www.delorie.com/gnu/docs/libobjects/libobjects_6.html

search

	Buy GNU books!

User's Guide to the GNU Objective-C Class Library

4. Organization

The library is built around several protocols:

• The <Collecting> protocol is root of the collection protocol heirarchy. The <Collecting> protocol defines the most general interface to a collection of elements. Elements can be added, removed, and replaced. The contents can be tested, enumerated, and enumerated through various filters. Elements may be objects, or any C type included in the "elt" union given in elt.h, but all elements of a collection must be of the same C type. (For examples see Set and Bag.)

• The <KeyedCollecting> protocol inherits from the <Collecting> protocol. The <KeyedCollecting> protocol defines the interface to a collection of elements that are accessible by a key, where the key is some unique element. Pairs of (key element, content element) may be added, removed and replaced. The keys and contents may be tested, enumerated, and copied. (For examples see Dictionary and MappedCollector.)

• The <IndexedCollecting> protocol inherits from the <KeyedCollecting> protocol. The <IndexedCollecting> protocol defines the interface to a collection of elements that are accessible by a key that is an index, where the indeces in a collection are a contiguous series of unsigned integers beginning at 0. This is the root of the protocol heirarchy for all collections that hold their elements in some order. Elements may be accessed, inserted, replaced and removed by their index. (For examples see Array and LinkedList.)

• The <LinkedListComprising> protocol defines the interface to an object that may be an element in a LinkedList. LinkedList is a collection object based on a doubly linked list. (For an example see LinkedListNode.)

• The <BinaryTreeComprising> protocol defines the interface to an object that may be an element in a BinaryTree. BinaryTree is a collection object based on a binary trees. (For an example see BinaryTreeNode.)

Here is the object inheritance heirarchy. All collection abtract superclasses (classes which are not usable without subclassing) end with "Collection"; all protocols end with "ing"; all collection protocols end with "Collecting".

Collection <Collecting> Set Bag KeyedCollection <KeyedCollecting> Dictionary MappedCollector IndexedCollection <IndexedCollecting> Array Stack GapArray CircularArray Queue Heap LinkedList BinaryTree RBTree EltNodeCollector String DelegatePool LinkedListNode LinkedListEltNode BinaryTreeNode BinaryTreeEltNode RBTreeNode RBTreeEltNode Stream StdioStream MemoryStream Coder TextCoder BinaryCoder ConnectedCoder Port <Coding> SocketPort Connection Proxy <Coding> Magnitude Time Random RNGBerkeley <RandomGenerating> RNGAdditiveCongruential <RandomGenerating>

<<This section unfinished.>>