Re: [Caml-list] SDL2 bindings, testers and feedback welcome

["Daniel Bünzli" <daniel.buenzli@erratique.ch>]

Le mardi, 17 décembre 2013 à 07:11, Daniel Bünzli a écrit :
> * I used an 'a result = [ `Error | `Ok of 'a ] rather than an exception
> for functions that return error codes/null is error. I tend to lean
> on exceptionless designs but I'm still unsure whether it is a good
> idea that case. One of the problems is that SDL doesn't make a clear
> distinction (at the signature level *and* in the documentation)
> between programming errors (invalid_arg), exceptional errors
> (e.g. out of memory) and non-exceptional errors (e.g. could not
> access/setup a resource).

I found that in practice directly returning the string you get by SDL_GetError () in the `Error case is much more convenient. E.g. with the above type your bind looks like this:

let ( >>= ) x f = match x with  
| `Error -> `Error_msg (Sdl.get_error ())  
| `Error_msg _ as e -> e
| `Ok v -> f v



which is needlessly unconvenient. So I'm changing that type to  

'a result = [ `Error of string | `Ok of 'a ]

and you always directly get the result of Sdl.get_error () in the `Error case.  

Best,

Daniel