Estimate elisp object memory usage

estimate-size.el

;; This code was created by chatgpt

(defun estimate-list-size (list)
  "Estimate the memory size of LIST in bytes."
  (let ((size 0))
    (while list
      (setq size (+ size (estimate-object-size (car list))))
      (setq size (+ size 8))  ; Approximate overhead for cons cell
      (setq list (cdr list)))
    size))

(defun estimate-string-size (string)
  "Estimate the memory size of STRING in bytes."
  (string-bytes string))

(defun estimate-buffer-size (buffer)
  "Estimate the memory size of BUFFER in bytes."
  (with-current-buffer buffer
    (buffer-size)))

(defun estimate-object-size (obj)
  "Estimate the memory size of OBJ in bytes."
  (cond
   ((stringp obj) (estimate-string-size obj))
   ((listp obj) (estimate-list-size obj))
   ((bufferp obj) (estimate-buffer-size obj))
   ;; Add more cases as needed
   (t 0)))  ; Default case for unsupported types

;; Example usage:
(estimate-object-size "This is a test string")  ; Estimate size of a string
(estimate-object-size '(1 2 3 4))              ; Estimate size of a list
(estimate-object-size (current-buffer))        ; Estimate size of the current buffer