Re: [PATCH] `affixation-function`: Allow only three-element lists

[Juri Linkov]

>>> +                        (cl-assert (or (not completions)
>>> +                                       (= 3 (length (car completions))))))

> I am looking at the `affixation-function` from the perspective of how the
> definition can be made as simple/predicatable as possible for the API user
> since there are other completion UIs and many completion tables which will
> make use of this. I treat the completion UI behind the API as a blackbox.

I completely agree that for `affixation-function` part of
the API is would be cleaner to document the input data as
only candidate + prefix + suffix.

But I don't agree with `cl-assert`.  It looks too odd.
Why to validate that the length of the first candidate is 3?
Why not to validate than the length of every candidate
is not more than 3?  Why not to validate that there are no nils
in the list?  Why not to validate there are only strings?  Etc.

IOW, I think it's responsibility of the API user to provide valid data
as documented.