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+;;; custom-case.el --- Custom Functions Handling Text Case -*- coding: utf-8; lexical-binding: t; -*-
+
+;;; Commentary:
+;;
+
+;;; Code:
+
+(defun cj/upcase-dwim ()
+  "Upcase the active region, or upcase the symbol at point if no region."
+  (interactive)
+  (if (use-region-p)
+	  (upcase-region (region-beginning) (region-end))
+	(let ((bounds (bounds-of-thing-at-point 'symbol)))
+	  (if bounds
+		  (upcase-region (car bounds) (cdr bounds))
+		(user-error "No symbol at point")))))
+
+(defun cj/downcase-dwim ()
+  "Downcase the active region, or downcase the symbol at point if no region."
+  (interactive)
+  (if (use-region-p)
+	  (downcase-region (region-beginning) (region-end))
+	(let ((bounds (bounds-of-thing-at-point 'symbol)))
+	  (if bounds
+		  (downcase-region (car bounds) (cdr bounds))
+		(user-error "No symbol at point")))))
+
+(defun cj/title-case-region ()
+  "Capitalize the region in title case format.
+Title case is a capitalization convention where major words
+are capitalized,and most minor words are lowercase.  Nouns,
+verbs (including linking verbs), adjectives, adverbs,pronouns,
+and all words of four letters or more are considered major words.
+Short (i.e., three letters or fewer) conjunctions, short prepositions,
+and all articles are considered minor words."
+  (interactive)
+  (let ((beg nil)
+		(end nil)
+		(prev-word-end nil)
+		;; Allow capitals for skip characters after this, so:
+		;;   Warning: An Example
+		;; Capitalizes the `An'.
+		(chars-skip-reset '(?: ?! ??))
+		;; Don't capitalize characters directly after these. e.g.
+		;; "Foo-bar" or "Foo\bar" or "Foo's".
+
+		(chars-separator '(?\\ ?- ?' ?.))
+
+		(word-chars "[:alnum:]")
+		(word-skip
+		 (list "a" "an" "and" "as" "at" "but" "by"
+			   "for" "if" "in" "is" "nor" "of"
+			   "on" "or" "so" "the" "to" "yet"))
+		(is-first t))
+	(cond
+	 ((region-active-p)
+	  (setq beg (region-beginning))
+	  (setq end (region-end)))
+	 (t
+	  (setq beg (line-beginning-position))
+	  (setq end (line-end-position))))
+	(save-excursion
+	  ;; work on uppercased text (e.g., headlines) by downcasing first
+	  (downcase-region beg end)
+	  (goto-char beg)
+
+	  (while (< (point) end)
+		(setq prev-word-end (point))
+		(skip-chars-forward (concat "^" word-chars) end)
+		(let ((word-end
+			   (save-excursion
+				 (skip-chars-forward word-chars end)
+				 (point))))
+
+		  (unless (memq (char-before (point)) chars-separator)
+			(let* ((c-orig (char-to-string (char-after (point))))
+				   (c-up (capitalize c-orig)))
+			  (unless (string-equal c-orig c-up)
+				(let ((word (buffer-substring-no-properties (point) word-end)))
+				  (when
+					  (or
+					   ;; Always allow capitalization.
+					   is-first
+					   ;; If it's not a skip word, allow.
+					   (not (member word word-skip))
+					   ;; Check the beginning of the previous word doesn't reset first.
+					   (save-excursion
+						 (and
+						  (not (zerop
+								(skip-chars-backward "[:blank:]" prev-word-end)))
+						  (memq (char-before (point)) chars-skip-reset))))
+					(delete-region (point) (1+ (point)))
+					(insert c-up))))))
+		  (goto-char word-end)
+		  (setq is-first nil))))))
+;; replace the capitalize-region keybinding to call title-case
+(global-set-key [remap capitalize-region] 'cj/title-case-region)
+
+;; Case-change operations prefix and keymap
+(define-prefix-command 'cj/case-map nil
+					   "Keymap for case-change operations.")
+(define-key cj/custom-keymap "c" 'cj/case-map)
+(define-key cj/case-map "t" 'cj/title-case-region)
+(define-key cj/case-map "u" 'cj/upcase-dwim)
+(define-key cj/case-map "l" 'cj/downcase-dwim) ;; for "lower" case
+
+(provide 'custom-case)
+;;; custom-case.el ends here.