On 19 Aug 2021, at 18:03, Marc Nieper-Wißkirchen <xxxxxx@gmail.com> wrote:

> Thanks for the explanation.  When we look at the future, it would be good if istring? is guaranteed to return #t for string literals.  This way, we would get rid of two lexical syntaxes otherwise needed (and which would be a wart in the Scheme standard because string literals can also be considered immutable by portable code).  I think this is an important point.

Disagreement from my side, at least as long as implementations exist which actually allow mutating literals. (This is a majority of them at the moment! https://doc.scheme.org/surveys/ImmutableStrings/)

istring? should never return #t on a string that might change under my nose later.

Daphne