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Ruby
ܕผᒾҰ۩؆հ
John Lin (@johnlinvc)
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᮫ԙզ
• John Lin
• تᓣ Ruby & Swiftɻओ㭎Swift Taipei Meetupɻ
• Twitter: @johnlinvc
• Blog: https://johnlin.vc/
• Principle Solution Architect @ West Pharmaceutical
Service (ࣜဌऱ)
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ڧྗ㐸࠽த
• ओཁੋ၏ᬭྍᢛۀ IoT ɻूᅶᚙలॏ৺೭Ұɻ
• google "cake resume west"ɼ༗ෟࢿൣᅴɻ
• ཤ㑖త࣌㘸ੋ John Lin հతɻိత referral bonus
㟬Ұɻ
• Coscup ᩶ॿ
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Agenda
• Ruby తܕผܥ౷
• ܕผᒾҰత႔
• Ruby ܕผᒾҰ۩తಛ৭
• Sorbet
• Steep
• ൺֱ Ruby తܕผᒾҰ۩
• Q&A
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Ruby తܕผܥ౷
• ڧܕผ Strong Type
• ಈଶܕผ Dynamic Type
• יࢠܕผ Duck typing
• ॴ༗౦ੋ݅ Everything is object
• ᄸҰঝ Single Inheritance
• Mixin
• nil
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ܕผᒾҰత႔
• ᒾҰଧࣈࡨޡ
• ᒾҰჩᏐၚᬇࡨޡ
• ఏߴఔࣜᛰతՄᯪੑ
• ՄҎॱศఏڙఔࣜᛰతࢿ㘤څ IDEɻ
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Ruby ܕผᒾҰ۩తڞಉಛ৭
• ᔒ༗ํతܕผᒾҰ۩
• ਐࣜܕผᒾҰ Gradual type checker.
• ܕผఆٛ䈕 Type def
fi
les
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ᔒ༗ํతܕผᒾҰ۩
• ᔒ༗ํతܕผᒾҰ۩ɻ
• ୠੋ༗ํతܕผඪɼRuby Signature (RBS) ɻ
• Python & javascript ੋҰᒬɻ
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RBS ܕผఆٛ䈕
• Ruby ํతܕผఆٛ֨ࣜɻ
• ᘐཱ䈕Ҋɻ
• ՄҎኺݪ࢝ᛰࣗಈ㗞ੜൣຊɻ
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ਐࣜܕผᒾҰ
Gradual Type Check
• ՄҎᒾҰ෦తఔࣜᛰɻ
• ߱ಋೖɻ
• Python(mypy) & TypeScript ੋɻ
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ܕผఆٛ䈕
• ᘐཱత䈕Ҋɻ
• ఆٛྃܕผɼৗᏐɼํ๏ɼݸᱪᏓᏐతܕผɻ
•
class Foo
def bar(s); end
end
class Foo
def bar: (s: String) -> String
end
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ܕผᩄ (type annotation)
• ࡏఔࣜᛰதՃ্Ḽղ҃ੋֹ֎తඪࣔɻ
• ૾ੋ C++, Python ҃ Typescript ੋɻ
class Foo
sig{params(s: String).returns(String)}
def bar(s)
end
end
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ܕผఆٛ䈕త༏᠍ᴍ
• ᠍ᴍɿఔࣜܕผఆٛࡏෆಉ䈕ҊɼՄೳ။هվɻ
• ༏ᴍɿఔࣜޠ๏ൺֱᄸ७ɻ
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ܕผఆٛ䈕
V.S. ܕผᩄ (type annotation)
• Matz:
• ఔࣜෆधཁܕผඪࣔब။ಈɻtype annotation ҧྃ
DRY(Don't Repeat Yourself) ݪଇɻ
• ະိՊٕⴺਐ㑊ޙɼ༗Մೳશෆधཁܕผఆٛ䈕ɻ
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Ruby ܕผੳ۩
• Sorbet
• Steep
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Sorbet
• ༝ Stripe ։ᚙɼ༻ C++ & Rubyሜతɻ
• ᯩଶᒾҰ ˍ ಈଶᒾҰ
• 㚎ݐޠݴثڠఆ(Language Server Protocol, LSP)
• ෆಉڃతਐࣜᒾҰ
• ಉ࣌ࢧԉ ܕผᩄ(Type Annotation) ᢛ RBI ܕผఆٛ䈕ɻ
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ᯩଶᒾҰ
• ࣥߦsorbet ိᒾҰܕผɼෆधཁਅతࣥߦఔࣜɻ
• ༻ڥɿሜఔࣜதɼ lsp serverɻ࿈᠃߹(CI)ɻ
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ಈଶᒾҰ
• ࣥߦఔࣜత࣌ީɼSorbet ။ᒾҰܕผฒ㗞ੜࡨޡ҃Log
• ༻ڥɿ࿈᠃߹(CI)தతᄸݩଌࢼ҃߹ଌࢼɻ༬උ
ڥ(Staging)ɻਖ਼ࣜڥɻ
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㚎ݐޠݴثڠఆ
• VSCode ҃ Emacs ࢧԉ ޠݴثڠఆ తฤाث
࣌ɼՄҎଈ࣌ᰖࣔࡨޡɻෆधཁ㠥֎ࣥߦࢦྩɻ
• ఏڙྃ౸ఆٛɼᰖࣔ༻ᴍɼᏓᏐվ໊ޭೳɻ
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ෆಉڃతਐࣜᒾҰ
• ࡏ䈕Ҋ։಄Ճ্ਆحḼղ # typed: LEVEL बՄҎઃఆᒾҰతڃ
• # typed: ignore : શࠌུɼՄҎෆੋ༗Ꮘతఔࣜᛰ
• # typed: false ɿ ᒾҰޠ๏ɼ༬ઃᆴɻ
• # typed: trueɿᒾҰ༗ఆٛతܕผɼ
• # typed: strict :ॴ༗తܕผधཁ༗ఆٛɻ
• # typed: strongɿbug ଟɼෆཁ༻ɻ
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Sorbet ܕผඪࣔ
• ՄҎࡏఔࣜᛰத၏ܕผᩄ
• ՄҎ༻ᘐཱత RBI ܕผఆٛ䈕
• ՄҎಉ࣌༻ɻୠੋෆೳॏෳඪࣔɻ
