commit b8214a03123e52e9b8abc24f927cef71e5f984ec
Author: Tom Willemse <tom@ryuslash.org>
Date:   Wed Jan 1 21:12:07 2014 +0100

    Initial commit

diff --git a/upcase-mode.el b/upcase-mode.el
new file mode 100644
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--- /dev/null
+++ b/upcase-mode.el
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+;;; upcase-mode.el --- Upcase all input              -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2014  Tom Willemse
+
+;; Author: Tom Willemse <tom@ryuslash.org>
+;; Keywords: convenience
+;; Version: 0.1.0
+
+;; This program 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 program 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 program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; The main entry point for this module, `upcase-transient-mode',
+;; temporarily enables a keymap that causes all input to be made
+;; upper-case.  This map stays active as long as the result of
+;; `upcase' applied to the input is different from the input itself,
+;; or if there is a value in `upcase-character-map' for the input.
+
+;;; Code:
+
+(defvar upcase-transient-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map [remap self-insert-command] #'upcase-self-insert-command)
+    map))
+
+(defvar upcase-character-map
+  #s(hash-table data (?- ?_)))
+
+(defun upcase-self-insert-command ()
+  "Wrap `self-insert-command' to upcase the input character.
+
+This also translates keys from the variable
+`upcase-character-map' to values from the same variable."
+  (interactive)
+  (let ((last-command-event
+         (gethash last-command-event upcase-character-map
+                  (upcase last-command-event))))
+    (self-insert-command 1)))
+
+(defun upcase-able-p ()
+  "Check to see if the current input can be upcased.
+
+Upcased can mean either the result of `upcase' being different
+from the original or having a value in `upcase-character-map'."
+  (let ((case-fold-search nil))
+    (or (not (char-equal
+              last-command-event (capitalize last-command-event)))
+        (gethash last-command-event upcase-character-map))))
+
+;;;###autoload
+(defun upcase-transient-mode ()
+  "Set a transient map that upcases any input.
+
+This map stays active as long as the input can be upcased."
+  (interactive)
+  (set-transient-map upcase-transient-map #'upcase-able-p))
+
+(provide 'upcase-mode)
+;;; upcase-mode.el ends here