Multiverse Ruby

Slides from my talk by the same name at RubyKaigi 2023, given in Japanese.

shioyama/im
shioyama/rails_on_im

Transcript

1. Multiverse Ruby Multiverse Ruby Chris Salzberg Chris Salzberg
2. @shioyama
3. Chris Salzberg Staff developer, Ruby and Rails Infra
4. 箱
5. 1.Sharing code in Ruby 2.Modules as Universes 3.Isolated Module Autoloader
6. Sharing code in Ruby
7. n = 10 a, b = 0, 1 n.times do a, b = b, a + b end puts a
8. def self.fib(n) a, b = 0, 1 n.times do a, b = b, a + b end a end
9. module Fibonacci def self.fib(n) a, b = 0, 1 n.times do a, b = b, a + b end a end end
10. module Fibonacci def self.fib(n) a, b = 0, 1 n.times do a, b = b, a + b end a end end code
11. module Fibonacci def self.fib(n) a, b = 0, 1 n.times do a, b = b, a + b end a end end architecture
12. In Ruby, we share code by sharing architecture.
13. that architecture is...
14. global
15. finite
16. permanent
17. Ruby’s architecture is not portable
19. Modules as Universes
20. Named Anonymous Modules
21. module Foo class Bar end end Named
22. module Foo class Bar end end mod = Module.new mod.name #=> nil Named Anonymous
23. mod = Module.new
24. mod = Module.new mod::Foo = Module.new
25. mod = Module.new mod::Foo = Module.new mod::Foo.name
26. mod = Module.new mod::Foo = Module.new mod::Foo.name #=> "#<Module:0x0...>::Foo"
27. mod = Module.new mod::Foo = Module.new mod::Foo.name #=> "#<Module:0x0...>::Foo" temporary name
28. // variable.c:138 static VALUE make_temporary_path(VALUE obj, VALUE klass) { VALUE path; switch (klass) { case Qnil: path = rb_sprintf("#<Class:%p>", (void*)obj); break; case Qfalse: path = rb_sprintf("#<Module:%p>", (void*)obj); break; default: path = rb_sprintf("#<%"PRIsVALUE":%p>", klass, (void*)obj); break; } OBJ_FREEZE(path); return path; }
29. mod::Foo.name #=> "#<Module:0x0...>::Foo" temporary name
30. mod::Foo.name #=> "#<Module:0x0...>::Foo" MyFoo = mod::Foo temporary name
31. mod::Foo.name #=> "#<Module:0x0...>::Foo" MyFoo = mod::Foo mod::Foo.name #=> "MyFoo" permanent name temporary name
32. Modules Named Anonymous
33. Modules temporary
34. temporary == portable
35. module Foo class Bar end end
36. mod = Module.new module mod::Foo class Bar end end
37. mod = Module.new module mod::Foo class Bar end end mod::Foo::Bar.name #=> "#<Module:0x0...>::Foo::Bar"
38. Object::Foo Object::Baz Object::Foo::Bar Object::Foo::Qux
39. Object Object::Foo Object::Baz Object::Foo::Bar Object::Foo::Qux Permanent Root
40. mod
41. mod::Foo mod::Baz mod::Foo::Bar mod::Foo::Qux mod Temporary Root
42. MyFoo = mod::Foo MyFoo::Bar MyFoo::Qux mod mod::Baz
43. MyGem::Foo MyGem::Baz MyGem::Foo::Bar MyGem::Foo::Qux MyGem = mod
44. a module is the root of a universe
45. Isolated Module Autoloader
46. require "my_gem"
47. 📦= import "my_gem"
48. RUBY 3.2 RUBY 3.2
54. module Fibonacci end fibonacci.rb module Fibonacci end load "fibonacci.rb"
55. module Fibonacci end fibonacci.rb module MyWrapper end load "fibonacci.rb", MyWrapper module Fibonacci end
56. module Fibonacci end fibonacci.rb module 📦 end load "fibonacci.rb", 📦 module Fibonacci end
57. import load ⇨ ?
58. require "my_gem" # my_gem.rb require "foo" require "bar" # foo.rb # bar.rb require require require require require
59. mod = import "my_gem" # my_gem.rb require "foo" require "bar" # foo.rb # bar.rb require require require require require load load load load load load load
60. mod = import "my_gem" # my_gem.rb require "foo" require "bar" # foo.rb # bar.rb require require require require require load load load load load load load
62. autoload
63. Object.autoload(:MyGem, "lib/my_gem.rb")
64. Object.autoload(:MyGem, "lib/my_gem.rb") mod
65. im i isolated solated m module odule autoloader autoloader i isolated solated m module odule autoloader autoloader
66. Im is a Zeitwerk fork
67. lib/my_gem.rb → MyGem lib/my_gem/foo.rb → MyGem::Foo lib/my_gem/bar_baz.rb → MyGem::BarBaz lib/my_gem/woo/zoo.rb → MyGem::Woo::Zoo Zeitwerk: Code Loader
68. Zeitwerk: Code Loader lib/my_gem.rb → MyGem lib/my_gem/foo.rb → MyGem::Foo lib/my_gem/bar_baz.rb → MyGem::BarBaz lib/my_gem/woo/zoo.rb → MyGem::Woo::Zoo Object:: Object:: Object:: Object::
69. lib/my_gem.rb → MyGem lib/my_gem/foo.rb → MyGem::Foo lib/my_gem/bar_baz.rb → MyGem::BarBaz lib/my_gem/woo/zoo.rb → MyGem::Woo::Zoo Im: Isolated Code Loader mod:: mod:: mod:: mod:: temporary root
70. mod = import "my_gem"
71. mod = import "my_gem" mod::MyGem::Foo #=> loads "lib/my_gem/foo.rb"
