diff options
Diffstat (limited to 'modules/custom-case.el')
| -rw-r--r-- | modules/custom-case.el | 111 |
1 files changed, 73 insertions, 38 deletions
diff --git a/modules/custom-case.el b/modules/custom-case.el index 87622695..c203cd9e 100644 --- a/modules/custom-case.el +++ b/modules/custom-case.el @@ -49,49 +49,92 @@ (downcase-region (car bounds) (cdr bounds)) (user-error "No symbol at point"))))) -(defun cj/--title-case-capitalize-word-p (word is-first prev-word-end word-skip chars-skip-reset) +(defun cj/--title-case-capitalize-word-p (word is-first is-last prev-word-end word-skip chars-skip-reset) "Return non-nil when WORD at point should be capitalized in title case. Point is at WORD's first character. WORD is capitalized when it is the first -word (IS-FIRST), is not a minor skip word (in WORD-SKIP), or immediately follows -a skip-reset character (one of CHARS-SKIP-RESET: : ! ?), reached by skipping -blanks back to PREV-WORD-END." +word (IS-FIRST) or the last word (IS-LAST), is not a minor skip word (in +WORD-SKIP), or immediately follows a skip-reset character (one of +CHARS-SKIP-RESET: : ! ? .), reached by skipping blanks back to PREV-WORD-END." (or is-first + is-last (not (member word word-skip)) (save-excursion (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, 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." +short prepositions, and all articles are considered minor words. The first +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) - ;; 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)))) + (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) @@ -105,16 +148,8 @@ short prepositions, and all articles are considered minor words." (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 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)))))) |