth k = iter.next end end 37 Refined lookup
38. 142 palkan_tula palkan RubyConf 2019 “Refinements... Not fun.” — Ruby Implementation developer 38
39. 142 palkan_tula palkan RubyConf 2019 JRuby vs refinements 39 15 issues were closed in 2019
40. 142 palkan_tula palkan RubyConf 2019 Define refinement via refine Activate refinement via using 40
41. 142 palkan_tula palkan RubyConf 2019 module YieldSelfThen refine Kernel do unless nil.respond_to?(:yield_self) def yield_self yield self end end alias then yield_self end end 41 Define
42. 142 palkan_tula palkan RubyConf 2019 using YieldSelfThen p Gem ::Version.new(RUBY_VERSION).then { |v| v.segments[0 ..1].join(".") } # => "2.5" 42 Activate
43. 142 palkan_tula palkan RubyConf 2019 # succ.rb
 using YieldSelfThen
 
 p ARGV[0].then { |i| i.to_i + 1 } 
 # prec.rb
 p ARGV[0].then { |i| i.to_i - 1 } 
 $ ruby succ.rb 2
 3 
 $ ruby prec.rb 3
 undefined method `then' for "3":String 43 Lexical
44. 142 palkan_tula palkan RubyConf 2019 Safe monkey-patch 44
45. 142 palkan_tula palkan RubyConf 2019 We can use refinements to safely “backport” new APIs 45
46. 142 palkan_tula palkan RubyConf 2019 Ruby gets new APIs with every minor release 46
47. 142 palkan_tula palkan RubyConf 2019 47 Kernel#yield_self Thread#fetch Hash#transform_keys Hash#slice 2.5
48. 142 palkan_tula palkan RubyConf 2019 48 Kernel#then Proc# >>/# << Enumerable#filter Array#union/#difference 2.6
49. 142 palkan_tula palkan RubyConf 2019 49 2.7 Enumerable#tally Enumerable#filter_map Time#ceil/#floor UnboundMethod#bind_call
50. 142 palkan_tula palkan RubyConf 2019 rubyreferences.github.io/rubychanges/ 50
51. 142 palkan_tula palkan RubyConf 2019 One refinement to rule them all 51 Ruby Next 2018
52. 142 palkan_tula palkan RubyConf 2019 # stats.rb using RubyNext Dir["**/*"].filter_map do |path| next if path =~ %r{[$/]m?spec} File.extname(path) end.tally.sort_by(&:last).reverse_each do |(ext, count)| puts " #{count}\t #{ext}" end 52
53. 142 palkan_tula palkan RubyConf 2019 # stats.rb using RubyNext Dir["**/*"].filter_map do |path| next if path =~ %r{[$/]m?spec} File.extname(path) end.tally.sort_by(&:last).reverse_each do |(ext, count)| puts " #{count}\t #{ext}" end 53
54. 142 palkan_tula palkan RubyConf 2019 $ ruby -ruby-next stats.rb 67 .rb 50 5 .md 2 .lock 1 .txt 1 .mspec 1 .gemspec 1 .gemfile 1 .bat 1 .dict 54
55. 142 palkan_tula palkan RubyConf 2019 55 Only contains undefined or modified methods => no-op in Ruby 2.7 using RubyNext
56. 142 palkan_tula palkan RubyConf 2019 That's what Ruby Next could be but... 56
57. 142 palkan_tula palkan RubyConf 2019 Ruby 2.7 adds a lot of new syntax features 57
58. 142 palkan_tula palkan RubyConf 2019 Pattern matching: case i; in ... end Numbered params: -> { _1 + _2 } Ruby 2.7 58
59. 142 palkan_tula palkan RubyConf 2019 Method reference: d.then(JSON.:parse) Args forwarding: def foo( ...) bar( ...) Ruby 2.7 59
60. 142 palkan_tula palkan RubyConf 2019 We cannot refine syntax 60
61. 142 palkan_tula palkan RubyConf 2019 Let's transpile it! 61
62. 142 palkan_tula palkan RubyConf 2019 Polyfills (universal refinement) Transpiler RubyNext 2019 62
63. 142 palkan_tula palkan RubyConf 2019 Transpiling 63
64. 142 palkan_tula palkan RubyConf 2019 Transpiling 64 transpiler Ruby 2.7 source code Ruby 2.5 source code
65. 142 palkan_tula palkan RubyConf 2019 Ruby Next is Babel for Ruby? 65
66. 142 palkan_tula palkan RubyConf 2019 RubyNext is PostCSS for Ruby? 66
