Re: feature/type-hierarchy 8a63e50036f 1/5: * Define 'cl--type-hierarchy' and compute 'cl--typeof-types' from it

[Andrea Corallo <acorallo@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>>>>> The original was inconsistent on this,
>>>>> Maybe that was an oversight.
>>>>> Do you remember which inconsistency you had noticed in this respect?
>>>> I remember (symbol-with-pos symbol atom) (symbol atom), there might have
>>>> been others.
>>> I think I see.  By "leaf" I really meant "non abstract": both `symbol`
>>> and `symbol-with-pos` describe *the* type of some objects (IOW `type-of`
>>> can return that symbol), as opposed to things like `sequence`, `list`,
>>> atom`, `number-or-marker`, ...
>> Ah!  Mmmh then is not so simple...
>
> It's not complicated either, but I guess what you mean is that the DAG
> doesn't have enough info, and there I can I agree (which is why in the
> previous code we generated the DAG from `cl--typeof-types` instead of
> the reverse 🙂).

My 2 cents.  I see `cl--typeof-types` for the nature of its non trivial
format and caveats as an internal representation that was layout-ed like
it is for some specific internal machinery.  I find more convenient how
we can express the DAG now (and generate `cl--typeof-types`
automatically from it).

  Andrea