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ܕผᩄ
• ༻ T:Sig module ိ၏ܕผᩄɻ
• ܕผᩄޙతఔࣜᛰґવੋ߹๏త Ruby ఔࣜᛰɻ
• ՄҎሣᏓᏐ၏ܕผᩄɻ
extend T::Sig
sig{params(n: Integer).returns(Integer)}
def add1(n); n+1; end
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RBI ܕผఆٛ䈕
• ܕผᩄաޙతఔࣜ፤ᎃመ࡞ɼबྃ RBI ܕผఆٛ
䈕ɻ
• ೳሣৗᏐɼํ๏መᱪᏓᏐ၏ܕผඪࣔɻ
extend T::Sig
sig{params(n: Integer).returns(Integer)}
def add1(n); end
def add1(n)
n+1
end
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جຊܕผ
• T.untyped
• Ұൠܕผ
• Boolean
• Array & Hash
• Nilable
• Block & Proc & lambda
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T.untyped
• ᔒ༗څܕผ࣌ީత typeɻ
• BasicObject ʢॴ༗݅తڞಉઌʣ ෆಉɼT.untyped
။શུաܕผᒾҰɻ
• T.untyped => զෆࡏݷ
• BasicObject => զෆಓɻ
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Ұൠܕผ
• 1 => Integer or Numeric
• 3.14 => Float or Numeric
• "hello" => String
• :world => Symbol
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Boolean
• true => T::Boolean or TrueClass
• false => T::Boolean or FalseClass
• T::Boolean => Union(TrueClass ,FalseClass)
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Array & Hash
• [1,2,3] => T::Array[Integer]
• %w{a b c} => T::Array[String]
• {hello: "world"} => T::Hash[Symbol, String]
• {"answer" => 42} => T::Hash[String, Integer]
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T.nilable
• T.nilable(Integer) => Union(NilClass, Integer)
• ENV["RAILS_ENV"] => T.nilable(String)
• debug = T.must(ENV["DEBUG"]) => String
Ռ DEBUG ෆଘࡏɼࣥߦظ။㋝ग़ྫ֎
• debug = ENV.fetch("DEBUG","") => String
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Block & Proc & lambda
• proc {|n| n * 2 } => T.proc.params(n:
Integer).returns(Integer)
• Proc.new{|n| n*2} => Proc
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ಛघܕผ
• ࿆ूܕผ T.any
• ަूܕผ T.all
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࿆ूܕผ T.any
• ՄҎҝଖதҰछܕผ
• T.nilable(X) => T.any(NilClass, X)
sig {params(x: T.any(Integer,String)).void}
def foo(x); end
foo(10)
foo("Hello, world")
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ަूܕผ T.all
• ಉ࣌༗ Module1 & Module2 ၷݸ Mixin
•
{params(x: T.all(Module1, Module2)).void}
def requires_both(x)
x.method1 # ok
x.method2 # also ok
end
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ํ๏ܕผඪࣔ
• ҰൠჩᏐ & ᮫伴ࣈჩᏐ
• ՄᏓჩᏐ
• block ჩᏐ
• Void ճၚᆴ
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ҰൠჩᏐ & ᮫伴ࣈჩᏐ
extend T::Sig
sig{params(n: Integer, s: String).returns(String)}
def foo(n)
"#{n} #{s}"
end
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ՄᏓჩᏐ
• args ҰఆੋArray ॴҎཁඪࣔݩૉతܕผ
• kwargs Ұఆੋ Keyҝ Symbol త Hash, ॴҎཁඪࣔValue
తܕผɻ
extend T::Sig
sig{params(args: Int, kwargs: String).returns(String)}
def foo(*args, **kwargs)
"#{args.sum}" + kwargs.map{|k,v| "#{k}: #{v}"}
end
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block ჩᏐ
• ཁՃ &blk ࠽ೳඪࣔჩᏐతܕผɻᔒՃత block ။ඃᙛ
untyped
sig {params(blk: T.proc.returns(Integer)).returns(Integer)}
def foo(&blk) # <-
yield
end
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Void ճၚᆴ
• Ruby Ӭԕ။ճၚ࠷ޙҰߦɻୠ༗࣌ީੋ䭘䭓ᆴɻ
• ඪ্ void తबՄҎආ໔ޡ༻ճၚᆴɻ
sig {params(name: String).void}
def greet(name)
puts "Hello, #{name}!"
end
puts greet("Coscup") # ERROR !
