branch: externals/literate-scratch
commit c22a15e86acf28da716532c26ba1371574c8e979
Author: Sean Whitton <spwhit...@spwhitton.name>
Commit: Sean Whitton <spwhit...@spwhitton.name>
* literate-scratch: Import version 1.0
---
literate-scratch.el | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 134 insertions(+)
diff --git a/literate-scratch.el b/literate-scratch.el
new file mode 100644
index 0000000000..e3ac223bbb
--- /dev/null
+++ b/literate-scratch.el
@@ -0,0 +1,134 @@
+;;; literate-scratch.el --- Lisp Interaction w/ text paragraphs -*-
lexical-binding: t -*-
+
+;; Copyright (C) 2023-2024 Free Software Foundation, Inc.
+
+;; Author: Sean Whitton <spwhit...@spwhitton.name>
+;; Maintainer: Sean Whitton <spwhit...@spwhitton.name>
+;; Package-Requires: ((emacs "29.1"))
+;; Version: 1.0
+;; URL:
https://git.spwhitton.name/dotfiles/tree/.emacs.d/site-lisp/literate-scratch.el
+;; Keywords: lisp text
+
+;; This file 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.
+
+;; This file 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 this file. If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Variant Lisp Interaction mode for easier interleaving of paragraphs of
+;; plain text with Lisp code. This means you can have
+;;
+;; ;; This buffer is for text that is not saved ...
+;; ;; To create a file, visit it with C-x C-f and ...
+;;
+;; (here is some Lisp)
+;;
+;; Here is a plain text paragraph )( including some unmatched parentheses.
+;; Uh oh! Paredit won't like that.
+;;
+;; (here is some more Lisp)
+;;
+;; but (e.g.) Paredit won't complain about the unmatched parentheses.
+;; Indeed, the whole plain text paragraph is font-locked as a comment.
+;;
+;; If you use Paredit but want to be able to use *scratch* for both Lisp
+;; interaction and blocks of plain text, then this mode is for you.
+;; Also compatible with the `orgalist-mode' and `orgtbl-mode' minor modes.
+;;
+;; To enable this mode after installing this file, simply customise
+;; `initial-major-mode' to `literate-scratch-mode'.
+
+;;; News:
+
+;; Ver 1.0 2024/06/21 Sean Whitton
+;; Initial release.
+;; Thanks to Philip Kaludercic for review.
+
+;;; Code:
+
+(defun literate-scratch--extend (start end)
+ (save-excursion
+ (let ((res1
+ (and (goto-char start)
+ (not (looking-at paragraph-separate))
+ (and-let* ((new (car (bounds-of-thing-at-point 'paragraph))))
+ (and (< new start)
+ (setq start new)))))
+ (res2
+ (and (goto-char end)
+ (not (looking-at paragraph-separate))
+ (and-let* ((new (cdr (bounds-of-thing-at-point 'paragraph))))
+ (and (> new end)
+ (setq end new))))))
+ (and (or res1 res2)
+ (cons start end)))))
+
+(defun literate-scratch--propertize (start end)
+ (goto-char start)
+ (let ((start (1- start)))
+ (catch 'finish
+ (while t
+ (when-let* ((comment-start (nth 8 (syntax-ppss))))
+ (put-text-property (1- (point)) (point) 'syntax-table
+ (eval-when-compile
+ (string-to-syntax "!")))
+ (put-text-property comment-start (point) 'syntax-multiline t))
+ (forward-paragraph 1)
+ (backward-paragraph 1)
+ (unless (> end (point) start)
+ (throw 'finish nil))
+ (setq start (point))
+ (unless
+ (save-excursion
+ (catch 'done
+ (while t
+ ;; Examine the syntax of the paragraph's first char.
+ ;; If it's whitespace, we need to check the previous
+ ;; paragraph, to handle multiple paragraphs within a defun.
+ (let ((syn
+ (char-syntax
+ (char-after
+ ;; (1+ point) unless at end-of-buf or on first line
+ ;; of a paragraph beginning right at beg-of-buf.
+ (if (looking-at "\\`[[:space:]]*[^[:space:]\n]")
+ (point)
+ (1+ (point)))))))
+ (cond ((bobp) (throw 'done (memq syn '(?\( ?<))))
+ ((memq syn '(?\( ?<)) (throw 'done t))
+ ((not (eq syn ?\s)) (throw 'done nil))))
+ (backward-paragraph 1))))
+ (put-text-property (point) (1+ (point)) 'syntax-table
+ (eval-when-compile
+ (string-to-syntax "!"))))
+ (forward-paragraph 1))))
+ ;; Now also call the usual `syntax-propertize-function' for this mode.
+ (elisp-mode-syntax-propertize start end))
+
+;;;###autoload
+(define-derived-mode literate-scratch-mode lisp-interaction-mode
+ "Lisp Interaction"
+ "Variant `lisp-interaction-mode' designed for the *scratch* buffer.
+
+Paragraphs that don't start with `(' or `;' are treated as block comments.
+This makes it easier to interleave paragraphs of plain text with Lisp.
+
+You can enable this mode by customizing the variable `initial-major-mode'
+to `literate-scratch-mode'."
+ (add-hook 'syntax-propertize-extend-region-functions
+ #'syntax-propertize-multiline t t)
+ (add-hook 'syntax-propertize-extend-region-functions
+ #'literate-scratch--extend t t)
+ (setq-local syntax-propertize-function #'literate-scratch--propertize))
+
+(provide 'literate-scratch)
+
+;;; literate-scratch.el ends here
