--- /dev/null
-(defcustom longlines-breakpoint-chars " ;,|"
+ ;;; longlines.el --- automatically wrap long lines -*- lexical-binding: t; -*-
+
+ ;; Copyright (C) 2000-2001, 2004-2022 Free Software Foundation, Inc.
+
+ ;; Authors: Kai Grossjohann <Kai.Grossjohann@CS.Uni-Dortmund.DE>
+ ;; Alex Schroeder <alex@gnu.org>
+ ;; Chong Yidong <cyd@stupidchicken.com>
+ ;; Maintainer: emacs-devel@gnu.org
+ ;; Obsolete-since: 24.4
+ ;; Keywords: convenience, wp
+
+ ;; This file is part of GNU Emacs.
+
+ ;; GNU Emacs 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.
+
+ ;; GNU Emacs 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 GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
+
+ ;;; Commentary:
+
+ ;; Some text editors save text files with long lines, and they
+ ;; automatically break these lines at whitespace, without actually
+ ;; inserting any newline characters. When doing `M-q' in Emacs, you
+ ;; are inserting newline characters. Longlines mode provides a file
+ ;; format which wraps the long lines when reading a file and unwraps
+ ;; the lines when saving the file. It can also wrap and unwrap
+ ;; automatically as editing takes place.
+
+ ;; Special thanks to Rod Smith for many useful bug reports.
+
+ ;;; Code:
+ ;;; Options
+
+ (defgroup longlines nil
+ "Automatic wrapping of long lines when loading files."
+ :group 'fill)
+
+ (defcustom longlines-auto-wrap t
+ "Non-nil means long lines are automatically wrapped after each command.
+ Otherwise, you can perform filling using `fill-paragraph' or
+ `auto-fill-mode'. In any case, the soft newlines will be removed
+ when the file is saved to disk."
+ :type 'boolean)
+
+ (defcustom longlines-wrap-follows-window-size nil
+ "Non-nil means wrapping and filling happen at the edge of the window.
+ Otherwise, `fill-column' is used, regardless of the window size. This
+ does not work well when the buffer is displayed in multiple windows
+ with differing widths.
+
+ If the value is an integer, that specifies the distance from the
+ right edge of the window at which wrapping occurs. For any other
+ non-nil value, wrapping occurs 2 characters from the right edge."
+ :type 'boolean)
+
+ (defcustom longlines-show-hard-newlines nil
+ "Non-nil means each hard newline is marked on the screen.
+ \(The variable `longlines-show-effect' controls what they look like.)
+ You can also enable the display temporarily, using the command
+ `longlines-show-hard-newlines'."
+ :type 'boolean)
+
+ (defcustom longlines-show-effect (propertize "ΒΆ\n" 'face 'escape-glyph)
+ "A string to display when showing hard newlines.
+ This is used when `longlines-show-hard-newlines' is on."
+ :type 'string)
+
- (make-local-variable 'buffer-substring-filters)
++(defcustom longlines-break-chars " ;,|"
+ "A bag of separator chars for longlines."
++ :version "29.1"
+ :type 'string)
+
+ ;;; Internal variables
+
+ (defvar longlines-wrap-beg nil)
+ (defvar longlines-wrap-end nil)
+ (defvar longlines-wrap-point nil)
+ (defvar longlines-showing nil)
+ (defvar longlines-decoded nil)
+
+ (make-variable-buffer-local 'longlines-wrap-beg)
+ (make-variable-buffer-local 'longlines-wrap-end)
+ (make-variable-buffer-local 'longlines-wrap-point)
+ (make-variable-buffer-local 'longlines-showing)
+ (make-variable-buffer-local 'longlines-decoded)
+
+ ;;; Mode
+
+ (defvar message-indent-citation-function)
+
+ ;;;###autoload
+ (define-minor-mode longlines-mode
+ "Toggle Long Lines mode in this buffer.
+
+ When Long Lines mode is enabled, long lines are wrapped if they
+ extend beyond `fill-column'. The soft newlines used for line
+ wrapping will not show up when the text is yanked or saved to
+ disk.
+
+ If the variable `longlines-auto-wrap' is non-nil, lines are
+ automatically wrapped whenever the buffer is changed. You can
+ always call `fill-paragraph' to fill individual paragraphs.
+
+ If the variable `longlines-show-hard-newlines' is non-nil, hard
+ newlines are indicated with a symbol."