67. 142 palkan_tula palkan RubyConf 2019 Transpiling 67 source code new old source code AST new old AST
68. 142 palkan_tula palkan RubyConf 2019 def beach(*temperature) case temperature in :celcius | :c, (20 ..45) :favorable in :kelvin | :k, (293 ..318) :scientifically_favorable in :fahrenheit | :f, (68 ..113) :favorable_in_us else :avoid_beach end end 68 Example
69. 142 palkan_tula palkan RubyConf 2019 69 Ripper Source to AST
70. 142 palkan_tula palkan RubyConf 2019 $ ruby -r ripper -e "pp Ripper.sexp(File.read('beach.rb'))" [:program, [[:def, [:@ident, "beach", [1, 4]], [:paren, [:params, [:rest_param, [:@ident, "temperature", [1, 11]]], ], [:bodystmt, [[:case, [:var_ref, [:@ident, "temperature", [2, 7]]], [:in, [:aryptn, nil, [[:binary, [:symbol_literal, [:symbol, [:@ident, "celcius", [3, 6]]]], 70
71. 142 palkan_tula palkan RubyConf 2019 Since 1.9 Version-specific Ripper 71
72. 142 palkan_tula palkan RubyConf 2019 $ ruby -v
 2.5.3p105 $ ruby -r ripper -e "pp Ripper.sexp(File.read('beach.rb'))" nil 72
73. 142 palkan_tula palkan RubyConf 2019 preval 73 github.com/kddeisz/preval
74. 142 palkan_tula palkan RubyConf 2019 74 Ripper RubyVM::AbstractSyntaxTree Source to AST
75. 142 palkan_tula palkan RubyConf 2019 $ ruby -e "pp RubyVM ::AbstractSyntaxTree.parse_file('beach.rb')" (SCOPE@1:0-14:3 body: (DEFN@1:0-14:3 mid: :beach body: (SCOPE@1:0-14:3 tbl: [:temperature] args: ... body: (CASE3@2:2-13:5 (LVAR@2:7-2:18 :temperature) (IN@3:2-12:16 (ARYPTN@3:5-3:28 const: nil pre: (LIST@3:5-3:28 75
76. 142 palkan_tula palkan RubyConf 2019 New in 2.6 MRI-specific Version-specific RubyVM ::AbstractSyntaxTree 76
77. 142 palkan_tula palkan RubyConf 2019 77 Ripper RubyVM::AbstractSyntaxTree Parser Source to AST
78. 142 palkan_tula palkan RubyConf 2019 $ gem install parser $ ruby-parse ./beach.rb (def :beach (args (restarg :temperature)) (case-match (lvar :temperature) (in-pattern (array-pattern (match-alt (sym :celcius) (sym :c)) (begin (irange (int 20) (int 45)))) nil 78
79. 142 palkan_tula palkan RubyConf 2019 Written in pure Ruby Version-independent Bullet-proofed (e.g., by RuboCop) Parser 79
80. 142 palkan_tula palkan RubyConf 2019 80 Parser Born at Evil Martians
81. 142 palkan_tula palkan RubyConf 2019 81 Unparser $ gem install unparser 
 $ ruby -r parser/current -r unparser -e "
 p Unparser.unparse(
 Parser ::CurrentRuby.parse('%i[a a b c].tally'))
 " "[:a, :a, :b, :c].tally"
82. 142 palkan_tula palkan RubyConf 2019 82 Unparser $ gem install unparser 
 $ ruby -r parser/current -r unparser -e "
 p Unparser.unparse(
 Parser ::CurrentRuby.parse('%i[a a b c].tally'))
 " "[:a, :a, :b, :c].tally"
83. 142 palkan_tula palkan RubyConf 2019 83 <<"A #{b}C" #{ <<"A #{b}C" A #{b}C } str A #{b}C 
 # => "\nstr\n" Parser is not ideal (dstr (begin (dstr (str "A") (begin (send nil :b)))) (str "\n") (str "str\n") (str "A") (begin (send nil :b)))) " #{"A #{b}"}\nstr\nA #{b}" # => undefined local variable or method `b'
84. 142 palkan_tula palkan RubyConf 2019 Parser is good enough for now 84
85. 142 palkan_tula palkan RubyConf 2019 Parse Ruby code using edge parser Replace unsupported AST nodes with equivalents for the target version Generate new source code with unparser Ruby Next 85
86. 142 palkan_tula palkan RubyConf 2019 def transform(source) Parser.parse(source).then do |ast| rewriters.inject(ast) do |tree, rewriter| rewriter.new.process(tree) end.then do |new_ast| Unparser.unparse(new_ast) end end end end 86
