diff options
| -rw-r--r-- | modules/custom-case.el | 112 |
1 files changed, 64 insertions, 48 deletions
diff --git a/modules/custom-case.el b/modules/custom-case.el index dde2d6c1..c203cd9e 100644 --- a/modules/custom-case.el +++ b/modules/custom-case.el @@ -62,6 +62,61 @@ CHARS-SKIP-RESET: : ! ? .), reached by skipping blanks back to PREV-WORD-END." (and (not (zerop (skip-chars-backward "[:blank:]" prev-word-end))) (memq (char-before (point)) chars-skip-reset))))) +(defconst cj/--title-case-reset-chars '(?: ?! ?? ?.) + "Characters that restart capitalization for the following word. +So \"Warning: An Example\" capitalizes the \"An\" and a sentence-ending +period capitalizes the next word (\"End. The Next\").") + +(defconst cj/--title-case-separator-chars '(?\\ ?- ?' ?.) + "Characters whose following character is never capitalized. +Covers \"Foo-bar\", \"Foo\\bar\", and \"Foo's\". The period keeps +\"3.14\" and \"foo.bar\" untouched; a period followed by a blank still +restarts capitalization via `cj/--title-case-reset-chars'.") + +(defconst cj/--title-case-minor-words + '("a" "an" "and" "as" "at" "but" "by" + "for" "if" "in" "nor" "of" + "on" "or" "so" "the" "to" "yet") + "Minor words kept lowercase mid-title. +\"is\" and other linking verbs are major words, so they are not here.") + +(defconst cj/--title-case-word-chars "[:alnum:]" + "skip-chars set that constitutes a word for title-casing.") + +(defun cj/--title-case-region-bounds () + "Return (BEG . END) for the active region, else the current line." + (if (region-active-p) + (cons (region-beginning) (region-end)) + (cons (line-beginning-position) (line-end-position)))) + +(defun cj/--title-case-last-word-start (beg end) + "Return the start position of the last word in BEG..END. +The last word is always capitalized in title case, so it is located once: +from END, skip back over trailing non-word characters, then the word." + (save-excursion + (goto-char end) + (skip-chars-backward (concat "^" cj/--title-case-word-chars) beg) + (skip-chars-backward cj/--title-case-word-chars beg) + (point))) + +(defun cj/--title-case-maybe-capitalize (word-end end is-first last-word-start prev-word-end) + "Capitalize the character at point when title-case rules call for it. +Point sits on a word's first character, WORD-END past its last. END bounds +the operation; IS-FIRST, LAST-WORD-START, and PREV-WORD-END feed +`cj/--title-case-capitalize-word-p'. Modifies the buffer in place." + (unless (or (>= (point) end) + (memq (char-before (point)) cj/--title-case-separator-chars)) + (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 (cj/--title-case-capitalize-word-p + word is-first (= (point) last-word-start) + prev-word-end cj/--title-case-minor-words + cj/--title-case-reset-chars) + (delete-region (point) (1+ (point))) + (insert c-up))))))) + (defun cj/title-case-region () "Capitalize the region in title case format. Title case is a capitalization convention where major words are capitalized, @@ -73,43 +128,13 @@ and last words are always capitalized, and a word following a sentence-ending period (or a colon, exclamation mark, or question mark) restarts capitalization even when it is a minor word." (interactive) - (let ((beg nil) - (end nil) - (prev-word-end nil) - (last-word-start nil) - ;; Restart capitalization for a minor word after one of these, so - ;; "Warning: An Example" capitalizes the "An" and a sentence-ending - ;; period capitalizes the next word ("End. The Next"). - (chars-skip-reset '(?: ?! ?? ?.)) - ;; Don't capitalize characters directly after these. e.g. - ;; "Foo-bar" or "Foo\bar" or "Foo's". A period is here too, so - ;; "3.14" and "foo.bar" are left alone; a period followed by a - ;; blank still restarts via `chars-skip-reset' above. - (chars-separator '(?\\ ?- ?' ?.)) - (word-chars "[:alnum:]") - ;; "is" and other linking verbs are major words, so they are not in - ;; this minor-word skip list. - (word-skip - (list "a" "an" "and" "as" "at" "but" "by" - "for" "if" "in" "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)))) - ;; The last word is always capitalized in title case, so find its start - ;; once: from END, skip back over any trailing non-word chars, then over - ;; the word itself. - (setq last-word-start - (save-excursion - (goto-char end) - (skip-chars-backward (concat "^" word-chars) beg) - (skip-chars-backward word-chars beg) - (point))) + (let* ((bounds (cj/--title-case-region-bounds)) + (beg (car bounds)) + (end (cdr bounds)) + (last-word-start (cj/--title-case-last-word-start beg end)) + (word-chars cj/--title-case-word-chars) + (prev-word-end nil) + (is-first t)) (save-excursion ;; work on uppercased text (e.g., headlines) by downcasing first (downcase-region beg end) @@ -123,17 +148,8 @@ capitalization even when it is a minor word." (save-excursion (skip-chars-forward word-chars end) (point)))) - (unless (or (>= (point) end) - (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 (cj/--title-case-capitalize-word-p - word is-first (= (point) last-word-start) - prev-word-end word-skip chars-skip-reset) - (delete-region (point) (1+ (point))) - (insert c-up)))))) + (cj/--title-case-maybe-capitalize + word-end end is-first last-word-start prev-word-end) (goto-char word-end) (setq is-first nil)))))) |