Re: [Ocaml-lib-devel] ExtLib v0.1

[Nicolas C. <war...@fr...>]

> Good suggestions.
>
> Another issue: I see (at least) two philosophies of exception naming.
>
> (1) The standard library only defines a few, and uses string arguments (to
> Failure and Invalid_argument) for specifics.
>
> (2) Nicolas's collection uses more numerous and specific exceptions:
>     Invalid_index
>     Invalid_string
>     No_such_element
>     ...
>
> I guess I'm used to the first approach, and the generality hasn't been
> a problem.  I've almost always been able to write something like
>     try ... with Failure _ -> ...
> and often just
>     try ... with _ -> ...
> rather than being more specific.  What has been the experience of
> others on this list?

We have already been discussing about that ( see the list archives ).
The probleme here is that you cannot enclose a large blocs of code within
try...with because catching Failure _ or even worst _ can be a very bad
thing. So most of the time I suppose you're doing something like :

let i = (try int_of_string s with _ -> raise MyException) in
....

and then MyException is catched by the up/calling function.  This would be
easier to have int_of_string directly raising your exception. Exceptions are
made to propagate, and Failure / Invalid_arguments are good for either
immediate catching or no-catching at all .

Nicolas Cannasse