[$ swizzleMethod:@selector(foo) with:@selector(bar) in:[Foo class]]
    [$ swizzleMethod:@selector(foo) in:[Foo class] with:@selector(bar) in:[Bar class]]

    [$ swizzleClassMethod:@selector(foo) with:@selector(bar) in:[Foo class]]
    [$ swizzleClassMethod:@selector(foo) in:[Foo class] with:@selector(bar) in:[Bar class]]

    [$ homePath]     => path to user's home directory
    [$ desktopPath]  => path to user's desktop directory
    [$ documentPath] => path to user's document directory
    [$ appPath]      => path to app directory
    [$ resourcePath] => path to app's resources directory

    [$ waitUntil:^{ return (BOOL)(someConditionIsMet == YES) }]
    [$ waitUntil:^{ return (BOOL)(someConditionIsMet == YES) } timeOut:10.0]
    [$ waitUntil:^{ return (BOOL)(someConditionIsMet == YES) } timeOut:10.0 interval:0.1]

    @interface Foo
    - (id)initSingleton; // <= add these to the interface
    + (Foo *)sharedFoo;  // <= where Foo is the class name
    @end

    @implementation Foo
    $singleton(Foo);     // => makes Foo a singleton class

    - (id)initSingleton {
      foo = 1;           // do initialization in -initSingleton method
      bar = 2;
      return self;
    }
    @end

    $shared(Foo)         // => returns the shared instance
    /* or */
    [Foo sharedFoo]

    $new(Foo)       => [[[Foo alloc] init] autorelease]
    $eql(foo, bar)  => [foo isEqual:bar]
    $safe(obj)      => (obj == [NSNull null] ? nil : obj)

    $arr(foo, bar)          =>  [NSArray arrayWithObjects:foo, bar, nil]
    $marr(foo, bar)         =>  [NSMutableArray ...]
    $marrnew or $marr(nil)  =>  [NSMutableArray array]

    $set(foo, bar)          =>  [NSSet setWithObjects:foo, bar, nil]
    $mset(foo, bar)         =>  [NSMutableSet ...]
    $msetnew or $mset(nil)  =>  [NSMutableSet set]

    $dict(v1, k1, v2, k2)     =>  [NSDictionary dictionaryWithObjectsAndKeys:v1, k1, v2, k2, nil]
    $mdict(v1, k1, v2, k2)    =>  [NSMutableDictionary ...]
    $mdictnew or $mdict(nil)  =>  [NSMutableDictionary dictionary]

    $str(@"foo: %@", bar)   => [NSString stringWithFormat:@"foo: %@", bar]
    $mstr(@"foo: %@", bar)  => [NSMutableString ...]
    $mstrnew or $mstr(nil)  => [NSMutableString string]

    $bool(YES)    => [NSNumber numberWithBool:YES]
    $int(123)     => [NSNumber numberWithInt:123]
    $float(123.4) => [NSNumber numberWithFloat:123.4]

    $char(), $double(), $integer(), $long(), $longlong(), $short(),
    $uchar(), $uint(), $uinteger(), $ulong(), $ulonglong(), $ushort()

    $nonretained(), $pointer(), $point(), $range(), $rect(), $size()

    [array $first] => [array objectAtIndex:0]
    [array $last]  => [array lastObject]
    [array $at:1]  => [array objectAtIndex:1]

    [array $each:^(id obj) {
      NSLog(@"%@", obj);
    }]

    [array $eachWithIndex:^(id obj, NSUInteger i) {
      NSLog(@"%d %@", i, obj);
    }]

    [array $eachWithStop:^(id obj, BOOL *stop) {
      NSLog(@"%@", obj);
      if($eql(obj, @"foo")) {
        *stop = YES;
      }
    }]

    [array $eachWithIndexAndStop:^(id obj, NSUInteger i, BOOL *stop) {
      NSLog(@"%d %@", i, obj);
      if(i == 1) {
        *stop = YES;
      }
    }]

    [array $map:^(id obj) {
      return $integer([obj integerValue] * 2);
    }]

    [array $mapWithIndex:^(id obj, NSUInteger i) {
      return $integer([obj integerValue] * 2 + i);
    }]

    [array $reduce:^(id obj) {
      return $integer([obj integerValue] * 2);
    }]

    [array $reduce:^(NSNumber *memo, NSNumber *obj) {
      return $integer([memo integerValue] + [obj integerValue]);
    }]

    [array $reduceStartingAt:$integer(1) with:^(NSNumber *memo, NSNumber *obj) {
      return $integer([memo integerValue] * [obj integerValue]);
    }]

    [array $select:^BOOL(NSNumber *obj) {
      return ([obj integerValue] % 2) == 0;
    }]

    [array $detect:^BOOL(NSNumber *obj) {
      return ([obj integerValue] % 2) == 1;
    }]

    [array $join]      => [self componentsJoinedByString:@""]
    [array $join:@","] => [self componentsJoinedByString:@","]

    [array $push:foo]    => [array addObject:foo]              (+ returns self)
    [array $pop]         => [array removeLastObject]           (+ returns lastObject)
    [array $unshift:foo] => [array insertObject:foo atIndex:0] (+ returns self)
    [array $shift]       => [array removeObjectAtIndex:0]      (+ returns first object)

    [dict $for:@"foo"] => [dict objectForKey:@"foo"]
    [dict $keys]       => [dict allKeys]
    [dict $values]     => [dict allValues]

    [dict $each:^(id key, id value) {
        NSLog(@"%@ => %@", key, value);
    }

    [dict $eachWithStop:^(id key, id value, BOOL *stop) {
        NSLog(@"%@ => %@", key, value);
        if($eql(key, @"foo")) {
            *stop = YES;
        }
    }]

    [dict $eachKey:^(id key) {
        NSLog(@"%@", key);
    }]

    [dict $eachValue:^(id value) {
        NSLog(@"%@", value);
    }]

    [dict $obj:@"bar" for:@"foo"] => [dict setObject:@"bar" forKey:@"foo"] (+ returns self)

    [string $append:@"foo"]  => [string stringByAppendString:@"foo"]
    [string $prepend:@"foo"] => [NSString stringWithFormat:@"%@%@", @"foo", string]
    [string $split:@","]     => [string componentsSeparatedByString:@","]
    [string $split]          => [string componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]

    [string $append_:@"foo"]     => [string appendString:@"foo"]           (+ returns self)
    [string $prepend_:@"foo"]    => [string insertString:@"foo" atIndex:0] (+ returns self)
    [string $insert:@"foo" at:1] => [string insertString:@"foo" atIndex:1] (+ returns self)
    [string $set:@"foo"]         => [string setString:@"foo"]              (+ returns self)