Re: [Caml-list] Scripting in ocaml

[Philippe Wang <lists@philippewang.info>]

Serge Aleynikov a écrit :

> What I meant by "strict typing" was performing type checks *at runtime*, 
> i.e. that there are no unsafe operations.
> 
> Say, as an example, doing type checks of function arguments at runtime:
> 
> let f = fun i when is_integer (i) -> i
>           | x when is_float   (x) -> int_of_float x;;
> 
> (raising Bad_match of some sort if neither one of the two guards pass)
> 
> Direct application of this could be for making the Marshal/Unmarshal 
> modules more safe when marshaling data over files/sockets between 
> applications written in heterogeneous languages.

If you want to do that, use Lisp...
Or use sum types...
type t = Int of int | Float of float | ...

OCaml forgets types at runtime !
This means that you can't know without a huge cost (cf. SafeUnmarshal 
costs), because what you can do in O(1) is to know whether a value is an 
int or a pointer...

If OCaml is particularly efficient, it's probably mostly because of that!
...

Cheers,

--
Philippe Wang
   mail(at)philippewang.info