Re: [Caml-list] ignore semantics

[Francois Berenger <berenger@riken.jp>]

On 12/17/2012 09:11 PM, Philippe Veber wrote:
> Dear all,
>
> This is a rather minor issue, but I was surprised by the following
> answers of the interpreter:
>
>          OCaml version 4.00.1
>
> # ignore succ;;
> Warning 5: this function application is partial,
> maybe some arguments are missing.
> - : unit = ()
> # (fun _ -> ()) succ;;
> - : unit = ()

Didn't you intended to write

ignore (succ 0);;

(or with any other integer instead of 0) ?

In that case it compiles but I don't get what the code
is intended to do.

Regards,
F.

> I naively used to think the two expressions were equivalent. Reading
> pervasives.mli, I found that ignore is a primitive:
>
> external ignore : 'a -> unit = "%ignore"
>
> which means it is treated as a special case. Just for curiosity, what is
> the rationale for the warning in the first case?
>
> Cheers,
>    Philippe.
>
>