CONTRAVARIANCE Meaning and
Definition
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Contravariance is a concept in programming languages, particularly in type systems, that describes the relation between types when considering subtyping and function compatibility. It is the opposite of variance, which refers to the covariance relationship.
In a type system, contravariance refers to a type relationship where a function or method parameter is allowed to be of a more general (or "supertype") than the type originally specified. This means that, in a contravariant type system, a function that expects a more specific (or "subtype") argument type can also accept an argument of a more general type. This subtyping relationship is typically denoted with a "-<:" symbol.
Contravariant types can be seen as opposite to covariant types, where a function parameter is required to be of a more specific type than the one originally specified. The key idea behind contravariance is that functions or methods that operate on more general types can still accept more specific types because they can be considered as compatible with the general type requirements.
Contravariance is most commonly used in functional programming and object-oriented programming languages, where it allows for increased flexibility and code reuse. It ensures that functions and methods can be applied to a wider range of input types without sacrificing type safety. By understanding contravariance, programmers can design more versatile and flexible codebases and libraries.
Common Misspellings for CONTRAVARIANCE
- xontravariance
- vontravariance
- fontravariance
- dontravariance
- cintravariance
- ckntravariance
- clntravariance
- cpntravariance
- c0ntravariance
- c9ntravariance
- cobtravariance
- comtravariance
- cojtravariance
- cohtravariance
- conrravariance
- confravariance
- congravariance
- conyravariance
- con6ravariance
- con5ravariance
Etymology of CONTRAVARIANCE
The word "contravariance" is formed by combining the prefix "contra-" meaning "against" or "opposite", and the word "variance", which is derived from the Latin word "variantia", meaning "difference" or "variation".
In computer science, "contravariance" refers to the relationship between different types in a programming language when it comes to subtyping or type compatibility. It describes a property where types can be replaced by more general (or "contravariant") types without affecting the correctness of a program. The term was introduced and popularized in the context of type theory and programming languages, but its etymology is rooted in the combination of the aforementioned words.
