functor

Fetched 2026-10-26 (cache).

Datamuse reports no synonyms or antonyms for this word.

Noun

1. {{lb|en|grammar}} A [[function word]].
2. {{lb|en|object-oriented programming}} A [[function object]].
3. {{lb|en|category theory}} A [[category]] [[homomorphism]]; a [[morphism]] from a source category to a target category which maps objects to objects and arrows to arrows (either [[covariant]]ly or [[contravariant]]ly), in such a way as to preserve morphism [[composition]] and [[identity|identities]]. {{C|en|Functions}}
4. {{lb|en|functional programming}} A structure allowing a [[function]] to apply within a [[generic type]], in a way that is conceptually similar to a functor in category theory.

Source: Wiktionary · CC BY-SA 4.0 (Wiktionary dump) · cached copy, not a rewrite.