+ :lighter " ll"
+ (if longlines-mode
+ ;; Turn on longlines mode
+ (progn
+ (use-hard-newlines 1 'never)
+ (set (make-local-variable 'require-final-newline) nil)
+ (add-to-list 'buffer-file-format 'longlines)
+ (add-hook 'change-major-mode-hook #'longlines-mode-off nil t)
+ (add-hook 'before-revert-hook #'longlines-before-revert-hook nil t)
- (add-to-list 'buffer-substring-filters 'longlines-encode-string)
+ (make-local-variable 'longlines-auto-wrap)
+ (set (make-local-variable 'isearch-search-fun-function)
+ #'longlines-search-function)
+ (set (make-local-variable 'replace-search-function)
+ #'longlines-search-forward)
+ (set (make-local-variable 'replace-re-search-function)
+ #'longlines-re-search-forward)
- ;; Turning off undo is OK since (spaces + newlines) is
++ (add-function :filter-return (local 'filter-buffer-substring-function)
++ #'longlines-encode-string)
+ (when longlines-wrap-follows-window-size
+ (let ((dw (if (and (integerp longlines-wrap-follows-window-size)
+ (>= longlines-wrap-follows-window-size 0)
+ (< longlines-wrap-follows-window-size
+ (window-width)))
+ longlines-wrap-follows-window-size
+ 2)))
+ (set (make-local-variable 'fill-column)
+ (- (window-width) dw)))
+ (add-hook 'window-configuration-change-hook
+ #'longlines-window-change-function nil t))
+ (let ((buffer-undo-list t)
+ (inhibit-read-only t)
+ (inhibit-modification-hooks t)
+ (mod (buffer-modified-p))
+ buffer-file-name buffer-file-truename)
- (kill-local-variable 'buffer-substring-filters)
++ ;; Turning off undo is OK since (separators + newlines) is
+ ;; conserved, except for a corner case in
+ ;; longlines-wrap-lines that we'll never encounter from here
+ (save-restriction
+ (widen)
+ (unless longlines-decoded
+ (longlines-decode-buffer)
+ (setq longlines-decoded t))
+ (longlines-wrap-region (point-min) (point-max)))
+ (set-buffer-modified-p mod))
+ (when (and longlines-show-hard-newlines
+ (not longlines-showing))
+ (longlines-show-hard-newlines))
+
+ ;; Hacks to make longlines play nice with various modes.
+ (cond ((eq major-mode 'mail-mode)
+ (declare-function mail-indent-citation "sendmail" ())
+ (add-hook 'mail-setup-hook #'longlines-decode-buffer nil t)
+ (or mail-citation-hook
+ (add-hook 'mail-citation-hook #'mail-indent-citation nil t))
+ (add-hook 'mail-citation-hook #'longlines-decode-region nil t))
+ ((eq major-mode 'message-mode)
+ (add-hook 'message-setup-hook #'longlines-decode-buffer nil t)
+ (make-local-variable 'message-indent-citation-function)
+ (if (not (listp message-indent-citation-function))
+ (setq message-indent-citation-function
+ (list message-indent-citation-function)))
+ (add-hook 'message-indent-citation-function
+ #'longlines-decode-region t t)))
+
+ (add-hook 'after-change-functions #'longlines-after-change-function nil t)
+ (add-hook 'post-command-hook #'longlines-post-command-function nil t)
+ (when longlines-auto-wrap
+ (auto-fill-mode 0)))
+ ;; Turn off longlines mode
+ (setq buffer-file-format (delete 'longlines buffer-file-format))
+ (if longlines-showing
+ (longlines-unshow-hard-newlines))
+ (let ((buffer-undo-list t)
+ (inhibit-modification-hooks t)
+ (inhibit-read-only t)
+ buffer-file-name buffer-file-truename)
+ (if longlines-decoded
+ (save-restriction
+ (widen)
+ (longlines-encode-region (point-min) (point-max))
+ (setq longlines-decoded nil))))
+ (remove-hook 'change-major-mode-hook #'longlines-mode-off t)
+ (remove-hook 'after-change-functions #'longlines-after-change-function t)
+ (remove-hook 'post-command-hook #'longlines-post-command-function t)
+ (remove-hook 'before-revert-hook #'longlines-before-revert-hook t)
+ (remove-hook 'window-configuration-change-hook
+ #'longlines-window-change-function t)
+ (when longlines-wrap-follows-window-size
+ (kill-local-variable 'fill-column))
+ (kill-local-variable 'isearch-search-fun-function)
+ (kill-local-variable 'replace-search-function)
+ (kill-local-variable 'replace-re-search-function)
+ (kill-local-variable 'require-final-newline)
- (let ((non-breakpoint-re (format "[^%s]" longlines-breakpoint-chars)))
- (if (and (re-search-forward non-breakpoint-re (line-end-position) t 1)
++ (remove-function (local 'filter-buffer-substring-function)
++ #'longlines-encode-string)
+ (kill-local-variable 'use-hard-newlines)))
+
+ (defun longlines-mode-off ()
+ "Turn off longlines mode.
