Merge pull request #107 from vapor/hex

add hexEncoded + lossless data

Sources/Core/CoreError.swift

@@ -0,0 +1,8 @@
+public struct CoreError: Debuggable, Error {
+    public var identifier: String
+    public var reason: String
+    public init(identifier: String, reason: String) {
+        self.identifier = identifier
+        self.reason = reason
+    }
+}

Sources/Core/Data+Hex.swift

@@ -0,0 +1,16 @@
+extension Data {
+    public func hexEncodedString() -> String {
+        var bytes = Data()
+        bytes.reserveCapacity(self.count * 2)
+
+        for byte in self {
+            bytes.append(radix16table[Int(byte / 16)])
+            bytes.append(radix16table[Int(byte % 16)])
+        }
+
+        return String(bytes: bytes, encoding: .utf8)!
+    }
+}
+
+
+fileprivate let radix16table: [UInt8] = [0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66]

Sources/Core/LosslessDataConvertible.swift

@@ -0,0 +1,49 @@
+/// A type that can be represented as Data in a lossless, unambiguous way.
+public protocol LosslessDataConvertible {
+    /// Losslessly converts this type to `Data`.
+    func convertToData() throws -> Data
+
+    /// Losslessly converts `Data` to this type.
+    static func convertFromData(_ data: Data) throws -> Self
+}
+
+extension String: LosslessDataConvertible {
+    /// Converts this `String` to data using `.utf8`.
+    public func convertToData() -> Data {
+        return Data(utf8)
+    }
+
+    /// Converts `Data` to a `utf8` encoded String.
+    ///
+    /// - throws: Error if String is not UTF8 encoded.
+    public static func convertFromData(_ data: Data) throws -> String {
+        guard let string = String(data: data, encoding: .utf8) else {
+            throw CoreError(identifier: "stringData", reason: "String not UTF-8 encoded")
+        }
+        return string
+    }
+}
+
+extension Array: LosslessDataConvertible where Element == UInt8 {
+    /// Converts this `[UInt8]` to `Data`.
+    public func convertToData() -> Data {
+        return Data(bytes: self)
+    }
+
+    /// Converts `Data` to `[UInt8]`.
+    public static func convertFromData(_ data: Data) -> Array<UInt8> {
+        return .init(data)
+    }
+}
+
+extension Data: LosslessDataConvertible {
+    /// `LosslessDataConvertible` conformance.
+    public func convertToData() throws -> Data {
+        return self
+    }
+
+    /// `LosslessDataConvertible` conformance.
+    public static func convertFromData(_ data: Data) -> Data {
+        return data
+    }
+}