>> Local imports might be useful, though. Objective Caml 2.00 has finally
>> caved in and followed Standard ML in allowing expression-local modules.
>
>Standard ML does not allow this. One important aspect of the SML module
>system actually is its strong separation from the core language.
Not that old saw again...! Ocaml separates the two as well.
You're right, though. I meant expression-local imports, like
local open M
in ...
What Ocaml allows now is things like
let f x y =
let module M = struct ... y ... end
in ... M.y ...
No first-class doohickeys allowed, so it's really not that far from SML. I imagine
that it could be translated into SML along these lines (excuse my rusty SML):
structure M = struct ... val y = ref <something> ... end;
structure X =
struct
fun f(x,y) = M.y := y; ... !M.y ...
end;
Or maybe not. I'm not sure of the extent of the feature, but I get the impression
that it was a small change, mostly for programming convenience.
(In case anyone's interested.)
--FC
