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kateinoigakukunkateinoigakukun
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Add JSValueDecoder
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Diff for: ‎Sources/JavaScriptKit/JSValueConstructible.swift

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public protocol JSValueConstructible {
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static func construct(from value: JSValue) -> Self?
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}
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extension Bool: JSValueConstructible {
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public static func construct(from value: JSValue) -> Bool? {
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value.boolean
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}
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}
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extension String: JSValueConstructible {
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public static func construct(from value: JSValue) -> String? {
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value.string
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}
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}
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extension Double: JSValueConstructible {
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public static func construct(from value: JSValue) -> Double? {
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guard let rawNumber: Int32 = value.number else { return nil }
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return Double(bitPattern: UInt64(bitPattern: Int64(rawNumber)))
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}
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}
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extension Float: JSValueConstructible {
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public static func construct(from value: JSValue) -> Float? {
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guard let rawNumber: Int32 = value.number else { return nil }
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return Float(bitPattern: UInt32(bitPattern: rawNumber))
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}
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}
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extension Int: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension Int8: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension Int16: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension Int32: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number
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}
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}
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extension Int64: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension UInt: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension UInt8: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension UInt16: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension UInt32: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}
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extension UInt64: JSValueConstructible {
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public static func construct(from value: JSValue) -> Self? {
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value.number.map(Self.init)
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}
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}

