FunctionBuilderでコンパイラを表現しようとした

FunctionBuilderでコンパイラを表現しようとしたけど、できなかったしユースケースも違った話

Transcript

1. FunctionBuilderͰίϯ ύΠϥΛදݱ͠Α͏ͱͨ͠ Yumemi.inc Αͬ͠ʔɹ
2. ࣗݾ঺հ ΏΊΈiOSΤϯδχΞ 24ࡀ SwiftUIͱxPlatʹڵຯਂʑ Vue.js/node.js/CS @seijin4486
3. SwiftUI͔ͬͨ͢͝ ׬શʹDSLʁ͔ͱࢥ͍͖΍ɺSwiftͷྗΛੜ͔͠ ੾ͬͨه๏ implict return/property wrapper/function builder UIKitͰഓͬͨܦݧ͕ແʹؼ͢͜ͱ͸શ෦๨ΕͯiOS ΤϯδχΞ྆खͰສࡀ(΋ͪΖΜUIKitͷ஌ݟ͸ࠓޙ ΋ੜ͖Δ͸ͣ
4. ࠓ΍ͬͯΔ΋ͷ ίϯϐϡʔλʔγεςϜͷཧ ࿦ͱ࣮૷ VM͔ΒΞηϯϒϥม׵͢Δ ͱ͜ΖͰ࢖͑ͳ͍͔ͳ…ɻ
5. ͜͏ॻ͚ͨΒؾ࣋ͪྑ͍ͷͰ͸ʂ var body: some VMCommand { Function(name: “mult”) {
 Push(.constant, 0) Pop(.local, 0) Push(.argument, 1) Pop(.local, 1) Label(“LOOP”)
 …. Label(“END”) Return }
 ɹ… } var commands: [Command] = []
 func build() -> String { commands.append(Push(.constant, 0)) commands.append(Pop(.argument, 1)) commands.append(Pop(.local, 1)) commands.append(Label(“Loop”)) return commands .map { $0.generate() }
 .joined(separator: “\n”) } ݱঢ় FunctionBuilder΁ͷظ଴
6. ΍ͬͯΈΑ͏ʂ
7. Ͱ͖ͳ͔ͬͨ
8. Ұ෦ɺͰ͖ͳ͔ͬͨ TupleViewͷΑ͏ͳ࢓૊ΈΛ࢖ͬͯ΋ɺ࣮ࡍʹbody ͷπϦʔΛߏங͢Δ࢓૊Έ͕෼͔Βͳ͔ͬͨ SwiftUIͰHTMLͷඳըΛ͢ΔϓϩδΣΫτΛݟͨ ͕ɺMirror΍࠶ىॲཧΛ࢖ͬͯؤுͬͯΔ ៉ྷͳղܾ๏͸ఘΊͯɺҰ୴͜Μͳܗʹͨ͠
9. FunctionBuilder @_functionBuilder struct CommandBuilder { public static func buildBlock<Content>(_ content: Content) -> String where Content: Command { content.body } public static func buildBlock<T1, T2>(_ t1: T1, _ t2: T2) -> String where T1: Command, T2: Command { [t1.body, t2.body] .joined(separator: "\n") } struct TupleCommand<T>ͷར༻͸ఘΊͨ protocol Command { var body: String { get } } struct AssemblyCommand: Command { var body: String init(@CommandBuilder builder: () -> String) { body = builder() } }
10. ͜͏ॻ͚ΔΑ͏ʹͳΓ·ͨ͠ struct Add: Command { var body: String { AssemblyCommand { A.symbol(.sp) C.assign(destination: .am, computation: .mMinusOne) C.assign(destination: .d, computation: .m) C.assign(destination: .a, computation: .aMinusOne) C.assign(destination: .m, computation: .dPlusM) }.body } }
11. ίϯύΠϧ࣌ & ৘ใ͚ͭͨ͠ struct Add: Command { var body: String { AssemblyCommand { () -> String in … ᶃ CommandBuilder.buildBlock( … ᶄ A.symbol(.sp), C.assign(destination: .am, computation: .mMinusOne), C.assign(destination: .d, computation: .m), C.assign(destination: .a, computation: .aMinusOne), C.assign(destination: .m, computation: .dPlusM)
 ) }.body } } @_functionBuilder struct CommandBuilder { public static func buildBlock<T1, T2>(_ t1: T1, _ t2: T2) -> String where T1: Command, T2: Command { [t1.body, t2.body] .joined(separator: "\n") } ᶃ ΫϩʔδϟͷฦΓ஋ ᶄ CommandBuilder
12. ৮ͬͯΈͨײ૝ ࢹ֮తͳཧղ༻ҙੑ্͕͕Δ(Έ΍͍͢) buildBlock͸gybͰੜ੒͞Εͯͦ͏ TupleViewΛͲ͏࢖ͬͯΔ͔஌Γ͍ͨ Ϣʔεέʔε͕ҧͬͨ
13. Ϣʔεέʔε͕ҧͬͨ…ͳͥʁ SwiftUI͸ɺ։ൃऀ͕ࣗ༝ʹViewStackΛ૊ΊΔ struct MyGroupView : View { var category: String var categorizedItems: [Item] var body: some View { VStack(alignment: .leading, spacing: 10) { Text(category) .padding(.top, 10) .padding(.leading, 8) .background(Color.green) .cornerRadius(5) .padding(5) Group { ForEach(categorizedItems) { item in ListRow(item: item) } } } .padding(.bottom, 10) } }
14. Ϣʔεέʔε͕ҧͬͨ…ͳͥʁ Push, Pop, Call, FunctionͳͲ͸ɺVMΛ෼ׂ/ύʔε͠ ͨ಺༰ʹґଘͯ͠ߏங͢ΔͷͰɺ։ൃऀࣗ਎͕ߏ ங͢Δߏ଄͕΄΅ଘࡏ͠ͳ͍ ϝϦοτ΄΅ͳ͍ VMهड़DSLͱͯ͠FunctionBuilderΛ༻͍ΔͳΒ…
 ΞϦ(?)
15. ·ͱΊ Apple͕ViewBuilderͰ࡞ͬͨ಺༰ΛͲ͏ඳը͍ͤͯ͞Δͷ ͔෼͔Βͳ͍ɻ஌Γ͍ͨ ViewBuilderΛ࢖͏ͱɺ͘͢͝ݟ΍͘͢ॻ͚Δࣄ͕෼͔ͬͨ ΤϯδχΞଆ͕ߏ଄Λࣗ༝ʹهड़͢ΔέʔεͰ͸ɺઈେ ͳޮՌΛൃش͢Δɻ ࠓճͷόοΫΤϯυίϯύΠϥͰ࢖ͬͯΈΔࢼΈ͸ࣦഊ Ͱ΋៉ྷʹ͸ݟ͑Δ