contravariance

English

Etymology

From contra- +‎ variance.

Pronunciation

• Audio (US):

  (file)

Noun

contravariance (countable and uncountable, plural contravariances)

1. (object-oriented programming) The reversal of the order of data types acted upon by an operator.

   Coordinate term: covariance

   • 2005, Jesse Liberty, Visual C# 2005: A Developer's Notebook, O'Reilly Media, →ISBN, page 47:

     I get why with covariance I can return a Dog (a Dog is a Mammal), but why does contravariance work the other way? Shouldn't it accept a derived type when it expects a base type? Contravariance is consistent with Postel's Law: […]

2. (category theory) A functor which reverses composition.
3. (linear algebra) Of vectors, the property of scaling inversely with a change of basis, as opposed to covariance.

Related terms

• contravariant

Translations

reversal of the order of data types acted upon by an operator

• Chinese:

  Mandarin: 逆變 / 逆变 (zh) (nìbiàn)

• Finnish: kontravarianssi
• French: contravariance (fr) f
• German: Kontravarianz f
• Kazakh: контраварианттық (kontravarianttyq)
• Portuguese: contravariância f
• Romanian: contravarianță f
• Russian: контравариантность (ru) f (kontravariantnostʹ)

functor which reverses composition

• Finnish: kontravarianssi
• German: Kofunktor m

Further reading

• covariance and contravariance (computer science) on Wikipedia.Wikipedia
• covariance and contravariance of vectors on Wikipedia.Wikipedia

French

Pronunciation

• Audio:

  (file)

Noun

contravariance f (plural contravariances)

1. (object-oriented programming) contravariance

Further reading

• “contravariance”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.