Added Codable support

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:4.1
+// swift-tools-version:5.0
 import PackageDescription
 
 let package = Package(name: "TLVCoding",
@@ -12,4 +12,4 @@ let package = Package(name: "TLVCoding",
                         .target(name: "TLVCoding", path: "./Sources"),
                         .testTarget(name: "TLVCodingTests", dependencies: ["TLVCoding"])
                         ],
-                      swiftLanguageVersions: [4])
+                      swiftLanguageVersions: [.v5])

Package@swift-4.1.swift

@@ -0,0 +1,15 @@
+// swift-tools-version:4.1
+import PackageDescription
+
+let package = Package(name: "TLVCoding",
+                      products: [
+                        .library(
+                            name: "TLVCoding",
+                            targets: ["TLVCoding"]
+                        )
+                        ],
+                      targets: [
+                        .target(name: "TLVCoding", path: "./Sources"),
+                        .testTarget(name: "TLVCodingTests", dependencies: ["TLVCoding"])
+                        ],
+                      swiftLanguageVersions: [4])

Package@swift-4.2.swift

@@ -0,0 +1,15 @@
+// swift-tools-version:4.2
+import PackageDescription
+
+let package = Package(name: "TLVCoding",
+                      products: [
+                        .library(
+                            name: "TLVCoding",
+                            targets: ["TLVCoding"]
+                        )
+                        ],
+                      targets: [
+                        .target(name: "TLVCoding", path: "./Sources"),
+                        .testTarget(name: "TLVCodingTests", dependencies: ["TLVCoding"])
+                        ],
+                      swiftLanguageVersions: [.v4_2])

Sources/CodingKey.swift

@@ -0,0 +1,114 @@
+//
+//  CodingKey.swift
+//  TLVCoding
+//
+//  Created by Alsey Coleman Miller on 5/12/19.
+//  Copyright © 2019 PureSwift. All rights reserved.
+//
+
+public protocol TLVCodingKey: CodingKey {
+
+    init?(code: TLVTypeCode)
+
+    var code: TLVTypeCode { get }
+}
+
+public extension TLVCodingKey {
+
+    init?(intValue: Int) {
+
+        guard intValue <= Int(UInt8.max),
+            intValue >= Int(UInt8.min)
+            else { return nil }
+
+        self.init(code: TLVTypeCode(rawValue: UInt8(intValue)))
+    }
+
+    var intValue: Int? {
+        return Int(code.rawValue)
+    }
+}
+
+public extension TLVCodingKey where Self: RawRepresentable, Self.RawValue == TLVTypeCode.RawValue {
+
+    init?(code: TLVTypeCode) {
+        self.init(rawValue: code.rawValue)
+    }
+
+    var code: TLVTypeCode {
+        return TLVTypeCode(rawValue: rawValue)
+    }
+}
+
+#if swift(>=4.2)
+public extension TLVCodingKey where Self: CaseIterable, Self: RawRepresentable, Self.RawValue == TLVTypeCode.RawValue {
+
+    init?(stringValue: String) {
+
+        guard let value = Self.allCases.first(where: { $0.stringValue == stringValue })
+            else { return nil }
+
+        self = value
+    }
+}
+#endif
+
+internal extension TLVTypeCode {
+
+    init? <K: CodingKey> (codingKey: K) {
+
+        if let tlvCodingKey = codingKey as? TLVCodingKey {
+
+            self = tlvCodingKey.code
+
+        } else if let intValue = codingKey.intValue {
+
+            guard intValue <= Int(UInt8.max),
+                intValue >= Int(UInt8.min)
+                else { return nil }
+
+            self.init(rawValue: UInt8(intValue))
+
+        } else if MemoryLayout<K>.size == MemoryLayout<UInt8>.size,
+            Mirror(reflecting: codingKey).displayStyle == .enum {
+
+            self.init(rawValue: unsafeBitCast(codingKey, to: UInt8.self))
+
+        } else {
+
+            return nil
+        }
+    }
+}
+
+internal extension Sequence where Element == CodingKey {
+
+    /// KVC path string for current coding path.
+    var path: String {
+        return reduce("", { $0 + "\($0.isEmpty ? "" : ".")" + $1.stringValue })
+    }
+}
+
+internal extension CodingKey {
+
+    static var sanitizedName: String {
+
+        let rawName = String(reflecting: self)
+        #if swift(>=5.0)
+        var elements = rawName.split(separator: ".")
+        #else
+        var elements = rawName.components(separatedBy: ".")
+        #endif
+        guard elements.count > 2
+            else { return rawName }
+        elements.removeFirst()
+        #if swift(>=5.0)
+        elements.removeAll { $0.contains("(unknown context") }
+        #else
+        while let index = elements.index(where: { $0.contains("(unknown context") }) {
+            elements.remove(at: index)
+        }
+        #endif
+        return elements.reduce("", { $0 + ($0.isEmpty ? "" : ".") + $1 })
+    }
+}

