ecmascript-proposal-first-class-protocol

EcmascriptのFirst class protocolの提案について

Transcript

1. proposal-first-class-protocol
   

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2. せ⵸: @brn (ꫬꅿ⨳ⵃa.k.a ـٕ٦ظ)
   耵噟: ؿٗٝزؒٝسؒٝآص،٥iOSؒٝآص،
   ⠓爡: Cyberagent ،سذؙأةآؔRightSegment٥AI Messenger
   ـؚٗ: http://abcdef.gets.b6n.ch/
   Twitter: https://twitter.com/brn227
   GitHub: https://github.com/brn
   

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3. What is this proposal ?
   protocolך䲿周
   ⯋ղכinterfaceך䲿周׌׏׋կ
   

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4. What is 'protocol' ?
   classָ㹋鄲ׅץֹ鋉秈׾邌ׅկ
   㹋䡾כקה׿וinterfaceהずׄדծ
   swiftװobjective-cדכinterface׾protocolהㄎןծ
   javaדכず瘝ך׮ך׾interfaceהㄎע(稢ְַ鎉铂➬圫♳ך麩ְכ֮
   ׷ָ)
   

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5. Ecmascript way
   ׃ַ׃Ecmascriptךprotocolכֿך⚕倯ה׮殯ז׷杝荈ך➬圫ָ䲿
   周ׁ׸גְ׷կ
   

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6. As Symbol
   植㖈䲿周⚥ךֿךproposalכprotocol׾ծ
   ًاحس׾䭯אSymbolך꧊さה׃ג邌ׅկ
   

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7. protocol ProtocolName {!
   // 実装が必要なシンボルを宣言
   thisMustBeImplemented;!
   !
   // メソッド実装
   youGetThisMethodForFree() {!
   return this[ProtocolName.thisMustBeImplemented]();!
   }!
   }!
   !
   class ClassName implements ProtocolName {!
   [ProtocolName.thisMustBeImplemented]() {!
   ...!
   }!
   } !
   

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8. Extends Existing class
   傀㶷ךclassח㼎׃ג׮protocol׾㹋鄲ׅ׷ֿהָדֹ׷կ
   

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9. protocol Functor {!
   map;!
   }!
   !
   Promise.prototype[Functor.map] = () => {!
   ...!
   }!
   !
   Protocol.implement(Promise, Functor);!
   

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10. 'implements' keyword
    倜׋חimplements怴皾㶨ָ鷄⸇ׁ׸׷
    

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11. Promise implements Functor // true!
    !
    if (MyClass implements SomeProtocol) { }!
    

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12. Extends protocol
    protocolכ➭ךprotocol׾䭁䓸דֹ׷
    

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13. protocol A { a; }!
    protocol B extends A { b; }!
    !
    class C implements B {!
    [A.a]() {}!
    [B.b]() {}!
    }!
    !
    class D implements A {!
    [A.a]() {}!
    }!
    

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14. Default
    Implementation
    ⴱ劍㹋鄲׮鷄⸇דֹ׷
    

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15. protocol A { a; }!
    !
    protocol B extends A {!
    [A.a]() { ... }!
    }!
    

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16. Static protocol
    ꫼涸ًاحس׮protocolדⵖ䖴ׅ׷ֿהָ〳腉
    

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17. protocol A {!
    static b() {}!
    }!
    !
    class C implements A { }!
    C[A.b]();!
    

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18. Issues
    傀㶷ךؙٓأ׾䭁䓸ׅ׷㜥さծprototypeפך湫䱸➿Ⰵהְֲ䲿周ָ
    遤׻׸גְ׷կ
    ְֻ׵ז׿ד׮儗➿鹼׸זךדծ➿剏周׾䲿周׃גְֶ׋կ
    

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19. Proposed 1
    Protocol.impelemtꟼ侧ך痥♲䒷侧ד㹋鄲
    

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20. protocol Functor {!
    map;!
    }!
    !
    // If implementation is not satisfied,
    throw TypeError.!
    Protocol.implement(Array, Functor, {!
    [Functor.map]: Array.prototype.map!
    });!
    

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21. Proposed 2
    傀㶷ךؙٓأ׮ⱄ䏝implementsؗ٦ٙ٦سד䭁䓸〳腉ח
    

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22. protocol Functor {!
    map;!
    }!
    !
    // We can implements protocol after
    declaration.!
    Array implements Functor {!
    [Functor.map]: Array.prototype.map!
    }!
    

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23. TypeScript?
    ה׶ִ֮׆ծ傀㶷ךinterfaceכ婍ׅד֮׹ֲהךֿהկ
    protocol׾וך״ֲז㘗ה׃ג䪔ֲַכ劢㹀
    Allow dynamic name in typesהְֲ㘗ךفٗػذ؍せחsymbol׾
    ⢪ֲֿהָדֹ׷PRָ鹌׿דְ׷ךדծ
    ֿ׸ָ㹋鄲ׁ׸׷הprotocol׮أي٦ؤחְֽ׷ַ׮կ
    

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24. ׀幠耮֮׶ָהֲ׀ְׂת׃׋
    

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