30分钟快速带你理解iOS中的谓词NSPredicate

//通过格式化字符串来进行谓词对象的初始化
+ (NSPredicate *)predicateWithFormat:(NSString *)predicateFormat argumentArray:(nullable NSArray *)arguments;
+ (NSPredicate *)predicateWithFormat:(NSString *)predicateFormat, ...;
+ (NSPredicate *)predicateWithFormat:(NSString *)predicateFormat arguments:(va_list)argList;

 //检索属性length为5的对象
 NSPredicate * predicate = [NSPredicate predicateWithFormat:@"length = 5"];
 //对于这个数组中的字符串，即是检索字符串长度为5的元素
 NSArray * test = @[@"sda",@"321",@"sf12",@"dsdwq1",@"swfas"];
 NSArray * result = [test filteredArrayUsingPredicate:predicate];
 //将打印@[@"swfas"]
 NSLog(@"%@",result);

NSPredicate * predicate = [NSPredicate predicateWithFormat:@"name = %@ && age = \"25\"",name];

 NSString * key = @"length";
 NSPredicate * predicate = [NSPredicate predicateWithFormat:@"%K = 5",key];
 NSArray * test = @[@"sda",@"321",@"sf12",@"dsdwq1",@"swfas"];
 NSArray * result = [test filteredArrayUsingPredicate:predicate];
 //将打印@[@"swfas"]
 NSLog(@"%@",result);

 NSPredicate * predicate = [NSPredicate predicateWithFormat:@"length = $LENGTH"];
 predicate = [predicate predicateWithSubstitutionVariables:@{@"LENGTH":@5}];
 NSArray * test = @[@"sda",@"321",@"sf12",@"dsdwq1",@"swfas"];
 NSArray * result = [test filteredArrayUsingPredicate:predicate];
 //将打印@[@"swfas"]
 NSLog(@"%@",result);

//创建一个总是验证通过(YES)或不通过(NO)的谓词对象
/*
如果创建的是验证通过的，则任何检索都会成功进行返回，否则任何检索都会失败不返回任何对象
*/
+ (NSPredicate *)predicateWithValue:(BOOL)value;
//自定义实现检索函数
/*

NSPredicate * predicate = [NSPredicate predicateWithBlock:^BOOL(id _Nullable evaluatedObject, NSDictionary<NSString *,id> * _Nullable bindings) {
 if ([evaluatedObject length]==5) {
 return YES;
 }
 return NO;
 }];
*/
+ (NSPredicate*)predicateWithBlock:(BOOL (^)(id _Nullable evaluatedObject, NSDictionary<NSString *, id> * _Nullable bindings))block;
//格式化字符串属性
@property (readonly, copy) NSString *predicateFormat; 
//当使用谓词模板来进行对象创建时，这个函数用来设置谓词模板中变量替换
- (instancetype)predicateWithSubstitutionVariables:(NSDictionary<NSString *, id> *)variables;
//检查一个Object对象是否可以通过验证
- (BOOL)evaluateWithObject:(nullable id)object; 
//用谓词模板进行对象的验证
- (BOOL)evaluateWithObject:(nullable id)object substitutionVariables:(nullable NSDictionary<NSString *, id> *)bindings;

 //创建左侧表达式对象 对应为键
 NSExpression * left = [NSExpression expressionForKeyPath:@"length"];
 //创建右侧表达式对象 对应为值
 NSExpression * right = [NSExpression expressionForConstantValue:[NSNumber numberWithInt:5]];
 //创建比较谓词对象 这里设置为严格等于
 NSComparisonPredicate * pre = [NSComparisonPredicate predicateWithLeftExpression:left rightExpression:right modifier:NSDirectPredicateModifier type:NSEqualToPredicateOperatorType options:NSCaseInsensitivePredicateOption];
 NSArray * test = @[@"sda",@"321",@"sf12",@"dsdwq1",@"swfas"];
 NSArray * result = [test filteredArrayUsingPredicate:pre];
 //将打印@[@"swfas"]
 NSLog(@"%@",result);

typedef NS_ENUM(NSUInteger, NSComparisonPredicateModifier) {
 NSDirectPredicateModifier = 0, //直接进行比较操作
 NSAllPredicateModifier, //用于数组或集合 只有当内部所有元素都通过验证时 集合才算通过
 NSAnyPredicateModifier //同于数组或集合 当内部有一个元素满足时 集合算通过验证
};

