Karl Jones at 14:29, 20 September 2016

2016-09-20T14:29:40Z

Karl Jones: Created page with "In programming languages and type theory, '''polymorphism''' (from Greek πολύς, ''polys'', "many, much" and μορφή, ''morphē'', "form, s..."

2016-09-20T14:20:42Z

Created page with "In programming languages and type theory, '''polymorphism''' (from Greek πολύς, ''polys'', "many, much" and μορφή, ''morphē'', "form, s..."

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In [[Programming language|programming languages]] and [[type theory]], '''polymorphism''' (from Greek πολύς, ''polys'', "many, much" and μορφή, ''morphē'', "form, shape") is the provision of a single [[Interface (computing)|interface]] to entities of different [[Data type|data types]].

== Description ==

A polymorphic type is one whose operations can also be applied to values of some other type, or types.

There are several fundamentally different kinds of polymorphism:

* Ad hoc polymorphism: when a function denotes different and potentially heterogeneous implementations depending on a limited range of individually specified types and combinations. Ad hoc polymorphism is supported in many languages using function overloading.
* Parametric polymorphism: when code is written without mention of any specific type and thus can be used transparently with any number of new types. In the object-oriented programming community, this is often known as generics or generic programming. In the functional programming community, this is often shortened to polymorphism.
* Subtyping (also called subtype polymorphism or inclusion polymorphism): when a name denotes instances of many different classes related by some common superclass. In the object-oriented programming community, this is often simply referred to as polymorphism.

The interaction between parametric polymorphism and subtyping leads to the concepts of variance and bounded quantification.

== See also ==

* [[Data type]]
* [[Duck typing]] for polymorphism without (static) types
* [[Polymorphic code]] (Computer virus terminology)
* [[System F]] for a lambda calculus with parametric polymorphism.
* [[Type class]]
* [[Type theory]]
* [[Virtual inheritance]]

== External links ==

* [https://en.wikipedia.org/wiki/Polymorphism_(computer_science) Polymorphism (computer science)] @ Wikipedia

[[Computer programming]]
[[Category:Computer science]]

@@ Line 7: / Line 7: @@
 There are several fundamentally different kinds of polymorphism:
-* Ad hoc polymorphism: when a function denotes different and potentially heterogeneous implementations depending on a limited range of individually specified types and combinations. Ad hoc polymorphism is supported in many languages using function overloading.
+* [[Ad hoc polymorphism]]: when a function denotes different and potentially heterogeneous implementations depending on a limited range of individually specified types and combinations. Ad hoc polymorphism is supported in many languages using [[function overloading]].
-* Parametric polymorphism: when code is written without mention of any specific type and thus can be used transparently with any number of new types. In the object-oriented programming community, this is often known as generics or generic programming. In the functional programming community, this is often shortened to polymorphism.
+* [[Parametric polymorphism]]: when code is written without mention of any specific type and thus can be used transparently with any number of new types. In the [[object-oriented programming]] community, this is often known as generics or [[generic programming]]. In the functional programming community, this is often shortened to polymorphism.
-* Subtyping (also called subtype polymorphism or inclusion polymorphism): when a name denotes instances of many different classes related by some common superclass. In the object-oriented programming community, this is often simply referred to as polymorphism.
+* [[Subtyping]] (also called subtype polymorphism or inclusion polymorphism): when a name denotes instances of many different classes related by some common superclass. In the [[object-oriented programming]] community, this is often simply referred to as polymorphism.
-The interaction between parametric polymorphism and subtyping leads to the concepts of variance and bounded quantification.
+The interaction between parametric polymorphism and subtyping leads to the concepts of [[Covariance and contravariance (computer science)|variance]] and [[bounded quantification]].
 == See also ==
 * [[Data type]]
 * [[Duck typing]] for polymorphism without (static) types
 * [[Polymorphic code]] (Computer virus terminology)
 * [[System F]] for a lambda calculus with parametric polymorphism.
 * [[Type class]]

Polymorphism (computer science) - Revision history

Karl Jones at 14:29, 20 September 2016

Karl Jones: Created page with "In programming languages and type theory, '''polymorphism''' (from Greek πολύς, ''polys'', "many, much" and μορφή, ''morphē'', "form, s..."