Sources/Data.swift

@@ -0,0 +1,100 @@
+//
+//  Data.swift
+//  TLVCoding
+//
+//  Created by Alsey Coleman Miller on 5/12/19.
+//  Copyright © 2019 PureSwift. All rights reserved.
+//
+
+import Foundation
+
+internal extension Data {
+
+    #if swift(>=5.0) || (swift(>=4.2) && XCODE)
+    func subdataNoCopy(in range: Range<Int>) -> Data {
+
+        // stored in heap, can reuse buffer
+        if count > Data.inlineBufferSize {
+
+            #if swift(>=5.0)
+            return withUnsafeBytes { (buffer: UnsafeRawBufferPointer) in
+                Data(bytesNoCopy: UnsafeMutableRawPointer(mutating: buffer.baseAddress!.advanced(by: range.lowerBound)),
+                     count: range.count,
+                     deallocator: .none)
+            }
+            #else
+            return withUnsafeBytes {
+                Data(bytesNoCopy: UnsafeMutableRawPointer(mutating: $0.advanced(by: range.lowerBound)),
+                     count: range.count,
+                     deallocator: .none)
+            }
+            #endif
+
+        } else {
+
+            // stored in stack, must copy
+            return subdata(in: range)
+        }
+    }
+    #elseif swift(>=4.2)
+    func subdataNoCopy(in range: Range<Int>) -> Data {
+
+        return withUnsafeBytes {
+            Data(bytesNoCopy: UnsafeMutableRawPointer(mutating: $0.advanced(by: range.lowerBound)),
+                 count: range.count,
+                 deallocator: .none)
+        }
+    }
+    #elseif swift(>=4.0)
+    func subdataNoCopy(in range: CountableRange<Int>) -> Data {
+
+        let pointer = withUnsafeBytes { UnsafeMutableRawPointer(mutating: $0).advanced(by: range.lowerBound) }
+        return Data(bytesNoCopy: pointer, count: range.count, deallocator: .none)
+    }
+
+    /// Returns a new copy of the data in a specified range.
+    func subdata(in range: CountableRange<Int>) -> Data {
+        return Data(self[range])
+    }
+    #endif
+
+    func suffixNoCopy(from index: Int) -> Data {
+
+        return subdataNoCopy(in: index ..< count)
+    }
+
+    func suffixCheckingBounds(from start: Int) -> Data {
+
+        if count > start {
+
+            return Data(suffix(from: start))
+
+        } else {
+
+            return Data()
+        }
+    }
+}
+
+#if swift(>=5.0) || (swift(>=4.2) && XCODE)
+private extension Data {
+
+    /// Size of the inline buffer for `Foundation.Data` used in Swift 5.
+    ///
+    /// Used to determine wheather data is stored on stack or in heap.
+    static var inlineBufferSize: Int {
+
+        // Keep up to date
+        // https://github.com/apple/swift-corelibs-foundation/blob/master/Foundation/Data.swift#L621
+        #if arch(x86_64) || arch(arm64) || arch(s390x) || arch(powerpc64) || arch(powerpc64le)
+        typealias Buffer = (UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8, UInt8,
+            UInt8, UInt8, UInt8, UInt8, UInt8, UInt8) //len  //enum
+        #elseif arch(i386) || arch(arm)
+        typealias Buffer = (UInt8, UInt8, UInt8, UInt8,
+            UInt8, UInt8)
+        #endif
+
+        return MemoryLayout<Buffer>.size
+    }
+}
+#endif