+ This function exists to be called by `change-major-mode-hook' when the
+ major mode changes."
+ (longlines-mode 0))
+
+ ;;; Showing the effect of hard newlines in the buffer
+
+ (defun longlines-show-hard-newlines (&optional arg)
+ "Make hard newlines visible by adding a face.
+ With optional argument ARG, make the hard newlines invisible again."
+ (interactive "P")
+ (if arg
+ (longlines-unshow-hard-newlines)
+ (setq longlines-showing t)
+ (longlines-show-region (point-min) (point-max))))
+
+ (defun longlines-show-region (beg end)
+ "Make hard newlines between BEG and END visible."
+ (let* ((pmin (min beg end))
+ (pmax (max beg end))
+ (pos (text-property-not-all pmin pmax 'hard nil))
+ (mod (buffer-modified-p))
+ (buffer-undo-list t)
+ (inhibit-read-only t)
+ (inhibit-modification-hooks t)
+ buffer-file-name buffer-file-truename)
+ (while pos
+ (put-text-property pos (1+ pos) 'display
+ (copy-sequence longlines-show-effect))
+ (setq pos (text-property-not-all (1+ pos) pmax 'hard nil)))
+ (restore-buffer-modified-p mod)))
+
+ (defun longlines-unshow-hard-newlines ()
+ "Make hard newlines invisible again."
+ (interactive)
+ (setq longlines-showing nil)
+ (let ((pos (text-property-not-all (point-min) (point-max) 'hard nil))
+ (mod (buffer-modified-p))
+ (buffer-undo-list t)
+ (inhibit-read-only t)
+ (inhibit-modification-hooks t)
+ buffer-file-name buffer-file-truename)
+ (while pos
+ (remove-text-properties pos (1+ pos) '(display nil))
+ (setq pos (text-property-not-all (1+ pos) (point-max) 'hard nil)))
+ (restore-buffer-modified-p mod)))
+
+ ;;; Wrapping the paragraphs
+
+ (defun longlines-wrap-region (beg end)
+ "Wrap each successive line, starting with the line before BEG.
+ Stop when we reach lines after END that don't need wrapping, or the
+ end of the buffer."
+ (let ((mod (buffer-modified-p)))
+ (setq longlines-wrap-point (point))
+ (goto-char beg)
+ (forward-line -1)
+ ;; Two successful longlines-wrap-line's in a row mean successive
+ ;; lines don't need wrapping.
+ (while (null (and (longlines-wrap-line)
+ (or (eobp)
+ (and (>= (point) end)
+ (longlines-wrap-line))))))
+ (goto-char longlines-wrap-point)
+ (set-buffer-modified-p mod)))
+
+ (defun longlines-wrap-line ()
+ "If the current line needs to be wrapped, wrap it and return nil.
+ If wrapping is performed, point remains on the line. If the line does
+ not need to be wrapped, move point to the next line and return t."
+ (if (longlines-set-breakpoint fill-column)
+ (progn (insert-before-markers-and-inherit ?\n)
+ nil)
+ (if (longlines-merge-lines-p)
+ (progn (end-of-line)
+ ;; After certain commands (e.g. kill-line), there may be two
+ ;; successive soft newlines in the buffer. In this case, we
+ ;; replace these two newlines by a single space. Unfortunately,
+ ;; this breaks the conservation of (spaces + newlines), so we
+ ;; have to fiddle with longlines-wrap-point.
+ (if (or (prog1 (bolp) (forward-char 1)) (eolp))
+ (progn
+ (delete-char -1)
+ (if (> longlines-wrap-point (point))
+ (setq longlines-wrap-point
+ (1- longlines-wrap-point))))
+ (delete-char -1))
+ nil)
+ (forward-line 1)
+ t)))
+
+ (defun longlines-set-breakpoint (target-column)
+ "Place point where we should break the current line, and return t.
+ If the line should not be broken, return nil; point remains on the
+ line."
+ (move-to-column target-column)
- (let ((breakpoint-re (format "[%s]" longlines-breakpoint-chars)))
- (when (and (re-search-backward breakpoint-re (line-beginning-position) t 1)
++ (let ((non-break-re (format "[^%s]" longlines-break-chars)))
++ (if (and (re-search-forward non-break-re (line-end-position) t 1)
+ (> (current-column) target-column))
+ ;; This line is too long. Can we break it?
