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Multiverse Ruby
Multiverse Ruby
Chris Salzberg
Chris Salzberg
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@shioyama
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Chris Salzberg
Staff developer, Ruby and Rails Infra
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箱
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1.Sharing code in Ruby
2.Modules as Universes
3.Isolated Module Autoloader
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Sharing code in Ruby
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n = 10
a, b = 0, 1
n.times do
a, b = b, a + b
end
puts a
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def self.fib(n)
a, b = 0, 1
n.times do
a, b = b, a + b
end
a
end
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module Fibonacci
def self.fib(n)
a, b = 0, 1
n.times do
a, b = b, a + b
end
a
end
end
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module Fibonacci
def self.fib(n)
a, b = 0, 1
n.times do
a, b = b, a + b
end
a
end
end
code
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module Fibonacci
def self.fib(n)
a, b = 0, 1
n.times do
a, b = b, a + b
end
a
end
end
architecture
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In Ruby, we share code
by sharing architecture.
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that architecture is...
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global
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finite
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permanent
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Ruby’s architecture is not portable
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No content
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Modules as Universes
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Named Anonymous
Modules
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module Foo
class Bar
end
end
Named
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module Foo
class Bar
end
end
mod = Module.new
mod.name
#=> nil
Named Anonymous
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mod = Module.new
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mod = Module.new
mod::Foo = Module.new
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mod = Module.new
mod::Foo = Module.new
mod::Foo.name
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mod = Module.new
mod::Foo = Module.new
mod::Foo.name
#=> "#::Foo"
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mod = Module.new
mod::Foo = Module.new
mod::Foo.name
#=> "#::Foo"
temporary name
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// variable.c:138
static VALUE
make_temporary_path(VALUE obj, VALUE klass)
{
VALUE path;
switch (klass) {
case Qnil:
path = rb_sprintf("#", (void*)obj);
break;
case Qfalse:
path = rb_sprintf("#", (void*)obj);
break;
default:
path = rb_sprintf("#<%"PRIsVALUE":%p>", klass, (void*)obj);
break;
}
OBJ_FREEZE(path);
return path;
}
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mod::Foo.name
#=> "#::Foo"
temporary name
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mod::Foo.name
#=> "#::Foo"
MyFoo = mod::Foo
temporary name
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mod::Foo.name
#=> "#::Foo"
MyFoo = mod::Foo
mod::Foo.name
#=> "MyFoo"
permanent name
temporary name
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Modules
Named Anonymous
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Modules
temporary
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temporary == portable
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module Foo
class Bar
end
end
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mod = Module.new
module mod::Foo
class Bar
end
end
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mod = Module.new
module mod::Foo
class Bar
end
end
mod::Foo::Bar.name
#=> "#::Foo::Bar"
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Object::Foo Object::Baz
Object::Foo::Bar
Object::Foo::Qux
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Object
Object::Foo Object::Baz
Object::Foo::Bar
Object::Foo::Qux
Permanent Root
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mod
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mod::Foo mod::Baz
mod::Foo::Bar
mod::Foo::Qux
mod
Temporary Root
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MyFoo = mod::Foo
MyFoo::Bar
MyFoo::Qux
mod
mod::Baz
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MyGem::Foo MyGem::Baz
MyGem::Foo::Bar
MyGem::Foo::Qux
MyGem = mod
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a module is the root of a universe
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Isolated Module Autoloader
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require "my_gem"
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📦= import "my_gem"
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RUBY 3.2
RUBY 3.2
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module Fibonacci
end
fibonacci.rb
module Fibonacci
end
load "fibonacci.rb"
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module Fibonacci
end
fibonacci.rb module MyWrapper
end
load "fibonacci.rb", MyWrapper
module Fibonacci
end
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module Fibonacci
end
fibonacci.rb module
📦
end
load "fibonacci.rb",
📦
module Fibonacci
end
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import load
⇨ ?