87. 142 palkan_tula palkan RubyConf 2019 module Rewriters class MethodReference < Base def on_meth_ref(node) receiver, mid = *node.children node.updated( # (meth-ref :send, # (const nil :C) :m) [ # receiver, # -> :method, # s(:sym, mid) # (send ] # (const nil :C) :method ) # (sym :m) end end end 87
88. 142 palkan_tula palkan RubyConf 2019 module Rewriters class PatternMatching < Base def on_case_match(node) # ~500 LOC end end end 88
89. 142 palkan_tula palkan RubyConf 2019 if ... else if ... else ... end #deconstruct & #deconstruct_keys Type and structure checks “Pattern matching” in <2.7 89
90. 142 palkan_tula palkan RubyConf 2019 90 def fizzbuzz(num) rems = [num % 3, num % 5] if rems == [0, 0]
 'FizzBuzz' elsif rems[0] == 0
 'Fizz'
 elsif rems[1] == 1
 'Buzz' else
 raise "NoMatchingPattern"
 end
 end def fizzbuzz(num) case [num % 3, num % 5] in [0, 0] then 'FizzBuzz' in [0, _] then 'Fizz' in [_, 0] then 'Buzz' end end 2.7 2.5 ad-hoc rewrite
91. 142 palkan_tula palkan RubyConf 2019 91 def fizzbuzz(num) vals = [num % 3, num % 5]
 .deconstruct raise TypeError unless Array === vals if (0 === vals[0]) &&
 (0 === vals[1]) 
 'FizzBuzz' elsif (0 === vals[0])
 && (_ == vals[1] || true)
 'Fizz'
 elsif (_ == vals[0] || true)
 && (1 === vals[1])
 'Buzz' else
 raise "NoMatchingPattern"
 end
 end def fizzbuzz(num) case [num % 3, num % 5] in [0, 0] then 'FizzBuzz' in [0, _] then 'Fizz' in [_, 0] then 'Buzz' end end 2.7 2.5 transpile
92. 142 palkan_tula palkan RubyConf 2019 $ gem install ruby-next $ ruby-next nextify ./beach.rb -o stdout def beach(*temperature)
 __matchee __ = temperature
 if (((( __matchee_arr __ = __matchee __.deconstruct) || true) && ((Array === __matchee_arr __) || Kernel.raise(TypeError, __matchee __.inspect))) && ((2 == __matchee_arr __.size) && (((:celcius === __matchee_arr __[0]) || (:c === __matchee_arr __[0])) && ((20 ..45) === __matchee_arr __[1]))))
 :favorable
 else
 if (((:kelvin === __matchee_arr __[0]) || (:k === __matchee_arr __[0])) && ((293 ..318) === __matchee_arr __[1]))
 :scientifically_favorable
 else
 if (((:fahrenheit === __matchee_arr __[0]) || (:f === __matchee_arr __[0])) && ((68 ..113) === __matchee_arr __[1]))
 :favorable_in_us
 else
 :avoid_beach
 end
 end
 end
 end 92
93. 142 palkan_tula palkan RubyConf 2019 93 def beach(*temperature)
 __matchee __ = temperature
 if (((( __matchee_arr __ = __matchee __.deconstruct) || true) && ((Array === __matchee_arr __) || Kernel.raise(TypeError, __matchee __.inspect))) && ((2 == __matchee_arr __.size) && (((:celcius === __matchee_arr __[0]) || (:c === __matchee_arr __[0])) && ((20 ..45) === __matchee_arr __[1]))))
 :favorable
 else
 if (((:kelvin === __matchee_arr __[0]) || (:k === __matchee_arr __[0])) && ((293 ..318) === __matchee_arr __[1]))
 :scientifically_favorable
 else
 if (((:fahrenheit === __matchee_arr __[0]) || (:f === __matchee_arr __[0])) && ((68 ..113) === __matchee_arr __[1]))
 :favorable_in_us
 else
 :avoid_beach
 end
 end
 end
 end def beach(*temperature) case temperature in :celcius | :c, (20 ..45) :favorable in :kelvin | :k, (293 ..318) :scientifically_favorable in :fahrenheit | :f, (68 ..113) :favorable_in_us else :avoid_beach end end For humans For machines
94. 142 palkan_tula palkan RubyConf 2019 Transpiling vs. performance 94