 NSPredicate * pre = [NSPredicate predicateWithFormat:@"ALL length = 5"];
 NSArray * test = @[@[@"aaa",@"aa"],@[@"bbbb",@"bbbbb"],@[@"ccccc",@"ccccc"]];
 NSArray * result = [test filteredArrayUsingPredicate:pre];
 //将打印@[@[@"ccccc",@"ccccc"]]
 NSLog(@"%@",result);

typedef NS_ENUM(NSUInteger, NSPredicateOperatorType) {
 NSLessThanPredicateOperatorType = 0, // 小于
 NSLessThanOrEqualToPredicateOperatorType, // 小于等于
 NSGreaterThanPredicateOperatorType, // 大于
 NSGreaterThanOrEqualToPredicateOperatorType, // 大于等于
 NSEqualToPredicateOperatorType, // 等于
 NSNotEqualToPredicateOperatorType, //不等于
 NSMatchesPredicateOperatorType, //正则比配
 NSLikePredicateOperatorType, //Like匹配 与SQL类似
 NSBeginsWithPredicateOperatorType, //左边的表达式 以右边的表达式作为开头
 NSEndsWithPredicateOperatorType,//左边的表达式 以右边的表达式作为结尾
 NSInPredicateOperatorType, // 左边的表达式 出现在右边的集合中 
 NSCustomSelectorPredicateOperatorType,//使用自定义的函数来进行 验证
 NSContainsPredicateOperatorType, //左边的集合包括右边的元素
 NSBetweenPredicateOperatorType //左边表达式的值在右边的范围中 例如 1 BETWEEN { 0 , 33 }
};

//如果不需要特殊指定 这个枚举值也可以传0
typedef NS_OPTIONS(NSUInteger, NSComparisonPredicateOptions) {
 NSCaseInsensitivePredicateOption = 0x01, //不区分大小写
 NSDiacriticInsensitivePredicateOption = 0x02,//不区分读音符号
 NSNormalizedPredicateOption //比较前进行预处理 代替上面两个选项
};

//通过格式化字符串创建表达式
+ (NSExpression *)expressionWithFormat:(NSString *)expressionFormat argumentArray:(NSArray *)arguments;
+ (NSExpression *)expressionWithFormat:(NSString *)expressionFormat, ...;
+ (NSExpression *)expressionWithFormat:(NSString *)expressionFormat arguments:(va_list)argList;
//直接通过对象创建常亮的表达式
+ (NSExpression *)expressionForConstantValue:(nullable id)obj; 
//创建变量表达式 验证时将从binding字典中进行替换
+ (NSExpression *)expressionForVariable:(NSString *)string; 
//将多个表达式组合成一个
+ (NSExpression *)expressionForAggregate:(NSArray<NSExpression *> *)subexpressions;
+ (NSExpression *)expressionForUnionSet:(NSExpression *)left with:(NSExpression *)right;
+ (NSExpression *)expressionForIntersectSet:(NSExpression *)left with:(NSExpression *)right;
+ (NSExpression *)expressionForMinusSet:(NSExpression *)left with:(NSExpression *)right;
+ (NSExpression *)expressionForSubquery:(NSExpression *)expression usingIteratorVariable:(NSString *)variable predicate:(NSPredicate *)predicate;
//通过预定义的函数和参数数组来构建表达式对象 预定义的函数 可见dev开发文档
+ (NSExpression *)expressionForFunction:(NSString *)name arguments:(NSArray *)parameters;

//进行对象初始化
/*
typedef NS_ENUM(NSUInteger, NSCompoundPredicateType) {
 NSNotPredicateType = 0, //取非
 NSAndPredicateType, //与运算 
 NSOrPredicateType, //或运算
};
*/
- (instancetype)initWithType:(NSCompoundPredicateType)type subpredicates:(NSArray<NSPredicate *> *)subpredicates;
//快速创建与运算
+ (NSCompoundPredicate *)andPredicateWithSubpredicates:(NSArray<NSPredicate *> *)subpredicates;
//快速创建或运算
+ (NSCompoundPredicate *)orPredicateWithSubpredicates:(NSArray<NSPredicate *> *)subpredicates;
//快速创建非运算
+ (NSCompoundPredicate *)notPredicateWithSubpredicate:(NSPredicate *)predicate;

@interface NSArray<ObjectType> (NSPredicateSupport)
//不可变数组使用过滤器后返回新数组
- (NSArray<ObjectType> *)filteredArrayUsingPredicate:(NSPredicate *)predicate; 
@end
@interface NSMutableArray<ObjectType> (NSPredicateSupport)
//可变数组可以直接进行过滤操作
- (void)filterUsingPredicate:(NSPredicate *)predicate;
@end
@interface NSSet<ObjectType> (NSPredicateSupport)
//不可变集合过滤后返回新集合
- (NSSet<ObjectType> *)filteredSetUsingPredicate:(NSPredicate *)predicate;
@end
@interface NSMutableSet<ObjectType> (NSPredicateSupport)
//可变集合可以直接进行过滤操作
- (void)filterUsingPredicate:(NSPredicate *)predicate;
@end
@interface NSOrderedSet<ObjectType> (NSPredicateSupport)
- (NSOrderedSet<ObjectType> *)filteredOrderedSetUsingPredicate:(NSPredicate *)p;
@end
@interface NSMutableOrderedSet<ObjectType> (NSPredicateSupport)
- (void)filterUsingPredicate:(NSPredicate *)p;
@end