#import <Foundation/Foundation.h>

@interface NSArray (FunctionalUtil)

/// Returns true when any of the items in this array match the given predicate.
-(bool) any:(int (^)(id item))predicate;

/// Returns true when all of the items in this array match the given predicate.
-(bool) all:(int (^)(id item))predicate;

/// Returns the first item in this array that matches the given predicate, or else returns nil if none match it.
-(id) firstMatchingElseNil:(int (^)(id item))predicate;

/// Returns an array of all the results of passing items from this array through the given projection function.
-(NSArray*) map:(id (^)(id item))projection;

/// Returns an array of all the results of passing items from this array through the given projection function.
-(NSArray*) filter:(int (^)(id item))predicate;

/// Returns the sum of the doubles in this array of doubles.
-(double) sumDouble;

/// Returns the sum of the unsigned integers in this array of unsigned integers.
-(NSUInteger) sumNSUInteger;

/// Returns the sum of the integers in this array of integers.
-(NSInteger) sumNSInteger;

-(NSDictionary *)keyedBy:(id(^)(id))keySelector;
-(NSDictionary *)groupBy:(id(^)(id value))keySelector;

@end