95. 142 palkan_tula palkan RubyConf 2019 def beach(*temperature) case temperature in :celcius | :c, (20 ..45) :favorable in :kelvin | :k, (293 ..318) :scientifically_favorable in :fahrenheit | :f, (68 ..113) :favorable_in_us else :avoid_beach end end $ ruby benchmark/pattern_matching_array.rb Comparison:
 transpiled: 2165271.2 i/s 
 baseline: 1004383.8 i/s - 2.16x slower 95
96. 142 palkan_tula palkan RubyConf 2019 case JSON.parse(ARGV[0], symbolize_names: true) in {name: "Alice", children: [{name: "Bob", age: age}]} p "Bob age is #{age}" in _ "No Alice" end $ ruby benchmark/pattern_matching_mixed.rb Comparison:
 transpiled: 314105.5 i/s
 baseline: 273998.7 i/s - 1.15x slower 96
97. 142 palkan_tula palkan RubyConf 2019 How to integrate a transpiler into an interpreted language? 97
98. 142 palkan_tula palkan RubyConf 2019 Gems: transpile at “build”/ release time Apps/Scripts: transpile at runtime 98
99. 142 palkan_tula palkan RubyConf 2019 Hijack Kernel#require & co Reimplement require mechanism Runtime 99
100. 142 palkan_tula palkan RubyConf 2019 module Kernel module_function alias_method :require_without_ruby_next, :require def require(path) RubyNext.require(path) rescue => e warn "Failed to require ' #{path}': #{e.message}" require_without_ruby_next(path) end end 100 Kernel#require *Don't try this at home
101. 142 palkan_tula palkan RubyConf 2019 $LOAD_PATH: where to search for “features” $LOADED_FEATURES: required files Two pillars of require 101
102. 142 palkan_tula palkan RubyConf 2019 module RubyNext module_function def require(path) realpath = resolve_feature_path(path) return false if $LOADED_FEATURES.include?(realpath) File.read(realpath) .then(&Language.:transform).then do |source| TOPLEVEL_BINDING.eval source, path $LOADED_FEATURES << path true end end end 102 RubyNext.require
103. 142 palkan_tula palkan RubyConf 2019 module RubyNext module_function def require(path) realpath = resolve_feature_path(path) return false if $LOADED_FEATURES.include?(realpath) File.read(realpath) .then(&Language.:transform).then do |source| TOPLEVEL_BINDING.eval source, path $LOADED_FEATURES << path true end end end 103 RubyNext.require
104. 142 palkan_tula palkan RubyConf 2019 module RubyNext module_function def resolve_feature_path(path) path = " #{path}.rb" if File.extname(path).empty? return path if Pathname.new(path).absolute? $LOAD_PATH.find do |lp| lpath = File.join(lp, path) return lpath if File.file?(lpath) end end end 104
105. 142 palkan_tula palkan RubyConf 2019 module RubyNext module_function def resolve_feature_path(path) path = " #{path}.rb" if File.extname(path).empty? return path if Pathname.new(path).absolute? $LOAD_PATH.find do |lp| lpath = File.join(lp, path) return lpath if File.file?(lpath) end end end 105
106. 142 palkan_tula palkan RubyConf 2019 module RubyNext module_function def require(path) realpath = resolve_feature_path(path) return false if $LOADED_FEATURES.include?(realpath) File.read(realpath) .then(&Language.:transform).then do |source| TOPLEVEL_BINDING.eval source, path $LOADED_FEATURES << path true end end end 106 RubyNext.require
107. 142 palkan_tula palkan RubyConf 2019 module RubyNext module_function def require(path) realpath = resolve_feature_path(path) return false if $LOADED_FEATURES.include?(realpath) File.read(realpath) .then(&Language.:transform).then do |source| TOPLEVEL_BINDING.eval source, path $LOADED_FEATURES << path true end end end 107 RubyNext.require
108. 142 palkan_tula palkan RubyConf 2019 $ ruby -ruby-next -e "
 case {eta: ARGV[0].to_i}
 in eta: (0 ...10)
