Lars Ingebrigtsen <larsi@gnus.org> writes:

> Philip Kaludercic <philipk@posteo.net> writes:
>
>> Another idea could be to take inspiration from Guile's "Sandboxed
>> Evaluation"[0] and provide a "safe subset" of Elisp that can be
>> evaluated (with some additional checks).
>>
>> E.g. the following would allow evaluating `add-to-list' if the list if
>> safe and the value is self-evaluating:
>
> Oh, that's a good idea.  I wonder whether anybody's written an
> interpreter for a "safe" version of Emacs Lisp -- then people could put
> `if' statements etc also into these files.

There is unsafep, but that is too strict for what we want.  E.g.

  (unsafep '(setq tab-width 3)) ;; => (global-variable tab-width)

even though we would want this to work.  I've attached an incomplete
sketch of how this could look like