Re: [Caml-list] Error: The type abbreviation t is cyclic while defining submodules

[Gabriel Scherer <gabriel.scherer@gmail.com>]

P.S.: Note that "nonrec" is only in definitions (struct .. end) and
signatures (sig .. end), not in equations such as "with type t = t"
which are a different construct, interpreted recursively -- not the
best choice for consistency, but well.

On Fri, Jun 10, 2016 at 4:03 PM, Gabriel Scherer
<gabriel.scherer@gmail.com> wrote:
> This is
>
>   type nonrec t = t
>
> which has been introduced in 4.02, after some years of internal usage
> of (a syntax preprocessor implementing) it internally in Jane Street.
>
> On Fri, Jun 10, 2016 at 4:00 PM, Sébastien Hinderer
> <Sebastien.Hinderer@inria.fr> wrote:
>> Dear all,
>>
>> Assume the following code in a file points.ml:
>>
>> type t = float * float
>>
>> let compare = Pervasives.compare
>>
>> (* Other functions on points *)
>>
>> module OrderedPoints : Set.OrderedType with type t = t = struct
>>   type t = t
>>   let compare = compare
>> end
>>
>> module PointSet : Set.S with type t = t = Set.Make(OrderedPoints)
>>
>>
>> The line
>>   type t = t
>> yields the above mentionned error.
>>
>> Is there a way to let the compiler know that the t appearing after the
>> "=" sign refers to the type defined at points.ml top level?
>>
>> Thanks!
>>
>> Sébastien.
>>
>> --
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