 puts 'The end is near'
 in eta: x if x > 10
 puts 'Boooring'
 end" 8
 The end is near 108 -ruby-next
109. 142 palkan_tula palkan RubyConf 2019 ruby -ruby-next == ruby -r uby-next 109
110. 142 palkan_tula palkan RubyConf 2019 110
111. 142 palkan_tula palkan RubyConf 2019 Runtime mode is meant for tests and playgrounds 111
112. 142 palkan_tula palkan RubyConf 2019 112 # test_helper.rb require 'ruby-next/runtime' Runtime in tests
113. 142 palkan_tula palkan RubyConf 2019 113 # boot.rb require 'bootsnap/setup' require 'ruby-next/bootsnap' Runtime future
114. 142 palkan_tula palkan RubyConf 2019 Add transpiled files to releases No additional runtime deps* Nextify Gems 114 * polyfills might still be required
115. 142 palkan_tula palkan RubyConf 2019 $ ruby-next nextify ./lib -V
 Generated: ./lib/.rbnext/rubanok/rule.rb
 Generated: ./lib/.rbnext/rubanok/dsl/matching.rb 115
116. 142 palkan_tula palkan RubyConf 2019 116 # lib/my_gem.rb require "ruby-next/language/setup" RubyNext ::Language.setup_gem_load_path
117. 142 palkan_tula palkan RubyConf 2019 117 def setup_gem_load_path lib_dir = File.dirname(caller_locations(1, 1).first.path) current_index = $LOAD_PATH.index(lib_dir) next_dir = File.join(lib_dir, ".rbnext") if File.exist?(next_dir) $LOAD_PATH.insert current_index, next_dir current_index += 1 end end setup_gem_load_path
118. 142 palkan_tula palkan RubyConf 2019 github.com/ruby-next/ruby-next 118
119. 142 palkan_tula palkan RubyConf 2019 Supported features 119 github.com/ruby-next/ruby-next/blob/master/SUPPORTED_FEATURES.md
120. 142 palkan_tula palkan RubyConf 2019 Compatibility matters 120
121. 142 palkan_tula palkan RubyConf 2019 ruby/spec ruby/ruby/test/* Ruby Next tests 121
122. 142 palkan_tula palkan RubyConf 2019 What's next? 122
123. 142 palkan_tula palkan RubyConf 2019 Make old all Rubies quack like a new one 123
124. 142 palkan_tula palkan RubyConf 2019 JRuby TruffleRuby mruby Opal Artichoke Prism Other Rubies 124
125. 142 palkan_tula palkan RubyConf 2019 The role of Ruby Next? 125
126. 142 palkan_tula palkan RubyConf 2019 Performance New features Why upgrade? 126
127. 142 palkan_tula palkan RubyConf 2019 Performance Experimental features Why upgrade? 127
128. 142 palkan_tula palkan RubyConf 2019 128 Experimental
129. 142 palkan_tula palkan RubyConf 2019 Experimental 129
130. 142 palkan_tula palkan RubyConf 2019 Experimental 130
131. 142 palkan_tula palkan RubyConf 2019 Expelliarmus 131
132. 142 palkan_tula palkan RubyConf 2019 We need an experiment 132
133. 142 palkan_tula palkan RubyConf 2019 133 |> 2019-06-13 — 2019-08-29
134. 142 palkan_tula palkan RubyConf 2019 134 .: 2018-12-31 — 2019-11-12
135. 142 palkan_tula palkan RubyConf 2019 Do we have a process? 135
136. 142 palkan_tula palkan RubyConf 2019 Example: TC39 136
137. 142 palkan_tula palkan RubyConf 2019 “will require feedback from ... users” ☝ 137
138. 142 palkan_tula palkan RubyConf 2019 Babel 138 https://scotch.io/tutorials/javascript-transpilers-what-they-are-why-we-need-them
139. 142 palkan_tula palkan RubyConf 2019 The best way to taste new features is to start using them every day 139
140. 142 palkan_tula palkan RubyConf 2019 Don't wait for Christmas to give new Ruby a try 140
141. 142 palkan_tula palkan RubyConf 2019 Start using RubyNext 141
142. palkan_tula palkan RubyConf 2019 Thank you! Vladimir Dementyev @ruby-next Evil Martians @palkan @palkan_tula evilmartians.com @evilmartians