+ (or (longlines-find-break-backward)
+ (progn (move-to-column target-column)
+ (longlines-find-break-forward))))))
+
+ (defun longlines-find-break-backward ()
+ "Move point backward to the first available breakpoint and return t.
+ If no breakpoint is found, return nil."
- (skip-chars-backward longlines-breakpoint-chars
++ (let ((break-re (format "[%s]" longlines-break-chars)))
++ (when (and (re-search-backward break-re (line-beginning-position) t 1)
+ (save-excursion
- (skip-chars-backward longlines-breakpoint-chars
++ (skip-chars-backward longlines-break-chars
+ (line-beginning-position))
+ (null (bolp))))
+ (forward-char 1)
+ (if (and fill-nobreak-predicate
+ (run-hook-with-args-until-success 'fill-nobreak-predicate))
+ (progn
- (let ((breakpoint-re (format "[%s]" longlines-breakpoint-chars)))
- (and (re-search-forward breakpoint-re (line-end-position) t 1)
++ (skip-chars-backward longlines-break-chars
+ (line-beginning-position))
+ (longlines-find-break-backward))
+ t))))
+
+ (defun longlines-find-break-forward ()
+ "Move point forward to the first available breakpoint and return t.
+ If no break point is found, return nil."
- (skip-chars-forward longlines-breakpoint-chars (line-end-position))
++ (let ((break-re (format "[%s]" longlines-break-chars)))
++ (and (re-search-forward break-re (line-end-position) t 1)
+ (progn
- "Return a copy of STRING with each soft newline replaced by a space.
++ (skip-chars-forward longlines-break-chars (line-end-position))
+ (null (eolp)))
+ (if (and fill-nobreak-predicate
+ (run-hook-with-args-until-success 'fill-nobreak-predicate))
+ (longlines-find-break-forward)
+ t))))
+
+ (defun longlines-merge-lines-p ()
+ "Return t if part of the next line can fit onto the current line.
+ Otherwise, return nil. Text cannot be moved across hard newlines."
+ (save-excursion
+ (end-of-line)
+ (and (null (eobp))
+ (null (get-text-property (point) 'hard))
+ (let ((space (- fill-column (current-column))))
+ (forward-line 1)
+ (longlines-set-breakpoint (max 0 (1- space)))))))
+
+ (defun longlines-decode-region (&optional beg end)
+ "Turn all newlines between BEG and END into hard newlines.
+ If BEG and END are nil, the point and mark are used."
+ (if (null beg) (setq beg (point)))
+ (if (null end) (setq end (mark t)))
+ (save-excursion
+ (let ((reg-max (max beg end)))
+ (goto-char (min beg end))
+ (while (search-forward "\n" reg-max t)
+ (set-hard-newline-properties
+ (match-beginning 0) (match-end 0))))))
+
+ (defun longlines-decode-buffer ()
+ "Turn all newlines in the buffer into hard newlines."
+ (longlines-decode-region (point-min) (point-max)))
+
+ (defun longlines-encode-region (beg end &optional _buffer)
+ "Remove each soft newline between BEG and END.
+ Hard newlines are left intact. The optional argument BUFFER exists for
+ compatibility with `format-alist', and is ignored."
+ (save-excursion
+ (let ((reg-max (max beg end))
+ (mod (buffer-modified-p)))
+ (goto-char (min beg end))
+ (while (search-forward "\n" reg-max t)
+ (let ((pos (match-beginning 0)))
+ (unless (get-text-property pos 'hard)
+ (remove-text-properties pos (1+ pos) '(hard nil))
+ (delete-region pos (1+ pos)))))
+ (set-buffer-modified-p mod)
+ end)))
+
+ (defun longlines-encode-string (string)
- (let* ((str (copy-sequence string))
- (pos (string-search "\n" str)))
- (while pos
- (if (null (get-text-property pos 'hard str))
- (aset str pos ? ))
- (setq pos (string-search "\n" str (1+ pos))))
- str))
++ "Return a copy of STRING with each soft newline removed.
+ Hard newlines are left intact."
