Functor

The word functor was first used by the philosopher Rudolf Carnap (1934) to designate functions that deliver not only truth values but terms , i.e. not just predicates . The application of the functor is therefore not a proposition . Today it is used:

• in logic , see functor (logic)
• in mathematical category theory as a structurally compatible mapping between categories. See functor (math)
• in computer science in connection with:
  • object-oriented programming as another word for functional object
  • the programming language Prolog as a combination of a function symbol and an arity (for example "compose / 2" names the activations of the symbol "compose" with exactly two arguments)
  • the programming language Standard ML

This is a disambiguation page for differentiating between several terms identified with the same word.