72. mod = import "my_gem" mod::MyGem::Foo #=> loads "lib/my_gem/foo.rb" mod::MyGem::Foo::BarBaz #=> loads "lib/my_gem/foo/bar_baz.rb"
73. mod = import "my_gem" mod::MyGem::Foo #=> loads "lib/my_gem/foo.rb" mod::MyGem::Foo::BarBaz #=> loads "lib/my_gem/foo/bar_baz.rb" mod::MyGem::Foo::Woo::Zoo #=> loads "lib/my_gem/foo/woo/zoo.rb"
74. Im is compatible with Zeitwerk
75. 実装
76. # lib/zeitwerk/loader/config.rb unless real_mod_name(namespace) raise Zeitwerk::Error, "root namespaces cannot be anonymous" end
77. # lib/zeitwerk/loader/config.rb unless real_mod_name(namespace) raise Zeitwerk::Error, "root namespaces cannot be anonymous" end
78. # lib/zeitwerk/loader.rb module Zeitwerk class Loader
79. # lib/im/loader.rb module Im class Loader < Module root of the universe
80. loader::Foo loader::Baz loader::Foo::Bar loader::Foo::Qux loader
81. # lib/my_gem.rb (main file) require "zeitwerk" loader = Zeitwerk::Loader.for_gem loader.setup # ready! module MyGem # ... end loader.eager_load # optionally
82. # lib/my_gem.rb (main file) require "im" loader = Im::Loader.for_gem loader.setup # ready! module loader::MyGem # ... end loader.eager_load # optionally define under loader, not at top-level!
83. def require(path) filetype, feature_path = $:.resolve_feature_path(path) if (loader = Im::Registry.loader_for(path)) # ... $LOADED_FEATURES << feature_path begin load path, loader rescue => e $LOADED_FEATURES.delete(feature_path) raise e end
84. def require(path) filetype, feature_path = $:.resolve_feature_path(path) if (loader = Im::Registry.loader_for(path)) # ... $LOADED_FEATURES << feature_path begin load path, loader rescue => e $LOADED_FEATURES.delete(feature_path) raise e end
85. def require(path) filetype, feature_path = $:.resolve_feature_path(path) if (loader = Im::Registry.loader_for(path)) # ... $LOADED_FEATURES << feature_path begin load path, loader rescue => e $LOADED_FEATURES.delete(feature_path) raise e end
86. def require(path) filetype, feature_path = $:.resolve_feature_path(path) if (loader = Im::Registry.loader_for(path)) # ... $LOADED_FEATURES << feature_path begin load path, loader rescue => e $LOADED_FEATURES.delete(feature_path) raise e end 🙈
87. - assert A::X - assert B::X + assert loader::A::X + assert loader::B::X
88. ........................................................... ........................................................... ........................................................... ........................................................... ........................................................... ........................................................... .................................... Finished tests in 2.968770s, 131.3675 tests/s, 319.6610 assertions/s. 390 tests, 949 assertions, 0 failures, 0 errors, 0 skips 🎉
89. The cpath problem
90. def cpath(parent, cname) "#{parent.name}::#{cname}" end
91. def cpath(parent, cname) "#{parent.name}::#{cname}" end Foo :Bar
92. def cpath(parent, cname) "#{parent.name}::#{cname}" end Foo :Bar #=> "Foo::Bar" cpath
93. { "Foo" ⇨ <#Zeitwerk::Loader>, "Foo::Bar" ⇨ <#Zeitwerk::Loader>, # ... } cpath Zeitwerk
94. { "<#Im::Loader>::Foo" ⇨ ... "<#Im::Loader>::Foo::Bar" ⇨ ... # ... } cpath Im
95. MyFoo = mod::Foo
96. temporary permanent "#<...>::Foo" "MyFoo" MyFoo = mod::Foo
97. { "<#Im::Loader>::Foo" ⇨ ... "<#Im::Loader>::Foo::Bar" ⇨ ... # ... } cpaths["MyFoo"] #=> nil
98. assert loader::A X = loader::A assert loader::A assert loader::A::B assert loader::A::B::C assert_equal(X::B::C, loader::A::B::C) FAIL ❌
99. RUBY RUBY 3.2 3.2
101. Foo::BAR = 42 Foo.const_added(:BAR) callback
102. MyFoo = mod::Foo Object.const_added(:MyFoo) callback
103. module Im::ModuleConstAdded def const_added(const_name) # ... ::Im::ExplicitNamespace.__update_cpaths( prefix, "#{cpath}::#{const_name}" ) super end end ::Module.prepend(Im::ModuleConstAdded)
104. module Im::ModuleConstAdded def const_added(const_name) # ... ::Im::ExplicitNamespace.__update_cpaths( prefix, "#{cpath}::#{const_name}" ) super end end ::Module.prepend(Im::ModuleConstAdded)
105. { "<#Im::Loader ...>" ⇨ ... "<#Im::Loader ...>::Foo" ⇨ ... "<#Im::Loader ...>::Foo::Bar" ⇨ ... ... } cpath
106. { "<#Im::Loader ...>" ⇨ ... "MyFoo" ⇨ ... "MyFoo::Bar" ⇨ ... ... } cpath Object.const_added(:MyFoo)
107. assert loader::A X = loader::A assert loader::A assert loader::A::B assert loader::A::B::C assert_equal(X::B::C, loader::A::B::C) PASS ✅
108. gem "im", "~> 0.2.2"
113. Chris Salzberg @shioyama github:shioyama/im github:shioyama/rails_on_im