aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

update meta data

Browse source
This commit is contained in:
Ingy döt Net 2013-04-11 12:07:39 -07:00
parent f3a896c724
commit 90e15ed6ce
3307 changed files with 1674 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

14
Task/Classes/00DESCRIPTION Normal file
View file

@ -0,0 +1,14 @@
In [[object-oriented programming]] '''class''' is a set (a [[wp:Transitive_closure|transitive closure]]) of types bound by the relation of [[inheritance]]. It is said that all types derived from some base type T and the type T itself form a class T. The first type T from the class T sometimes is called the '''root type''' of the class.
A class of types itself, as a type, has the values and operations of its own. The operations of are usually called '''methods''' of the root type. Both operations and values are called [[polymorphism | polymorphic]].
A polymorphic operation (method) selects an implementation depending on the actual specific type of the polymorphic argument. The action of choice the type-specific implementation of a polymorphic operation is called '''dispatch'''. Correspondingly, polymorphic operations are often called '''dispatching''' or '''virtual'''. Operations with multiple arguments and/or the results of the class are called '''multi-methods'''. A further generalization of is the operation with arguments and/or results from different classes.
* single-dispatch languages are those that allow only one argument or result to control the dispatch. Usually it is the first parameter, often hidden, so that a prefix notation ''x''.''f''() is used instead of mathematical ''f''(''x'').
* multiple-dispatch languages allow many arguments and/or results to control the dispatch.
A polymorphic value has a type tag indicating its specific type from the class and the corresponding specific value of that type. This type is sometimes called '''the most specific type''' of a [polymorphic] value. The type tag of the value is used in order to resolve the dispatch. The set of polymorphic values of a class is a transitive closure of the sets of values of all types from that class.
In many [[object-oriented programming | OO]] languages the type of the class of T and T itself are considered equivalent. In some languages they are distinct (like in [[Ada]]). When class T and T are equivalent, there is no way to distinguish polymorphic and specific values.
The purpose of this task is to create a basic class with a method, a constructor, an instance variable and how to instantiate it.