stanislaw/iOS-Projects-Catalogue — pull request #81 by stanislaw (2014-10-29 17:10:32+00:00)
Title: Extensions for Objective-C: add Underscore.m

# Underscore.m

## About Underscore.m

Underscore.m is a small utility library to facilitate working with common data structures in Objective-C.
It tries to encourage chaining by eschewing the square bracket]]]]]].
It is inspired by the awesome [underscore.js][js].

[js]: http://documentcloud.github.com/underscore

## Real world example

```objective-c
// First, let's compose a twitter search request
NSURL *twitterSearch = [NSURL URLWithString:@"http://search.twitter.com/search.json?q=@SoundCloud&rpp=100"];

// ... then we fetch us some json ...
NSData *data = [NSData dataWithContentsOfURL:twitterSearch];

// ... and parse it.
NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data
options:kNilOptions
error:NULL];

// This is where the fun starts!
NSArray *tweets = [json valueForKey:@"results"];

NSArray *processed = _array(tweets)
// Let's make sure that we only operate on NSDictionaries, you never
// know with these APIs ;-)
.filter(Underscore.isDictionary)
// Remove all tweets that are in English
.reject(^BOOL (NSDictionary *tweet) {
return [[tweet valueForKey:@"iso_language_code"] isEqualToString:@"en"];
})
// Create a simple string representation for every tweet
.map(^NSString *(NSDictionary *tweet) {
NSString *name = [tweet valueForKey:@"from_user_name"];
NSString *text = [tweet valueForKey:@"text"];

return [NSString stringWithFormat:@"%@: %@", name, text];
})
.unwrap;
```

## Documentation

Documentation for Underscore.m can be found on [the website](http://underscorem.org).