添加一个与字符串做比较的协议

MRFramework/MRFramework/Extensions/Foundation/String+util.swift

@@ -128,6 +128,7 @@ extension String {
     }
 }
 
+// MARK: - Calculate text size
 extension String {
     public func size(with attributes: MRStringAttribute ..., fixedWidth: CGFloat) -> CGSize {
         guard count > 0 && fixedWidth > 0 else {
@@ -157,3 +158,39 @@ extension String {
         return DataURLParser<UIImage>.parserDataURL(self)
     }
 }
+
+// MARK: - Compare with MRCompareToString
+extension String {
+    public static func == <T: MRCompareToString>(lhs: Self, rhs: T) -> Bool {
+        return rhs.compare(with: lhs) == .orderedSame
+    }
+    
+    public static func < <T: MRCompareToString>(lhs: Self, rhs: T) -> Bool {
+        return rhs.compare(with: lhs) == .orderedDescending
+    }
+    
+    public static func <= <T: MRCompareToString>(lhs: Self, rhs: T) -> Bool {
+        let rs = rhs.compare(with: lhs)
+        return rs == .orderedSame || rs == .orderedDescending
+    }
+    
+    public static func > <T: MRCompareToString>(lhs: Self, rhs: T) -> Bool {
+        return rhs.compare(with: lhs) == .orderedAscending
+    }
+    
+    public static func >= <T: MRCompareToString>(lhs: Self, rhs: T) -> Bool {
+        let rs = rhs.compare(with: lhs)
+        return rs == .orderedSame || rs == .orderedAscending
+    }
+}
+
+/// 比较字符串的协议。任意类遵守该协议来实现跟字符串比较
+public protocol MRCompareToString: Comparable {
+    static func < (lhs: Self, rhs: String) -> Bool
+    static func <= (lhs: Self, rhs: String) -> Bool
+    static func > (lhs: Self, rhs: String) -> Bool
+    static func >= (lhs: Self, rhs: String) -> Bool
+    static func == (lhs: Self, rhs: String) -> Bool
+    
+    func compare(with string: String) -> ComparisonResult
+}