Re: エラーと警告でコードをデザインする

Transcript

1. 1.

   Re: ΤϥʔͱܯࠂͰ ίʔυΛσβΠϯ͢Δ 2017/3/22 ezura

2. 2.

   ςετ ։ൃମ੍ɾ؀ڥ ઃܭࢥ૝ɾཧ࿦ ݴޠʹΑΔ
 αϙʔτ j j j j ϜϲεϮϥ΀ᩆ౰ᕥ

3. 3.

   https://speakerdeck.com/ezura/eratojing-gao-de-kodowodezainsuru-chi- tohuang-falselun-wu-qu ΤϥʔͱܯࠂͰίʔυΛσβΠϯ͢Δ NFUIPE
   ΀Ṻ΅ᲇͩᘡᔀ͞ᩆ͖ͩͥͺΤ
 θϸϖΩϰᙉͽݕᒕͫΝ

4. 4.

   લఏ struct Object { var name: String var something: Any

   func common() { /* do something */ } func method1() { /* do something */ } func method2() { /* do something */ } }
5. 5.

   method1 Λ࣮ߦ͔ͯ͠ΒͷΈ
 method2 Λ࣮ߦՄೳ (ҧ൓ΛίϯύΠϧ࣌ʹݕ஌) Mission1 // OK object.method1().method2() //

   Error object.method2()
6. 6.

   method1, method2 Λ࣮ߦޙͷ
 ΠϯελϯεͷΈҾ਺ͱͯ͠ड͚औΔؔ਺ (ҧ൓ΛίϯύΠϧ࣌ʹݕ஌) Mission2 // OK accept(object.method1().method2()) //

   Error accept(object.method2())
7. 7.

   ࣮૷

8. 8.

   ࣮૷ͷ֓೦ਤ instance Init state instance State1 instance State2 func method1

   func method2
9. 9.

   struct Object<State> { var name: String var something: Any func

   common() { /* do something */ } }
10. 10.

    extension Object where State: Init { func method1() -> Object<State1>

    { /* do something */ } } extension Object where State: State1 { func method2() -> Object<State2> { /* do something */ } } func accept(_ object: Object<State2>) { /* do something */ }
11. 11.

    ࣮૷ͷ֓೦ਤ instance Init state instance State1 instance State2 func method1

    func method2 Object<Init> Object<State1> Object<State2>
12. 12.

    ཧ࿦͸Θ͔ͬͨʂ ࣮૷ʹམͱ͠ࠐΜͰΈΑ͏

13. 13.

    extension Object where State: Init { func method1() -> Object<State2>

    { let object = Object<State2>(…) // Object ͷϓϩύςΟΛҾ͖ܧ͗ return object } }
14. 14.

    ܕύϥϝʔλ͕ҧ͏Πϯελϯε
 (= ҟͳΔܕ)
 ͷؒͰͲ͏΍ͬͯσʔλΛҾ͖ܧ͝͏…

15. 15.

    Object<Init> ͔Β Object<State1> ΁
 σʔλΛҾ͖ܧ͙ʹ͸ʁʁ new.name = self.name new.something =

    self.something struct Container { var name: String var something: Any }
16. 16.

    ΩϟετͰ͖ΔΑʂ ۽୩͞Μ

17. 17.

    Object<Init> ͔Β Object<State1> ΁ extension Object where State: Init {

    func method1() -> Object<State2> { let object = unsafeBitCast(self, to: Object<State2>.self) // do something return object } } Object<Init> ͔Β Object<State1> ΁ Cast
18. 18.

    ࣮૷Ͱ͖ͨʂ ࢖͍উख͸Ͳ͏͔ͳʁʁ

19. 19.

    let object = Object<Init>(name: "sample", something: "something") <Init> ͷ໌͕ࣔඞཁ…
 (´ɾωɾʆ)

20. 20.

    ίϯύΠϥʹ఻͑ͯΈΑ͏

21. 21.

    extension Object where State: Init { init(name: String, something: Any)

    { self.name = name self.something = something } } State ͕ Init ͷͱ͖ͷΈ
 ίϯετϥΫλΛએݴ
22. 22.

    let object = Object(name: "sample", something: "something") <Init> ͷ໌͕ࣔෆཁ ஫:

    ͜Ε͕ՄೳͱͳΔ৚͕݅͋Γ·ׂ͕͢Ѫ͠·͢
 (৚͕݅ἧ͍ͬͯͳ͍৔߹ɺίϯύΠϧΤϥʔ)
23. 23.

    ͱͬͯ΋៉ྷʹͳΓ·ͨ͠ʂʂ
 ٩( 'ω' )و

24. 24.

    https://gist.github.com/ezura/ e71db2b0471285061f9700809f92f2b1 ίʔυ

25. 25.

    ࢀর • ۽୩ͱ៸໘͕ϓϩάϥϛϯάίʔυͷ಺͔Βௌ͑ͯ͘͜ Δ੠ʹࣖΛ܏ָ͚ͯ͠ΉϥδΦ #9, #14
 http://mookmookradio.com/a0005/ • where Ͱͷܕਪ࿦ͷఏএऀͷํͷ

    gist
 https://gist.github.com/tarunon/ d7071689ab55e29bd367a44833687aa3 • ΤϥʔͱܯࠂͰίʔυΛσβΠϯ͢Δ
 https://speakerdeck.com/ezura/eratojing-gao-de- kodowodezainsuru-chi-tohuang-falselun-wu-qu