On 23 Sep 2024, at 12:13, Marc Nieper-Wißkirchen <xxxxxx@gmail.com> wrote:

>>   R7RS Large will probably make weaknesses in collection like this implementation-specified, so conforming impls will have to document if they can’t collect symbols.
>
> Has this been discussed already?

<https://codeberg.org/scheme/r7rs/issues/105>

> Firstly, it doesn't make sense to use keys without locations, as I tried to explain.  Secondly, SRFI 254 does not ban them but leaves it open.
>

> It is like saying strings are not important for, say, "+".  R7RS leaves it open what happens when you evaluate (+ 1 "zwei").

The difference between that case and this is that R7RS also clearly states a set of values for which the result of + is not ‘left open’.

> I still fail to understand in what sense it is not strong enough.  It lists types that are guaranteed to denote locations or sequences of locations.  What else would be needed?

The list is non-exhaustive. It says ‘such as’. Clearly, there are ‘objects’ which do not denote locations.

Daphne