Emacs: Toggle Letter Case
Emacs has these commands for changing letter case. They are:
There are also “region” versions for each:
(Note: for elisp programing, there are also these functions:
One problem with these commands is that you need to move your cursor to the beginning of the word first. For example, if you have the text “THat”, and your cursor is on the “a”, and you Alt+x
downcase-word, but it doesn't do anything because it only start at the cursor point to end of word. It would be nice if it'll just automatically perform the operation on the whole word.
Another problem is that it does not consider the final result. For example, if you have “oncE upon a time …”, and you select the whole sentence and Alt+x
upcase-initials-region, it becomes “OncE Upon A Time …”. Note the capital E is not automatically lowered. For elisp programing, the orthogonal precision is nice, but as user commands, it is better to change the whole sentence.
Also, these commands have a “-word” and “-region” variants. You have to chose which one to use. It would be nice if emacs automatically choose the right command depending whether there is text selection.
Here's a command that combines letter-case commands into one.
(defun xah-toggle-letter-case () "Toggle the letter case of current word or text selection. Always cycle in this order: Init Caps, ALL CAPS, all lower. URL `http://ergoemacs.org/emacs/modernization_upcase-word.html' Version 2017-04-19" (interactive) (let ( (deactivate-mark nil) $p1 $p2) (if (use-region-p) (setq $p1 (region-beginning) $p2 (region-end)) (save-excursion (skip-chars-backward "[:alnum:]-_") (setq $p1 (point)) (skip-chars-forward "[:alnum:]-_") (setq $p2 (point)))) (when (not (eq last-command this-command)) (put this-command 'state 0)) (cond ((equal 0 (get this-command 'state)) (upcase-initials-region $p1 $p2) (put this-command 'state 1)) ((equal 1 (get this-command 'state)) (upcase-region $p1 $p2) (put this-command 'state 2)) ((equal 2 (get this-command 'state)) (downcase-region $p1 $p2) (put this-command 'state 0)))))
Give it a easy key, such as Ctrl+9. [see Emacs: How to Define Keys]
Toggle Previous Letter Case
Another issue, not related to emacs, but related to efficiency of Shift key, is that the conventional way of typing capital letter using the Shift key is inefficient. You have to hold it, type a letter, then release it. (For detail about the Shift key problem, see Banish Shift Key.)
A better way to type capital letters, is to have a designated key, so that, when pressed, the previous letter is capitalized. (alternatively, press this key first, then next letter key pressed is capitalized. This is like a ⎄ Compose key. [see Alt Graph Key, Compose Key, Dead Key] )
This is better because:
- No more awkward holding key problem.
- Simpler model. Type a letter key, then press another key to capitalize it.
Here's the command.
(defun xah-toggle-previous-letter-case () "Toggle the letter case of the letter to the left of cursor. URL `http://ergoemacs.org/emacs/modernization_upcase-word.html' Version 2015-12-22" (interactive) (let ((case-fold-search nil)) (left-char 1) (cond ((looking-at "[[:lower:]]") (upcase-region (point) (1+ (point)))) ((looking-at "[[:upper:]]") (downcase-region (point) (1+ (point))))) (right-char)))
For this to work, you need to assign a easy key for this. For example, if you have a ergodox keyboard [see Best Keyboards for Emacs], set it to a thumb key.
If you have a normal PC keyboard, you could set the right Shift to something such as F20, then bind F20 to the command.
For how to remap keys in OS, see: Keyboard Tutorial: Layout, Keybinding, Key Macro ⌨.
Emacs Text Transform Under Cursor
- elisp wrapper + Python Ruby …
- Toggle Letter Case
- Title Case
- Upcase Sentences
- Cycle Space Hyphen Underscore
- Escape Quotes
- Quote Lines
- Spaces to New Lines
- Change Brackets/Quotes
- Remove Accent Marks
- Convert Straight/Curly Quotes
- Convert English/Chinese Punctuations
- Color Conversion (RGB, HSL, HSV)
- Decimal to Hexadecimal
- Replace Greek Letter Names to Unicode
- Twitterfy Text
- Toggle line wrap
- Clean White Space
- Simple Changes Emacs Should Adopt
- Why Emacs Keys are Painful
- Problems of the Scratch Buffer
- M-key Notation vs Alt+key Notation
- Menu Problem
- Mode Line Problem
- cua-mode Problems
- kill-buffer Induces Buffer Accumulation
- Emacs Form Feed ^L
- Inconsistency of Search Features
- Single Key to Delete Whole Line
- Emacs HTML Mode Sucks
- Emacs Does Not Support Viewing Images Files In Windows
- Emacs Spell Checker Problems
- Adopt HTML as Texinfo Replacement
- Support HTML Mail
- Problems of “man” Command
- Emacs Lisp Mode Syntax Coloring Problem
- Emacs Ahk Mode Problems
- Problems of Emacs's Manual
- Problems of Emacs's Manual; Examples
- Emacs: Have You Read Emacs Manual?
- Elisp: Ban Syntax Table
- Emacs: Make elisp-index-search use Current Symbol
- Emacs: Usability Problems of Mode Documentation
- Emacs GNU Texinfo Problems; Invalid HTML
- A Record of Frustration in IT Industry; Disappearing FSF URLs, 2006
- Emacs Manual Node Persistency Issues
- Emacs: dired-do-query-replace-regex Replace ALL (fixed)
- Problems of Emacs Supporting Obsolete Systems
- Elisp: Function to Copy/Delete a Dir Recursively (fixed)
- Thoughts on Common Lisp Scheme Lisp Based Emacs
- Text Editors Popularity and Market Research
- Text Editor's Cursor Movement Behavior (emacs, vi, Notepad++)
- GNU Emacs Development Inefficiency
- Emacs Dev Inefficiency and Emacs Web 2.0?
- Letter-Case Commands Usability Problems
- Emacs: Select Line, between Quotes, Extend Selection
- Emacs: isearch Current Word
- Suggestions on Line Wrap Commands
- Emacs: Single Key to Delete Whole Line
- Emacs Undo and Emacs Cult Problem