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

[Jean Louis <bugs@gnu.support>]

* Christopher Dimech <dimech@gmx.com> [2021-05-30 20:22]:
> I am having some problem figuring out what the following does, having format 
> repeated twice.
> 
> (format format ": " name)

It could be all simpler, it just adds the sub-name to the main name.

M-x rcd-temp-buffer would create *RCD TEMPORARY BUFFER: 1*

but (rcd-temp-buffer "Lisp") would create *RCD TEMPORARY BUFFER: Lisp*

Myself I don't know why I made it so complex, but it just works and I
use temporary or scratch buffers that way often.

Simpler way to open temporary buffer is just:

C-x b NAME-OF-YOUR-BUFFER

but when function is tied to key binding it becomes simple, press F5
or other key how you bind it, and you are already in clean empty new
temporary buffer. Or invoke C-u prefix to be asked for the mode.

As Eduardo mentioned maybe it is good to keep those notes, but because
in my mind there is distinction on what is temporary and what is not,
for me it is fine that way as I use the database and it is trivial to
make a function to just open quickly buffer, write anything and have
it saved for future.

So I made this one...

(defun hyperscope-quick-emacs-lisp ()
  (interactive)
  (let* ((id (hlink-add-generic (concat "Emacs Lisp: " (rcd-timestamp-literate)) "" 50 33))
	 (template (rcd-db-get-entry "hlinktypes" "hlinktypes_template" 50 hs-db)))
    (when template
      (rcd-db-update-entry "hyobjects" "hyobjects_text" id template hs-db))
    (hyperscope-edit-with-mode id "hyobjects_text")))

The "name" of the note should be something quick:

(concat "Emacs Lisp: " (rcd-timestamp-literate)) ⇒ "Emacs Lisp: Sunday, May 30 2021, 22:21:26"

Function `hlink-add-generic' just adds generic object with type 50
(Emacs Lisp in description, text and report of the object) with the
parent node 33 which is "Emacs Lisp" set or category.

A type can have a template, why not, it is inserted as value of the
column "hyobjects_text", and finally edited in the last line.

Automatic saving is not a big deal, and automatic revision system
also.

What really matters is integration that brings speed to user without
thinking, and so the workflow is:

1. Press F5, edit Emacs Lisp (forget about anything else)

When editing database stuff, then things like byte compiling will not
work as it is not tied to buffer, but is not impossible to byte
compile and keep what is compiled in the database. I did not manage to
make it.

I am aware that little of this makes sense to people who edit mostly
files. Some functionality can be for files:

;;;; ↝ 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)
  (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-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)
    (auto-save-mode 1)
    (funcall (intern mode))))

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


Then calling `rcd-temp-file' with C-u prefix will create and save the
file with chosen mode, it will automatically generate name based on
the time stamp and it will be in the chosen mode, like:

/home/data1/protected/tmp/Sunday-May-30-2021-22:44:11.sql

Defining a key globally:

(global-set-key [f5] 'rcd-temp-file)

That could be one way to just press a key like F5 and to create a
note with the timestamp on a file system without thinking of its
file name, opening of file, saving, etc.


-- 
Jean

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