Re: [Caml-list] The rec/nonrec debate

[Dario Teixeira <darioteixeira@yahoo.com>]

Hi,

> I agree that making recursitivy more explicit is... well... more explicit :)
> But I wonder if, in this case, this is truly relevant. In fact, when I look at
> OCaml programs, I see many recursive types and very few type shadowing.
> That is, making types non recursive would add some "rec" or "nonrec"
> keywords everywhere just to avoid a type alias in a rare case. From
> readability point of view, I'm not sure it's a good deal. In the programs
> I know, the ratio seems to be something like 70/30 for nonrec/rec function
> while, this time, shadowing is quite often used. Here, explicit "rec" allows
> us to avoid more "nonrec" elsewhere to continue using shadowing.


In my opinion, even if a statistical analysis of a large corpus of OCaml code
were to show that shadowing is much rarer than recursive type definitions,
the case could still be made that having nonrec as the common default
for both types and values would still be preferable for a) consistency, and
b) avoiding the need to have both "rec" and "nonrec" as keywords.

On a tangent, I also find it interesting that Mezzo has adopted the Haskell
convention of type declarations being head-first.  Not that I disagree: in fact,
one could argue there is some inconsistency in the ML/OCaml convention
of declaring types head-last and values head-first...

Cheers,
Dario