Re: [Caml-list] polymorphic sets?

[Yaron Minsky <yminsky@janestreet.com>]

Core_kernel's maps and sets solve this problem, and address Gabriel's
concern as well, by providing type witnesses that distinguish maps
built with different comparators.  There's an introduction to the use
of these modules here:

<https://realworldocaml.org/v1/en/html/maps-and-hash-tables.html>

and you can see the current APIs here:

<https://github.com/janestreet/core_kernel/blob/master/src/core_map.mli>

Sets are handled similarly.For sure, better inlining (as is coming in
Flambda!) can make this approach better.

y

On Tue, Sep 29, 2015 at 9:56 AM, Jesper Louis Andersen
<jesper.louis.andersen@gmail.com> wrote:
>
> On Tue, Sep 29, 2015 at 2:58 PM, Gabriel Scherer <gabriel.scherer@gmail.com>
> wrote:
>>
>> Note that the polymorphic sets (or maps) are less statically-safe than
>> their functorized counterpart, because they are parametrized over their
>> comparison function at creation time
>
>
> The only point in time I've had troubles is when you have a map where its
> values and keys range over a type that can recursively contain that map of
> the same type. This required a polymorphic compare (from Core) to pull off.
>
>
> --
> J.