Diff for: ‎Sources/JavaScriptKit/JSValueDecoder.swift

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private struct _Decoder: Decoder {
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fileprivate let node: JSValue
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init(referencing node: JSValue, userInfo: [CodingUserInfoKey: Any], codingPath: [CodingKey] = []) {
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self.node = node
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self.userInfo = userInfo
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self.codingPath = codingPath
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}
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let codingPath: [CodingKey]
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let userInfo: [CodingUserInfoKey : Any]
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func container<Key>(keyedBy type: Key.Type) throws -> KeyedDecodingContainer<Key> where Key : CodingKey {
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guard let ref = node.object else { throw _typeMismatch(at: codingPath, JSObjectRef.self, reality: node) }
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return KeyedDecodingContainer(_KeyedDecodingContainer(decoder: self, ref: ref))
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}
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func unkeyedContainer() throws -> UnkeyedDecodingContainer {
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guard let ref = node.object else { throw _typeMismatch(at: codingPath, JSObjectRef.self, reality: node) }
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return _UnkeyedDecodingContainer(decoder: self, ref: ref)
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}
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func singleValueContainer() throws -> SingleValueDecodingContainer {
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self
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}
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func decoder(referencing node: JSValue, with key: CodingKey) -> _Decoder {
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_Decoder(referencing: node, userInfo: userInfo, codingPath: codingPath + [key])
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}
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func superDecoder(referencing node: JSValue) -> _Decoder {
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_Decoder(referencing: node, userInfo: userInfo, codingPath: codingPath.dropLast())
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}
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}
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private enum Object {
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static let ref = JSObjectRef.global.get("Object").object!
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static func keys(_ object: JSObjectRef) -> [String] {
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let keysFn = ref.get("keys").function!
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let keys = keysFn(object).array!
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return keys.map { $0.string! }
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}
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}
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private func _keyNotFound(at codingPath: [CodingKey], _ key: CodingKey) -> DecodingError {
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let description = "No value associated with key \(key) (\"\(key.stringValue)\")."
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let context = DecodingError.Context(codingPath: codingPath, debugDescription: description)
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return .keyNotFound(key, context)
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}
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private func _typeMismatch(at codingPath: [CodingKey], _ type: Any.Type, reality: Any) -> DecodingError {
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let description = "Expected to decode \(type) but found \(reality) instead."
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let context = DecodingError.Context(codingPath: codingPath, debugDescription: description)
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return .typeMismatch(type, context)
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}
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struct _JSCodingKey: CodingKey {
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var stringValue: String
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var intValue: Int?
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init?(stringValue: String) {
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self.stringValue = stringValue
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self.intValue = nil
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}
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init?(intValue: Int) {
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self.stringValue = "\(intValue)"
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self.intValue = intValue
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}
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init(index: Int) {
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self.stringValue = "Index \(index)"
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self.intValue = index
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}
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static let `super` = _JSCodingKey(stringValue: "super")!
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}
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private struct _KeyedDecodingContainer<Key: CodingKey>: KeyedDecodingContainerProtocol {
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private let decoder: _Decoder
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private let ref: JSObjectRef
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var codingPath: [CodingKey] { return decoder.codingPath }
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var allKeys: [Key] {
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Object.keys(ref).compactMap(Key.init(stringValue: ))
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}
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init(decoder: _Decoder, ref: JSObjectRef) {
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self.decoder = decoder
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self.ref = ref
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}
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func _decode(forKey key: CodingKey) throws -> JSValue {
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let result = ref.get(key.stringValue)
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guard !result.isUndefined else {
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throw _keyNotFound(at: codingPath, key)
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}
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return result
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}
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func _throwTypeMismatchIfNil<T>(forKey key: CodingKey, _ transform: (JSValue) -> T?) throws -> T {
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let jsValue = try _decode(forKey: key)
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guard let value = transform(jsValue) else {
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throw _typeMismatch(at: codingPath, T.self, reality: jsValue)
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}
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return value
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}
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func contains(_ key: Key) -> Bool {
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!ref.get(key.stringValue).isUndefined
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}
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func decodeNil(forKey key: Key) throws -> Bool {
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try _decode(forKey: key).isNull
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}
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func decode<T>(_ type: T.Type, forKey key: Key) throws -> T where T: JSValueConstructible & Decodable {
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return try _throwTypeMismatchIfNil(forKey: key) { T.construct(from: $0) }
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}
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func decode<T>(_ type: T.Type, forKey key: Key) throws -> T where T : Decodable {
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return try T(from: _decoder(forKey: key))
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}
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func nestedContainer<NestedKey>(keyedBy type: NestedKey.Type, forKey key: Key) throws -> KeyedDecodingContainer<NestedKey> where NestedKey : CodingKey {
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try _decoder(forKey: key).container(keyedBy: NestedKey.self)
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}
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func nestedUnkeyedContainer(forKey key: Key) throws -> UnkeyedDecodingContainer {
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try _decoder(forKey: key).unkeyedContainer()
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}
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func superDecoder() throws -> Decoder {
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try _decoder(forKey: _JSCodingKey.super)
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}
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func superDecoder(forKey key: Key) throws -> Decoder {
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try _decoder(forKey: key)
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}
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func _decoder(forKey key: CodingKey) throws -> Decoder {
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let value = try _decode(forKey: key)
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return decoder.decoder(referencing: value, with: key)
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}
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}
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private struct _UnkeyedDecodingContainer: UnkeyedDecodingContainer {
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var codingPath: [CodingKey] { decoder.codingPath }
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let count: Int?
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var isAtEnd: Bool { currentIndex >= count ?? 0 }
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var currentIndex: Int = 0
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private var currentKey: CodingKey { return _JSCodingKey(index: currentIndex) }
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let decoder: _Decoder
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let ref: JSObjectRef
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init(decoder: _Decoder, ref: JSObjectRef) {
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self.decoder = decoder
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self.count = ref.length.number.map(Int.init)
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self.ref = ref
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}
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mutating func _currentValue() -> JSValue {
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defer { currentIndex += 1 }
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return ref.get(currentIndex)
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}
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mutating func _throwTypeMismatchIfNil<T>(_ transform: (JSValue) -> T?) throws -> T {
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let value = _currentValue()
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guard let jsValue = transform(value) else {
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throw _typeMismatch(at: codingPath, T.self, reality: value)
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}
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return jsValue
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}
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mutating func decodeNil() throws -> Bool {
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return _currentValue().isNull
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}
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mutating func decode<T>(_ type: T.Type) throws -> T where T: JSValueConstructible & Decodable {
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try _throwTypeMismatchIfNil { T.construct(from: $0) }
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}
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mutating func decode<T>(_ type: T.Type) throws -> T where T : Decodable {
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return try T(from: _decoder())
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}
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mutating func nestedContainer<NestedKey>(keyedBy type: NestedKey.Type) throws -> KeyedDecodingContainer<NestedKey> where NestedKey : CodingKey {
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return try _decoder().container(keyedBy: NestedKey.self)
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}
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mutating func nestedUnkeyedContainer() throws -> UnkeyedDecodingContainer {
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return try _decoder().unkeyedContainer()
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}
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mutating func superDecoder() throws -> Decoder {
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_decoder()
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}
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mutating func _decoder() -> Decoder {
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decoder.decoder(referencing: _currentValue(), with: currentKey)
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}
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}
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extension _Decoder: SingleValueDecodingContainer {
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func _throwTypeMismatchIfNil<T>(_ transform: (JSValue) -> T?) throws -> T {
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guard let jsValue = transform(node) else {
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throw _typeMismatch(at: codingPath, T.self, reality: node)
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}
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return jsValue
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}
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func decodeNil() -> Bool {
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node.isNull
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}
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func decode<T>(_ type: T.Type) throws -> T where T: JSValueConstructible & Decodable {
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try _throwTypeMismatchIfNil { T.construct(from: $0) }
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}
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func decode<T>(_ type: T.Type) throws -> T where T : Decodable {
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let primitive = { (node: JSValue) -> T? in
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guard let constructibleType = type as? JSValueConstructible.Type else {
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return nil
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}
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return constructibleType.construct(from: node) as? T
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}
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return try primitive(node) ?? type.init(from: self)
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}
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}
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public class JSValueDecoder {
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public init() {}
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public func decode<T>(
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_ type: T.Type = T.self,
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from value: JSValue,
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userInfo: [CodingUserInfoKey: Any] = [:]
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) throws -> T where T: Decodable {
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let decoder = _Decoder(referencing: value, userInfo: userInfo)
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return try T(from: decoder)
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}
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}

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