函数式编程------->链式编程
函数式编程：
#import "Person.h"
@implementation Person
- (void)eat:(NSString*)doSomething{
NSLog(@"Today %@ %@",NSStringFromSelector(_cmd),doSomething);
}
- (void)run:(NSString*)doSomething{
NSLog(@"Today %@ %@",NSStringFromSelector(_cmd),doSomething);
}
调用方式
Person* person = [Person new];
[person eat:@"fish"];
[person run:@"10km"];
我们最终目的是将函数式编程转换为链式编程：
首先将调用方式转换为
[[person eat:@"fish"] run:@"10km"];
要想调用完eat函数后继续调用run函数，则eat函数需返回当前对象。
修改后函数：
- (Person* )eat:(NSString*)doSomething{
NSLog(@"Today %@ %@",NSStringFromSelector(_cmd),doSomething);
return self;
}
- (Person* )run:(NSString*)doSomething{
NSLog(@"Today %@ %@",NSStringFromSelector(_cmd),doSomething);
return self;
}
此时仍为函数式调用
下一步将函数式转换为链式，如何采用()的方式传参，需要使用OC中block，点语法返回需要调用的block，调用时即可采用()方式传参。同时设置block的返回值为当前对象，即可实现链式编程。
#import <Foundation/Foundation.h>
@class Person;
typedef Person* (^RunBlock) (NSString* doSomething);
@interface Person : NSObject
- (RunBlock)eat;
- (RunBlock)run;
@end
#import "Person.h"
@implementation Person
- (RunBlock)eat{
RunBlock block = ^(NSString* doSomething){
NSLog(@"Today %@ %@",NSStringFromSelector(_cmd),doSomething);
return self;
};
return block;
}
- (RunBlock)run{
RunBlock block = ^(NSString* doSomething){
NSLog(@"Today %@ %@",NSStringFromSelector(_cmd),doSomething);
return self;
};
return block;
}
@end
调用方法
person.eat(@"fish").run(@"10km");
