Emacs: Upcase Sentences 🚀

Here's emacs command to fix letter case of sentences. That is, any letter after a period (full stop), question mark, exclamation, will be capitalized.

This saves you typing. You can keep typing without pressing Shift to type uppercase letters. After you finished typing a paragraph, you can press a button and have the letters capitalized.

put this in your Emacs Init File:

(defun xah-upcase-sentence ()
  "Upcase first letters of sentences of current block or selection.

URL `http://xahlee.info/emacs/emacs/emacs_upcase_sentence.html'
Version: 2020-12-08 2020-12-24 2021-08-13 2022-05-16 2022-08-27"
  (interactive)
  (let (xp1 xp2)
    (let ((xbds (xah-get-bounds-of-block-or-region))) (setq xp1 (car xbds) xp2 (cdr xbds)))
    (save-restriction
      (narrow-to-region xp1 xp2)
      (let ((case-fold-search nil))
        ;; after period or question mark or exclamation
        (goto-char (point-min))
        (while (re-search-forward "\\(\\.\\|\\?\\|!\\)[ \n]+ *\\([a-z]\\)" nil :move)
          (upcase-region (match-beginning 2) (match-end 2))
          (overlay-put (make-overlay (match-beginning 2) (match-end 2)) 'face 'highlight))
        ;; after a blank line, after a bullet, or beginning of buffer
        (goto-char (point-min))
        (while (re-search-forward "\\(\\`\\|• \\|\n\n\\)\\([a-z]\\)" nil :move)
          (upcase-region (match-beginning 2) (match-end 2))
          (overlay-put (make-overlay (match-beginning 2) (match-end 2)) 'face 'highlight))
        ;; for HTML. first letter after tag
        (when
            (or
             (eq major-mode 'xah-html-mode)
             (eq major-mode 'html-mode)
             (eq major-mode 'sgml-mode)
             (eq major-mode 'nxml-mode)
             (eq major-mode 'xml-mode)
             (eq major-mode 'mhtml-mode))
          (goto-char (point-min))
          (while
              (re-search-forward "\\(<title>[ \n]?\\|<h[1-6]>[ \n]?\\|<p>[ \n]?\\|<li>[ \n]?\\|<dd>[ \n]?\\|<td>[ \n]?\\|<br ?/?>[ \n]?\\|<figcaption>[ \n]?\\)\\([a-z]\\)" nil :move)
            (upcase-region (match-beginning 2) (match-end 2))
            (overlay-put (make-overlay (match-beginning 2) (match-end 2)) 'face 'highlight))))
      (goto-char (point-max)))
    (skip-chars-forward " \n\t")))

requires package Emacs: xah-get-thing.el