emacs/lisp/emacs-lisp/eieio-datadebug.el

;;; eieio-datadebug.el --- EIEIO extensions to the data debugger.  -*- lexical-binding:t -*-

;; Copyright (C) 2007-2025 Free Software Foundation, Inc.

;; Author: Eric M. Ludlam <zappo@gnu.org>
;; Keywords: OO, lisp
;; Package: eieio

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:
;;
;; Extensions to data-debug for EIEIO objects.
;;

(require 'eieio)
(require 'data-debug)

;;; Code:

(declare-function data-debug/eieio-insert-slots "eieio-datadebug"
                  (obj eieio-default-superclass))

(defun data-debug-insert-object-slots (object prefix)
  "Insert all the slots of OBJECT.
PREFIX specifies what to insert at the start of each line."
  (let ((attrprefix (concat (make-string (length prefix) ? ) "] ")))
    (data-debug/eieio-insert-slots object attrprefix)))

(defun data-debug-insert-object-slots-from-point (point)
  "Insert the object slots found at the object button at POINT."
  (let ((object (get-text-property point 'ddebug))
	(indent (get-text-property point 'ddebug-indent))
	start)
    (end-of-line)
    (setq start (point))
    (forward-char 1)
    (data-debug-insert-object-slots object
				    (concat (make-string indent ? )
					    "~ "))
    (goto-char start)))

(defun data-debug-insert-object-button (object prefix prebuttontext)
  "Insert a button representing OBJECT.
PREFIX is the text that precedes the button.
PREBUTTONTEXT is some text between PREFIX and the object button."
  (let* ((start (point))
         (end nil)
         (str (cl-prin1-to-string object))
         (class (eieio-object-class object))
         (tip (format "Object %s\nClass: %S\nParent(s): %S\n%d slots"
                      (eieio-object-name-string object)
                      class
                      (eieio-class-parents class)
                      (length (eieio-class-slots class))
                      ))
         )
    (insert prefix prebuttontext str)
    (setq end (point))
    (put-text-property (- end (length str)) end 'face 'font-lock-keyword-face)
    (put-text-property start end 'ddebug object)
    (put-text-property start end 'ddebug-indent(length prefix))
    (put-text-property start end 'ddebug-prefix prefix)
    (put-text-property start end 'help-echo tip)
    (put-text-property start end 'ddebug-function
		       'data-debug-insert-object-slots-from-point)
    (insert "\n")))

;;; METHODS
;;
;; Each object should have an opportunity to show stuff about itself.

(cl-defmethod data-debug/eieio-insert-slots ((obj eieio-default-superclass)
                                             prefix)
  "Insert the slots of OBJ into the current DDEBUG buffer."
  (let ((inhibit-read-only t))
    (data-debug-insert-thing (eieio-object-name-string obj)
			     prefix
			     "Name: ")
    (let* ((cv (eieio--object-class obj)))
      (data-debug-insert-thing (eieio--class-name cv)
			       prefix
			       "Class: ")
      ;; Loop over all the public slots
      (let ((slots (eieio--class-slots cv)))
	(dotimes (i (length slots))
          (let* ((slot (aref slots i))
                 (sname (cl--slot-descriptor-name slot))
                 (i (eieio--class-slot-initarg cv sname))
                 (sstr (concat (symbol-name (or i sname)) " ")))
            (if (slot-boundp obj sname)
                (let* ((v (eieio-oref obj sname)))
                  (data-debug-insert-thing v prefix sstr))
              ;; Unbound case
              (data-debug-insert-custom
               "#unbound" prefix sstr
               'font-lock-keyword-face)
              )))))))

;;; Augment the Data debug thing display list.
(data-debug-add-specialized-thing #'eieio-object-p
				  #'data-debug-insert-object-button)

;;; DEBUG METHODS
;;
;; A generic function to run DDEBUG on an object and popup a new buffer.
;;
(cl-defmethod data-debug-show ((obj eieio-default-superclass))
  "Run ddebug against any EIEIO object OBJ."
  (data-debug-new-buffer (format "*%s DDEBUG*" (eieio-object-name obj)))
  (data-debug-insert-object-slots obj "]"))

(provide 'eieio-datadebug)

;;; eieio-datadebug.el ends here