Awesome

TJFunctionalAdditions

Note: I've done this as an exercise for myself. For production, I suggest using Underscore.m, which I use myself in my projects right now.

Library simplifying the use of collection iterations through functional constructs like map, select, reject, etc.

They are simply used as categories, without the need for some cumbersome wrappers.

Methods

Added to NSArray:

• each
• map
• filter
• reject
• reduce
• take
• last
• any
• all

Added to NSDictionary:

• each

Sample usage

NSArray

// Filter
NSArray *filterResult = [testArray filter:^BOOL(NSNumber *element) {
    return [element intValue] % 2 == 0;
}];

// Map
NSArray *mapResult = [testArray map:^id(NSString *string) {
    return [string uppercaseString];
}];

// Any
BOOL anyElementGreaterThan = [testArray any:^BOOL(id element) {
    return [element intValue] > 10;
}];

// Reduce
NSNumber *number1 = [NSNumber numberWithInt:1];
NSNumber *number2 = [NSNumber numberWithInt:2];
NSNumber *number3 = [NSNumber numberWithInt:3];
NSNumber *number4 = [NSNumber numberWithInt:4];

NSArray *testArray = [NSArray arrayWithObjects:number1, number2, number3, number4, nil];

NSNumber *factorial = [testArray reduceWithInitialValue:[NSNumber numberWithInt:1] withBlock:^id(NSNumber *currentValue, NSNumber *element) {
    int factorial = [currentValue intValue] * [element intValue];
    return [NSNumber numberWithInt:factorial];
}];

NSDictionary

// Each
[dictionary each:^(NSString *key, NSNumber *value) {
    NSLog(@"There's value %i for key %@!", [value intValue], key);
}];

See more samples in Tests.