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ᏓᏐܕผඪࣔ
• T.let
• T.cast
• T.bind
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T.let
• ઃఆᏓᏐత type
• ෆ߹ཧత value ။༗ errorɻ
x = T.let(10, Integer)
y = T.let(10, String) # error
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T.cast
• ՄҎڧ੍ܕଖଞ typeɻ
• ୠؐੋ။ᒾҰ A ౸ఈ༗ᔒ༗ foo ํ๏ɻ
case label
when 'a'
T.cast(a_or_b, A).foo
when 'b'
T.cast(a_or_b, B).bar
end
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T.bind
• self ڧ੍ܕ༻త
• self ෆೳ༻ T.cast
• ࡏ proc/block ཫ໘۰౸ instance_eval ࣌መ༻
T.bind(self, MyClass)
self.method_on_my_class
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fl
ow-sensitive
• Sorbet ಓࡏ if ཫ໘త x ෆՄೳੋ nilɼॴҎෆ။༗ܕผࡨ
ޡɻ
• if/unless, case, nil? , is_a? , ! , &&, || ။աᖤᎃෆՄೳత
ܕผ
x = T.let(1, T.nilable(Integer))
if x
x + 1 # No Error
end
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আࡨޭೳ
• ՄҎ༻ိᰖࣔҰݸᆴ༬ظతܕผɻ
• Ұ։࢝ෆಓܕผత࣌ީ༻ɻ
T.reveal_type(1)
editor.rb:9: Revealed type: Integer(1) https://srb.help/7014
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T.unsafe
• զಓࣗݾࡏ၏ॄኄɻผզɻ
class A
def method_missing(method)
puts "Called #{method}"
end
end
T.unsafe(A.new).foo # => ok
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ਐ֊ܕผఆٛ
• Abstract class & interface
• Sealed class
• Final class
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ҏἾ֥ূ
• ࣥߦ༻త script ཁ༻ if __FILE__ ==
$PROGRAM_NAME แىိɻ
• RSpec ။༗Ұେථ TypeErrorɻՄҎશ෦ ignoreɻ
• ଟ Gem ؐᔒ༗ Type De
fi
nitionɻ၏ग़։ݯߩᘔతେ
࣌ػɻ
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Steep
• by Soutaro Matsumoto ɼ༻ Ruby ሜతɻ
• ํతܕผᒾҰثɼʢҼҝ RBS ੋಉҰݸ࡞ऀʣ
• ᯩଶᒾҰɻ
• ༻ ᘐཱత RBS ܕผఆٛ䈕ɻ
• gem install steep
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Steep
fi
le
target :app do
check "lib"
signature "sig"
library "set", "pathname"
end
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Steep తਐࣜᒾҰ
• ۰౸ᔒ༗ܕผᩄతఔࣜᛰɼ။ᙛ࡞ untyped ိ႔ཧɻ
• untyped త݅။աॴ༗తᒾҰɻ
• ༗ෆᒾҰత䈕ҊՄҎࡏ Steep
fi
le ཫ ignore ᎃɻ
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RBS ܕผఆٛ䈕
class Channel
attr_reader name: String
def initialize: (name: String) -> void
def each_member: () { (User | Bot) -> void } ->
void
# `{` and `}` means block.
| () -> Enumerator[User | Bot,
void]
# Method can be overloaded.
end
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RBI vs RBS
• RBI: ෆՄҎఆٛ typeɼؐՄҎሣܕผ၏ਐ֊ఆٛɻ
• RBS: ՄҎ၏ overloading
• መࡍ্બ䬟ݸՄҎɼ༗۩(parlour) ՄҎ၏ɻ
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֘༻䬟Ұݸʁ
• Sorbet
• ൺֱख़ɼࣕ Stripe ࣗݾ༗ࡏ༻ɻ
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݁
• Ruby ܕผᒾҰثਖ਼ࡏᚙలதɻ
• Sorbet ੋલൺֱख़తᒾҰثɻ
• ݱࡏੋሣ Ruby ܕผᒾҰ࡞ग़ߩᘔతେ࣌ػɻ
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Q&A
• Өยࡏ https://johnlin.vc/
coscup-2022/
• ՄҎࡏ twitter ্ፙ౸զ
@johnlinvc
• ༗ڵझՄҎగ㕕զత blog
https://johnlin.vc
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References
• https://sorbet.org
• https://github.com/soutaro/steep
• https://www.youtube.com/watch?v=2g9R7PUCEXo
• https://www.thestrangeloop.com/2019/typing-the-
untyped-soundness-in-gradual-type-systems.html
• [2] https://github.com/AaronC81/parlour