For anyone reading &quot;functor&quot; and moving on, this (<a href="http:&#x2F;&#x2F;www.catonmat.net&#x2F;blog&#x2F;on-functors&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.catonmat.net&#x2F;blog&#x2F;on-functors&#x2F;</a>) is a great post discussing how the term is used in a variety of languages.