Re: Emacs object type hierarchy

[Gerd Möllmann]

Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> Andrea Corallo <acorallo@gnu.org> writes:
>
>> Hi Gerd,
>
> Hi ANdrea.
>
>>
>> Thanks I've added fixnum, bignum, keyword, struct and class.  I'm just
>> not sure how to integrate the nil vs. () in such representation.
>
> Hm, yeah, maybe I was confused.  Was there already the lisp <- null, and
> lisp <- cons edge, previously?  That's what I meant.  Would "null" also
> be subtype of symbol?  (Asumming the arrows show subtype relations.)

BTW, depending on what you want to do, maybe looking at SBCL is worth
it.  SBCL has done a lot of work on types, also for the benefit of the
compiler.

  https://github.com/sbcl/sbcl

See src/code/type.lisp, for example.  It's in the public domain.