Re: How users start programming in Emacs Lisp...

[Jean Louis <bugs@gnu.support>]

* Christopher Dimech <dimech@gmx.com> [2021-05-31 23:31]:
> I would like to be able to decide the name from the mini-buffer.
> How can that be done?

Here is the set of improved functions:

- your main buffer name is in variable `rcd-temp-buffer-name'; your
  main buffer name should be something unique, descriptive so that it
  can be destroyed easily (when necessarily) or followed up;

- run M-x rcd-temp-buffer-ask-name or bind it to key if you wish to
  get asked for sub-name

- use C-u prefix to get asked for mode

- if you have many temporary buffers you maybe wish to browse through
  such buffers, because they got their main name, the function M-x
  rcd-temp-buffer-next will go through such. Bind it to a simple key
  and you can press key and browse through temporary buffers quicker. 


;;;; ↝ RCD TEMPORARY BUFFERS

(defvar rcd-temp-buffer-mode-history nil)
(defvar rcd-temp-file-directory "~/tmp/")
(defvar rcd-temp-buffer-name "RCD TEMPORARY BUFFER")
(defvar rcd-temp-buffer-modes '(("adoc-mode" . "adoc")
				("emacs-lisp-mode" . "el")
				("lisp-mode" . ".lisp")
				("markdown-mode" . ".md")
				("org-mode" . "org")
				("sql-mode" . "sql")
				("fundamental-mode" . "txt")
				("html-mode" . "html")))

(defun rcd-temp-buffer (&optional name mode)
  "Generate new temporary buffer."
  (interactive "p")
  (let* ((format (concat "*" rcd-temp-buffer-name "%s%s*"))
	 (buffer (if name (format format ": " name) (format format "" ""))))
    (switch-to-buffer (generate-new-buffer buffer))
    (if current-prefix-arg
	(let* ((mode (completing-read
		      "Mode: "
		      (map-keys rcd-temp-buffer-modes) nil t nil
		      'rcd-temp-buffer-mode-history)))
	  (funcall (intern mode)))
      (funcall (intern (or mode "fundamental-mode"))))))

(defun rcd-temp-buffer-ask-name ()
  "Generate new temporary buffer by asking for buffer name."
  (interactive)
  (rcd-temp-buffer
   (read-from-minibuffer "Buffer name: ")))

(defun rcd-temp-file (&optional name mode)
  "Quickly open temporary file.
Using C-u as prefix will ask you for the mode of the file and
will influence the extension.

NAME may be provided programmatically.
MODE may be provided as string programmatically."
  (interactive)
  (let* ((mode (or mode
		   (if current-prefix-arg
		       (let* ((mode (completing-read
				     "Mode: "
				     (map-keys rcd-temp-buffer-modes) nil t nil
				     'rcd-temp-buffer-mode-history)))
			 mode)
		     "fundamental-mode")))
	 (file (concat rcd-temp-file-directory
		       (or name (format-time-string "%A-%B-%e-%Y-%T."))
		       (cdr (assoc-string mode rcd-temp-buffer-modes)))))
    (find-file file)
    (save-buffer)
    (funcall (intern mode))))

(defvar rcd-temp-buffer-list nil)

(defun rcd-temp-buffer-next ()
  (interactive)
  (unless rcd-temp-buffer-list
    (setq rcd-temp-buffer-list (reverse (rcd-list-matching-buffers rcd-temp-buffer-name))))
  (let ((rcd-buffer (pop rcd-temp-buffer-list))
	(buffer (current-buffer)))
    (if rcd-buffer
	(if (buffer-live-p rcd-buffer)
	    (switch-to-buffer rcd-buffer)
	  (rcd-temp-buffer-next))
      (message "No temporary buffers"))))

(defun rcd-temp-buffer-destroy-em ()
  (interactive)
  (kill-matching-buffers "RCD TEMPORARY BUFFER"))

(defun rcd-list-matching-buffers (query)
  "Return list of matching buffers."
  (let ((list))
    (mapc (lambda (buffer)
	    (when (string-match query (buffer-name buffer))
	      (push buffer list)))
	  (buffer-list))
    list))


-- 
Jean

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