Re: [boost] Re: function.hpp: the word Functor

From: James Dennett (jdennett_at_[hidden])
Date: 2001-05-07 10:39:20

John Max Skaller wrote:
> 
> It seems that function.hpp contains a word 'Functor',
> use to describe a class emulating a function.
> 
> The best word to use is Functoid (or even Function!!).
> The entity described is NOT a functor.
> That word has a precise technical meaning in mathematics:
> a functor is a structure preserving map.
> The terminology is used extensively in computer science literature,
> and is even a keyword in SML (where the use really is intended
> to provide a model of a functor).

As a mathematician who defected to the programming world,
I understand your concern.  Unfortunately "functor" is already
in use in the C++ world at least to describe a functoid, and
there's certainly much precendent for C++ to use words in other
than their mathematical roles (for example, std::vector does
not support addition or multiplication by scalars, and might
arguably more reasonably have been called std::array).

-- James Dennett <jdennett_at_[hidden]>