Le 25/10/2020 à 21:53, Marc Nieper-Wißkirchen a écrit :
> If you allow me to comment on this:
>
> Whether a portable implementation is possible or not is one thing (and
> doesn't have to be a show stopper), but it is quite another thing if
> the specification cannot make any guarantees in order to allow at
> least non-portable implementations on most existing and future Schemes
> (which, in this case, has to take nanboxing into account).

Then  maybe we  could  propose that  'nan-payload'
returns some  marker data that  may or may  not be
the  51 bits,  letting  implementations to  decide
what is the best choice for them.

Conversely to be useful in calculations I think we
need to  be able to  add a function to  create NaNs
with a given marker.

Emmanuel