Cocoa Touch: что выпустить, когда выпустить?

Я изо всех сил пытаюсь понять, когда и что я должен выпустить в Cocoa Touch, поскольку в нем нет сборки мусора.

Этот блок кода взят из примера PeriodicElements от apple iphone, и они выпускают anElement и rawElementArray, но не thePath, firstLetter, existsArray и tempArray?

Я бы подумал, что хотя бы tempArray и существующий массив должны быть освобождены.

Может кто-нибудь умный объяснит мне, почему?

Спасибо :)

- (void)setupElementsArray {
NSDictionary *eachElement;

// create dictionaries that contain the arrays of element data indexed by
// name
self.elementsDictionary = [NSMutableDictionary dictionary];
// physical state
self.statesDictionary = [NSMutableDictionary dictionary];
// unique first characters (for the Name index table)
self.nameIndexesDictionary = [NSMutableDictionary dictionary];

// create empty array entries in the states Dictionary or each physical state
[statesDictionary setObject:[NSMutableArray array] forKey:@"Solid"];
[statesDictionary setObject:[NSMutableArray array] forKey:@"Liquid"];
[statesDictionary setObject:[NSMutableArray array] forKey:@"Gas"];
[statesDictionary setObject:[NSMutableArray array] forKey:@"Artificial"];

// read the element data from the plist
NSString *thePath = [[NSBundle mainBundle]  pathForResource:@"Elements" ofType:@"plist"];
NSArray *rawElementsArray = [[NSArray alloc] initWithContentsOfFile:thePath];

// iterate over the values in the raw elements dictionary
for (eachElement in rawElementsArray)
{
    // create an atomic element instance for each
    AtomicElement *anElement = [[AtomicElement alloc] initWithDictionary:eachElement];

    // store that item in the elements dictionary with the name as the key
    [elementsDictionary setObject:anElement forKey:anElement.name];

    // add that element to the appropriate array in the physical state dictionary 
    [[statesDictionary objectForKey:anElement.state] addObject:anElement];

    // get the element's initial letter
    NSString *firstLetter = [anElement.name substringToIndex:1];
    NSMutableArray *existingArray;

    // if an array already exists in the name index dictionary
    // simply add the element to it, otherwise create an array
    // and add it to the name index dictionary with the letter as the key
    if (existingArray = [nameIndexesDictionary valueForKey:firstLetter]) 
    {
    [existingArray addObject:anElement];
    } else {
        NSMutableArray *tempArray = [NSMutableArray array];
        [nameIndexesDictionary setObject:tempArray forKey:firstLetter];
        [tempArray addObject:anElement];
    }

    // release the element, it is held by the various collections
    [anElement release];

}
// release the raw element data
[rawElementsArray release];



// create the dictionary containing the possible element states
// and presort the states data
self.elementPhysicalStatesArray = [NSArray arrayWithObjects:@"Solid",@"Liquid",@"Gas",@"Artificial",nil];
[self presortElementsByPhysicalState];

// presort the dictionaries now
// this could be done the first time they are requested instead

[self presortElementInitialLetterIndexes];

self.elementsSortedByNumber = [self presortElementsByNumber];
self.elementsSortedBySymbol = [self presortElementsBySymbol];

}