++ (let ((start 0)
++ (result nil)
++ pos)
++ (while (setq pos (string-search "\n" string start))
++ (unless (= start pos)
++ (push (substring string start pos) result))
++ (when (get-text-property pos 'hard string)
++ (push (substring string pos (1+ pos)) result))
++ (setq start (1+ pos)))
++ (if (null result)
++ (copy-sequence string)
++ (unless (= start (length string))
++ (push (substring string start) result))
++ (apply #'concat (nreverse result)))))
+
+ ;;; Auto wrap
+
+ (defun longlines-auto-wrap (&optional arg)
+ "Toggle automatic line wrapping.
+ With optional argument ARG, turn on line wrapping if and only if
+ ARG is positive.
+ If automatic line wrapping is turned on, wrap the entire buffer."
+ (interactive "P")
+ (setq arg (if arg
+ (> (prefix-numeric-value arg) 0)
+ (not longlines-auto-wrap)))
+ (if arg
+ (progn
+ (setq longlines-auto-wrap t)
+ (longlines-wrap-region (point-min) (point-max))
+ (message "Auto wrap enabled."))
+ (setq longlines-auto-wrap nil)
+ (message "Auto wrap disabled.")))
+
+ (defun longlines-after-change-function (beg end _len)
+ "Update `longlines-wrap-beg' and `longlines-wrap-end'.
+ This is called by `after-change-functions' to keep track of the region
+ that has changed."
+ (when (and longlines-auto-wrap (not undo-in-progress))
+ (setq longlines-wrap-beg
+ (if longlines-wrap-beg (min longlines-wrap-beg beg) beg))
+ (setq longlines-wrap-end
+ (if longlines-wrap-end (max longlines-wrap-end end) end))))
+
+ (defun longlines-post-command-function ()
+ "Perform line wrapping on the parts of the buffer that have changed.
+ This is called by `post-command-hook' after each command."
+ (when (and longlines-auto-wrap longlines-wrap-beg)
+ (if (or (eq this-command 'yank)
+ (eq this-command 'yank-pop))
+ (longlines-decode-region (point) (mark t)))
+ (if longlines-showing
+ (longlines-show-region longlines-wrap-beg longlines-wrap-end))
+ (unless (or (eq this-command 'fill-paragraph)
+ (eq this-command 'fill-region))
+ (longlines-wrap-region longlines-wrap-beg longlines-wrap-end))
+ (setq longlines-wrap-beg nil)
+ (setq longlines-wrap-end nil)))
+
+ (defun longlines-window-change-function ()
+ "Re-wrap the buffer if the window width has changed.
+ This is called by `window-configuration-change-hook'."
+ (let ((dw (if (and (integerp longlines-wrap-follows-window-size)
+ (>= longlines-wrap-follows-window-size 0)
+ (< longlines-wrap-follows-window-size (window-width)))
+ longlines-wrap-follows-window-size
+ 2)))
+ (when (/= fill-column (- (window-width) dw))
+ (setq fill-column (- (window-width) dw))
+ (longlines-wrap-region (point-min) (point-max)))))
+
+ ;;; Isearch
+
+ (defun longlines-search-function ()
+ (cond
+ ((or isearch-regexp-function isearch-regexp) (isearch-search-fun-default))
+ (isearch-forward #'longlines-search-forward)
+ (t #'longlines-search-backward)))
+
+ (defun longlines-search-forward (string &optional bound noerror count)
+ (let ((search-spaces-regexp " *[ \n]"))
+ (re-search-forward (regexp-quote string) bound noerror count)))
+
+ (defun longlines-search-backward (string &optional bound noerror count)
+ (let ((search-spaces-regexp " *[ \n]"))
+ (re-search-backward (regexp-quote string) bound noerror count)))
+
+ (defun longlines-re-search-forward (string &optional bound noerror count)
+ (let ((search-spaces-regexp " *[ \n]"))
+ (re-search-forward string bound noerror count)))
+
+ ;;; Loading and saving
+
+ (defun longlines-before-revert-hook ()
+ (add-hook 'after-revert-hook #'longlines-after-revert-hook nil t)
+ (longlines-mode 0))
+
+ (defun longlines-after-revert-hook ()
+ (remove-hook 'after-revert-hook #'longlines-after-revert-hook t)
+ (longlines-mode 1))
+
+ (add-to-list
+ 'format-alist
+ (list 'longlines "Automatically wrap long lines." nil nil
+ #'longlines-encode-region t nil))
+
+ ;;; Unloading
+
+ (defun longlines-unload-function ()
+ "Unload the longlines library."
+ (save-current-buffer
+ (dolist (buffer (buffer-list))
+ (set-buffer buffer)
+ (longlines-mode-off)))
+ ;; continue standard unloading
+ nil)
+
+ (provide 'longlines)
+
+ ;;; longlines.el ends here
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