14589365

gistfile1.m

#import <Foundation/Foundation.h>

typedef NS_ENUM(unsigned char, MyTreeVisitingOrder) {
    MyTreeOrderDepthFirst,
    MyTreeOrderValueFirst
};

#define Tree NSObject<MyTree>

@protocol MyTree
@property (nonatomic,strong) NSObject<NSCopying>* key;
@property (nonatomic,strong) NSObject *value;
@property (nonatomic,strong) NSMutableDictionary *children;
-(void) insertChild:(Tree*)node;
-(void) each:(void(^)(NSObject*))block order:(MyTreeVisitingOrder)order;
@end


@interface TreeImpl : NSObject <MyTree>
-(id) init __attribute__((unavailable("disabled")));
@end

@implementation TreeImpl

@synthesize key = _key;
@synthesize value = _value;
@synthesize children = _children;


-(id) initWithKey:(NSObject<NSCopying>*)key value:(NSObject*)value {
  self = [super init];
    if (self){
        _key = key;
        _value = value;
        _children = [NSMutableDictionary new];
    }
    return self;
}


-(void) insertChild:(Tree*)node {
    [_children setObject:node forKey:node.key];
}

-(void) each:(void(^)(NSObject*))block order:(MyTreeVisitingOrder)order {
    switch (order) {
        case MyTreeOrderDepthFirst:{
            if (_children) {
                for (id key in _children){
                    [[_children objectForKey:key] each:block order:order];
                }
            }
            block(_value);
            break;
        }
        case MyTreeOrderValueFirst:{
            block(_value);
            if (_children) {
                for (id key in _children){
                    [[_children objectForKey:key] each:block order:order];
                }
            }
            break;
        }
    }
}

@end


int main(int argc, char *argv[]) {
	@autoreleasepool {
        
        TreeImpl *a = [[TreeImpl alloc] initWithKey:@"A" value:@"A"];
        TreeImpl *b = [[TreeImpl alloc] initWithKey:@"B" value:@"B"];
        TreeImpl *c = [[TreeImpl alloc] initWithKey:@"C" value:@"C"];
        [a insertChild:b];
        [a insertChild:c];

		[a each:^(NSObject* value) {
		    NSLog(@"> %@",value);
		} order:MyTreeOrderValueFirst];
		return EXIT_SUCCESS;
	}
}