Archives of the Caml mailing list > Message from Dario Teixeira

Browse thread

Re: [Caml-list] Subtyping structurally-equivalent records, or something like it?

Dario Teixeira
- Sylvain Le Gall
  - AUGER Cédric
  - Sylvain Le Gall
    - rossberg@m...
      - Sylvain Le Gall
        
        Fabrice Le Fessant
      - Goswin von Brederlow
        
        rossberg@m...
        
        Goswin von Brederlow
    - Edgar Friendly
      - Goswin von Brederlow
      - Yaron Minsky

Date:	-- (:)
From:	Dario Teixeira <darioteixeira@y...>
Subject:	Re: [Caml-list] Subtyping structurally-equivalent records, or something like it?

Hi,

>  type kinematic = { lin: Vec.t; ang: Vec.t }
>
> Which I've been using to represent a medley of physical attributes (force, > momentum, velocity, etc.).

I second Stéphane's suggestion of using phantom types; moreover,
I recommend you read an article that discusses them to some detail
and covers their use for precisely this sort of problem:
http://camltastic.blogspot.com/2008/05/phantom-types.html

Cheers,
Dario Teixeira