//NSCharacterSet其实是许多字符或者数字或者符号的组合，在网络处理的时候会用到

//Creating a Standard Character Set
+ (NSCharacterSet *)controlCharacterSet;  //控制符
+ (NSCharacterSet *)whitespaceCharacterSet;//空格
+ (NSCharacterSet *)whitespaceAndNewlineCharacterSet;//空白&换行符
+ (NSCharacterSet *)decimalDigitCharacterSet;  //小数
+ (NSCharacterSet *)letterCharacterSet;   //文字
+ (NSCharacterSet *)lowercaseLetterCharacterSet;//小写字母
+ (NSCharacterSet *)uppercaseLetterCharacterSet;//大写字母
+ (NSCharacterSet *)nonBaseCharacterSet;       //非基础字母
+ (NSCharacterSet *)alphanumericCharacterSet;  //字母数字
+ (NSCharacterSet *)decomposableCharacterSet;  //可分解
+ (NSCharacterSet *)illegalCharacterSet;       //非法
+ (NSCharacterSet *)punctuationCharacterSet;   //标点
+ (NSCharacterSet *)capitalizedLetterCharacterSet;  //首字母大写
+ (NSCharacterSet *)symbolCharacterSet;             //符号
+ (NSCharacterSet *)newlineCharacterSet NS_AVAILABLE(10_5, 2_0);//换行符


// Creating and Managing Character Sets as Bitmap Representations

//Returns a character set containing characters with Unicode values in a given range.
+ (NSCharacterSet *)characterSetWithRange:(NSRange)aRange;

// Returns a character set containing the characters in a given string.
+ (NSCharacterSet *)characterSetWithCharactersInString:(NSString *)aString;

//Returns a character set containing characters determined by a given bitmap representation.
+ (NSCharacterSet *)characterSetWithBitmapRepresentation:(NSData *)data;
+ (nullable NSCharacterSet *)characterSetWithContentsOfFile:(NSString *)fName;

//A character set containing only characters that don’t exist in the receiver. (read-only)
invertedSet

//  Testing Set Membership


- (BOOL)characterIsMember:(unichar)aCharacter;

//Returns a Boolean value that indicates whether a given long character is a member of the receiver.
- (BOOL)longCharacterIsMember:(UTF32Char)theLongChar;
- (BOOL)isSupersetOfSet:(NSCharacterSet *)theOtherSet;
- (BOOL)hasMemberInPlane:(uint8_t)thePlane;
@end

@interface NSMutableCharacterSet : NSCharacterSet <NSCopying, NSMutableCopying>

- (void)addCharactersInRange:(NSRange)aRange;
- (void)removeCharactersInRange:(NSRange)aRange;
- (void)addCharactersInString:(NSString *)aString;
- (void)removeCharactersInString:(NSString *)aString;
- (void)formUnionWithCharacterSet:(NSCharacterSet *)otherSet;
- (void)formIntersectionWithCharacterSet:(NSCharacterSet *)otherSet;
- (void)invert;

+ (NSMutableCharacterSet *)controlCharacterSet;
+ (NSMutableCharacterSet *)whitespaceCharacterSet;
+ (NSMutableCharacterSet *)whitespaceAndNewlineCharacterSet;
+ (NSMutableCharacterSet *)decimalDigitCharacterSet;
+ (NSMutableCharacterSet *)letterCharacterSet;
+ (NSMutableCharacterSet *)lowercaseLetterCharacterSet;
+ (NSMutableCharacterSet *)uppercaseLetterCharacterSet;
+ (NSMutableCharacterSet *)nonBaseCharacterSet;
+ (NSMutableCharacterSet *)alphanumericCharacterSet;
+ (NSMutableCharacterSet *)decomposableCharacterSet;
+ (NSMutableCharacterSet *)illegalCharacterSet;
+ (NSMutableCharacterSet *)punctuationCharacterSet;
+ (NSMutableCharacterSet *)capitalizedLetterCharacterSet;
+ (NSMutableCharacterSet *)symbolCharacterSet;
+ (NSMutableCharacterSet *)newlineCharacterSet NS_AVAILABLE(10_5, 2_0);

+ (NSMutableCharacterSet *)characterSetWithRange:(NSRange)aRange;
+ (NSMutableCharacterSet *)characterSetWithCharactersInString:(NSString *)aString;
+ (NSMutableCharacterSet *)characterSetWithBitmapRepresentation:(NSData *)data;
+ (nullable NSMutableCharacterSet *)characterSetWithContentsOfFile:(NSString *)fName;