Slide 1
Slide 1 text
Re: ΤϥʔͱܯࠂͰ
ίʔυΛσβΠϯ͢Δ
2017/3/22
ezura
Slide 2
Slide 2 text
ςετ
։ൃମ੍ɾڥ
ઃܭࢥɾཧ
ݴޠʹΑΔ
αϙʔτ
j
j
j
j
ϜϲεϮϥᩆᕥ
Slide 3
Slide 3 text
https://speakerdeck.com/ezura/eratojing-gao-de-kodowodezainsuru-chi-
tohuang-falselun-wu-qu
ΤϥʔͱܯࠂͰίʔυΛσβΠϯ͢Δ
NFUIPEṺ΅ᲇͩᘡᔀ͞ᩆ͖ͩͥͺΤ
θϸϖΩϰᙉͽݕᒕͫΝ
Slide 4
Slide 4 text
લఏ
struct Object {
var name: String
var something: Any
func common() { /* do something */ }
func method1() { /* do something */ }
func method2() { /* do something */ }
}
Slide 5
Slide 5 text
method1 Λ࣮ߦ͔ͯ͠ΒͷΈ
method2 Λ࣮ߦՄೳ
(ҧΛίϯύΠϧ࣌ʹݕ)
Mission1
// OK
object.method1().method2()
// Error
object.method2()
Slide 6
Slide 6 text
method1, method2 Λ࣮ߦޙͷ
ΠϯελϯεͷΈҾͱͯ͠ड͚औΔؔ
(ҧΛίϯύΠϧ࣌ʹݕ)
Mission2
// OK
accept(object.method1().method2())
// Error
accept(object.method2())
Slide 7
Slide 7 text
࣮
Slide 8
Slide 8 text
࣮ͷ֓೦ਤ
instance
Init state
instance
State1
instance
State2
func
method1
func
method2
Slide 9
Slide 9 text
struct Object {
var name: String
var something: Any
func common() { /* do something */ }
}
Slide 10
Slide 10 text
extension Object where State: Init {
func method1() -> Object { /* do something */ }
}
extension Object where State: State1 {
func method2() -> Object { /* do something */ }
}
func accept(_ object: Object) { /* do something */ }
Slide 11
Slide 11 text
࣮ͷ֓೦ਤ
instance
Init state
instance
State1
instance
State2
func
method1
func
method2
Object Object Object
Slide 12
Slide 12 text
ཧΘ͔ͬͨʂ
࣮ʹམͱ͠ࠐΜͰΈΑ͏
Slide 13
Slide 13 text
extension Object where State: Init {
func method1() -> Object {
let object = Object(…)
// Object ͷϓϩύςΟΛҾ͖ܧ͗
return object
}
}
Slide 14
Slide 14 text
ܕύϥϝʔλ͕ҧ͏Πϯελϯε
(= ҟͳΔܕ)
ͷؒͰͲ͏ͬͯσʔλΛҾ͖ܧ͝͏…
Slide 15
Slide 15 text
Object ͔Β Object
σʔλΛҾ͖ܧ͙ʹʁʁ
new.name = self.name
new.something = self.something
struct Container {
var name: String
var something: Any
}
Slide 16
Slide 16 text
ΩϟετͰ͖ΔΑʂ
۽୩͞Μ
Slide 17
Slide 17 text
Object ͔Β Object
extension Object where State: Init {
func method1() -> Object {
let object = unsafeBitCast(self,
to: Object.self)
// do something
return object
}
} Object ͔Β
Object Cast
Slide 18
Slide 18 text
࣮Ͱ͖ͨʂ
͍উखͲ͏͔ͳʁʁ
Slide 19
Slide 19 text
let object = Object(name: "sample", something: "something")
ͷ໌͕ࣔඞཁ…
(´ɾωɾʆ)
Slide 20
Slide 20 text
ίϯύΠϥʹ͑ͯΈΑ͏
Slide 21
Slide 21 text
extension Object where State: Init {
init(name: String, something: Any) {
self.name = name
self.something = something
}
}
State ͕ Init ͷͱ͖ͷΈ
ίϯετϥΫλΛએݴ
Slide 22
Slide 22 text
let object = Object(name: "sample", something: "something")
ͷ໌͕ࣔෆཁ
: ͜Ε͕ՄೳͱͳΔ͕݅͋Γ·ׂ͕͢Ѫ͠·͢
(͕݅ἧ͍ͬͯͳ͍߹ɺίϯύΠϧΤϥʔ)
Slide 23
Slide 23 text
ͱͬͯ៉ྷʹͳΓ·ͨ͠ʂʂ
٩( 'ω' )و
Slide 24
Slide 24 text
https://gist.github.com/ezura/
e71db2b0471285061f9700809f92f2b1
ίʔυ
Slide 25
Slide 25 text
ࢀর
• ۽୩ͱ៸໘͕ϓϩάϥϛϯάίʔυͷ͔Βௌ͑ͯ͘͜
ΔʹࣖΛָ͚ͯ͠ΉϥδΦ #9, #14
http://mookmookradio.com/a0005/
• where Ͱͷܕਪͷఏএऀͷํͷ gist
https://gist.github.com/tarunon/
d7071689ab55e29bd367a44833687aa3
• ΤϥʔͱܯࠂͰίʔυΛσβΠϯ͢Δ
https://speakerdeck.com/ezura/eratojing-gao-de-
kodowodezainsuru-chi-tohuang-falselun-wu-qu