Good point on _. A suffix works. ^ suggests the mnemonic "it comes from above."

(defmacro sm/test (x y)
  (with-uninterned-symbols
   `(let ((foo^ ,x)
          (bar^ ,y))
      (list :args `(,foo^ . ,bar^)
            :add   (+ foo^ bar^)
            :sub   (- foo^ bar^)
            :mul   (* foo^ bar^)
            :div   (/ foo^ bar^)))))

On Sun, Feb 9, 2025 at 3:33 AM Tassilo Horn <tsdh@gnu.org> wrote:
Ship Mints <shipmints@gmail.com> writes:

> I prefer a hat ^ prefix as it is easier to read, rather than a dollar
> $ suffix which seems muddled to my eye.

I don't mind what character to use (the macro could even take it as an
argument) but I'd prefer using a suffix simply because there's already
the special prefix _ indicating to the byte-compiler that this variable
is not used intentionally.  You might want to use that capability when
your macro expands to a function which needs to have a certain signature
but your implementation doesn't use all arguments, for example.

Bye,
Tassilo