Re: Determine object passed as argument

On 2026-04-11 15:14, Heime wrote:
> ----------------------------------------------------------------
> Can a function determine the object being passed as argument and
> print its name.  For instance that I passed if I pass fpln when
> calling (lana-du-fpln 'fpln).
> 
> (defun lana-du-fpln (datenstruk &optional bname)

In Emacs Lisp, you cannot directly get the variable name that was passed 
to a function, because arguments are evaluated before being passed. By 
the time datenstruk receives the value, the original variable name is 
lost.

(defun lana-du-fpln (datenstruk-symbol &optional bname)
   "Print the name of the symbol passed, then access its value."
   (message "Processing variable: %s" datenstruk-symbol)
   (let ((datenstruk (symbol-value datenstruk-symbol)))
     ;; Now work with datenstruk's value
     (message "Value: %S" datenstruk)))

Call it with quoted symbol: (lana-du-fpln 'fpln)

(defun lana-du-fpln (datenstruk-symbol &optional bname)
   "Print the name of the symbol passed, then access its value if bound."
   (message "Processing variable: %s" datenstruk-symbol)
   (if (boundp datenstruk-symbol)
       (let ((datenstruk (symbol-value datenstruk-symbol)))
         (message "Value: %S" datenstruk)
         ;; Your logic here
         )
     (message "Warning: %s is unbound (void variable)" 
datenstruk-symbol)))

"Warning: fpln is unbound (void variable)"
-- 
Jean Louis