Separate parser and helpers from Password class for better testability

passKit/Parser/AdditionField.swift

@@ -0,0 +1,47 @@
+//
+//  AdditionField.swift
+//  passKit
+//
+//  Created by Danny Moesch on 30.09.18.
+//  Copyright © 2018 Bob Sun. All rights reserved.
+//
+
+public struct AdditionField: Hashable {
+
+    public let title: String, content: String
+
+    var asString: String {
+        return title.isEmpty ? content : title + ": " + content
+    }
+
+    var asTuple: (String, String) {
+        return (title, content)
+    }
+}
+
+extension AdditionField {
+
+    static func | (left: String, right: AdditionField) -> String {
+        return left | right.asString
+    }
+
+    static func | (left: AdditionField, right: String) -> String {
+        return left.asString | right
+    }
+
+    static func | (left: AdditionField, right: AdditionField) -> String {
+        return left.asString | right
+    }
+}
+
+extension AdditionField: Equatable {
+    
+    public static func == (first: AdditionField, second: AdditionField) -> Bool {
+        return first.asTuple == second.asTuple
+    }
+}
+
+infix operator =>: MultiplicationPrecedence
+func => (key: String, value: String) -> AdditionField {
+    return AdditionField(title: key, content: value)
+}