Sources/DataConvertible.swift

@@ -0,0 +1,118 @@
+//
+//  DataConvertible.swift
+//  TLVCoding
+//
+//  Created by Alsey Coleman Miller on 5/12/19.
+//  Copyright © 2019 PureSwift. All rights reserved.
+//
+
+import Foundation
+
+/// Can be converted into data.
+internal protocol DataConvertible {
+
+    /// Append data representation into buffer.
+    static func += <T: DataContainer> (data: inout T, value: Self)
+
+    /// Length of value when encoded into data.
+    var dataLength: Int { get }
+}
+
+extension Data {
+
+    /// Initialize data with contents of value.
+    @inline(__always)
+    init <T: DataConvertible> (_ value: T) {
+        self.init(capacity: value.dataLength)
+        self += value
+    }
+
+    init <T: Sequence> (_ sequence: T) where T.Element: DataConvertible {
+
+        let dataLength = sequence.reduce(0, { $0 + $1.dataLength })
+        self.init(capacity: dataLength)
+        sequence.forEach { self += $0 }
+    }
+}
+
+// MARK: - UnsafeDataConvertible
+
+/// Internal Data casting protocol
+internal protocol UnsafeDataConvertible: DataConvertible { }
+
+extension UnsafeDataConvertible {
+
+    var dataLength: Int {
+        return MemoryLayout<Self>.size
+    }
+
+    /// Append data representation into buffer.
+    static func += <T: DataContainer> (data: inout T, value: Self) {
+        #if swift(>=4.2)
+        withUnsafePointer(to: value) {
+            $0.withMemoryRebound(to: UInt8.self, capacity: MemoryLayout<Self>.size) {
+                data.append($0, count: MemoryLayout<Self>.size)
+            }
+        }
+        #else
+        var value = value
+        withUnsafePointer(to: &value) {
+            $0.withMemoryRebound(to: UInt8.self, capacity: MemoryLayout<Self>.size) {
+                data.append($0, count: MemoryLayout<Self>.size)
+            }
+        }
+        #endif
+    }
+}
+
+extension UInt16: UnsafeDataConvertible { }
+extension UInt32: UnsafeDataConvertible { }
+extension UInt64: UnsafeDataConvertible { }
+
+// MARK: - DataContainer
+
+/// Data container type.
+internal protocol DataContainer: RandomAccessCollection where Self.Index == Int {
+
+    subscript(index: Int) -> UInt8 { get }
+
+    subscript(range: Range<Int>) -> Slice<Self> { get }
+
+    mutating func append(_ newElement: UInt8)
+
+    mutating func append(_ pointer: UnsafePointer<UInt8>, count: Int)
+
+    mutating func append <C: Collection> (contentsOf bytes: C) where C.Element == UInt8
+
+    #if swift(>=4.2)
+    static func += (lhs: inout Self, rhs: UInt8)
+    static func += <C: Collection> (lhs: inout Self, rhs: C) where C.Element == UInt8
+    #endif
+}
+
+extension DataContainer {
+
+    #if swift(>=4.2)
+    #else
+    static func += (lhs: inout Self, rhs: UInt8) {
+        lhs.append(rhs)
+    }
+
+    static func += <C: Collection> (lhs: inout Self, rhs: C) where C.Element == UInt8 {
+        lhs.append(contentsOf: rhs)
+    }
+    #endif
+
+    mutating func append <T: DataConvertible> (_ value: T) {
+        self += value
+    }
+}
+
+extension Data: DataContainer {
+
+    #if swift(>=4.2)
+    static func += (lhs: inout Data, rhs: UInt8) {
+        lhs.append(rhs)
+    }
+    #endif
+}