The comment describing FOLDABLE is accurate, btw. Unfortunately, the issue with keywords is a bit more complicated. I'm not comfortable considering symbols that appear in source forms as literal. Moreover, even if they were literal values, it seems strange to disallow unintern, but allow (setf symbol-value) or (setf symbol-function).
The comment describing FOLDABLE is accurate, btw. Unfortunately, the issue with keywords is a bit more complicated. I'm not comfortable considering symbols that appear in source forms as literal. Moreover, even if they were literal values, it seems strange to disallow unintern, but allow (setf symbol-value) or (setf symbol-function).