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require "my_gem"
# my_gem.rb
require "foo"
require "bar"
# foo.rb
# bar.rb
require
require
require
require
require
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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
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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
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autoload
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Object.autoload(:MyGem, "lib/my_gem.rb")
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Object.autoload(:MyGem, "lib/my_gem.rb")
mod
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im i
isolated
solated
m
module
odule
autoloader
autoloader
i
isolated
solated
m
module
odule
autoloader
autoloader
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Im is a Zeitwerk fork
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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
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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::
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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
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mod = import "my_gem"
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mod = import "my_gem"
mod::MyGem::Foo
#=> loads "lib/my_gem/foo.rb"
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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"
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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"
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Im is compatible with Zeitwerk
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実装
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# lib/zeitwerk/loader/config.rb
unless real_mod_name(namespace)
raise Zeitwerk::Error,
"root namespaces cannot be anonymous"
end
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# lib/zeitwerk/loader/config.rb
unless real_mod_name(namespace)
raise Zeitwerk::Error,
"root namespaces cannot be anonymous"
end
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# lib/zeitwerk/loader.rb
module Zeitwerk
class Loader
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# lib/im/loader.rb
module Im
class Loader < Module
root of the universe
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loader::Foo loader::Baz
loader::Foo::Bar
loader::Foo::Qux
loader
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# lib/my_gem.rb (main file)
require "zeitwerk"
loader = Zeitwerk::Loader.for_gem
loader.setup # ready!
module MyGem
# ...
end
loader.eager_load # optionally
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# 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!
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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
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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
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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
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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
🙈
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- assert A::X
- assert B::X
+ assert loader::A::X
+ assert loader::B::X
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...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
....................................
Finished tests in 2.968770s, 131.3675 tests/s, 319.6610
assertions/s.
390 tests, 949 assertions, 0 failures, 0 errors, 0 skips
🎉
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The cpath problem
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def cpath(parent, cname)
"#{parent.name}::#{cname}"
end
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def cpath(parent, cname)
"#{parent.name}::#{cname}"
end
Foo :Bar
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def cpath(parent, cname)
"#{parent.name}::#{cname}"
end
Foo :Bar
#=> "Foo::Bar" cpath
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{
"Foo" ⇨ <#Zeitwerk::Loader>,
"Foo::Bar" ⇨ <#Zeitwerk::Loader>,
# ...
}
cpath
Zeitwerk
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{
"<#Im::Loader>::Foo" ⇨ ...
"<#Im::Loader>::Foo::Bar" ⇨ ...
# ...
}
cpath
Im
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MyFoo = mod::Foo
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temporary permanent
"#<...>::Foo" "MyFoo"
MyFoo = mod::Foo
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{
"<#Im::Loader>::Foo" ⇨ ...
"<#Im::Loader>::Foo::Bar" ⇨ ...
# ...
}
cpaths["MyFoo"] #=> nil
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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
❌
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RUBY
RUBY
3.2
3.2
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Foo::BAR = 42
Foo.const_added(:BAR)
callback
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MyFoo = mod::Foo
Object.const_added(:MyFoo)
callback
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module Im::ModuleConstAdded
def const_added(const_name)
# ...
::Im::ExplicitNamespace.__update_cpaths(
prefix, "#{cpath}::#{const_name}"
)
super
end
end
::Module.prepend(Im::ModuleConstAdded)
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module Im::ModuleConstAdded
def const_added(const_name)
# ...
::Im::ExplicitNamespace.__update_cpaths(
prefix, "#{cpath}::#{const_name}"
)
super
end
end
::Module.prepend(Im::ModuleConstAdded)
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{
"<#Im::Loader ...>" ⇨ ...
"<#Im::Loader ...>::Foo" ⇨ ...
"<#Im::Loader ...>::Foo::Bar" ⇨ ...
...
}
cpath
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{
"<#Im::Loader ...>" ⇨ ...
"MyFoo" ⇨ ...
"MyFoo::Bar" ⇨ ...
...
}
cpath
Object.const_added(:MyFoo)
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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
✅
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gem "im", "~> 0.2.2"
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Chris Salzberg
@shioyama github:shioyama/im
github:shioyama/rails_on_im