On 28 March 2016 at 10:07, Gabriel Scherer <gabriel.scherer@gmail.com>
wrote:

> (* the difference by "(type a) ..." and "type a . ..." is that the latter
>    allows polymorphic recursion (just as "'a . ..."), so this example fails
>    with just (type a) *)
>

So here's a question which has been nagging me for a while: is there any
occasion where one may prefer to use the `(type a)` or the `'a.` forms over
the `type a.` (apart for syntactical reasons)? If there is I'd be really
interested in seeing an example, for I can't come up with one (especially
for `(type a)`). If there aren't, what are the obstacles to turn the `(type
a)` syntax into a synonymous to the `type a.` syntax? (I'm guessing that
the `'a.` variant would be significantly harder).