coolj.el (4922B)
1 ;;; coolj.el --- automatically wrap long lines -*- lexical-binding: t; coding: utf-8 -*- 2 3 ;; Copyright (C) 2000, 2001, 2004-2009 Free Software Foundation, Inc. 4 5 ;; Authors: Kai Grossjohann <Kai.Grossjohann@CS.Uni-Dortmund.DE> 6 ;; Alex Schroeder <alex@gnu.org> 7 ;; Chong Yidong <cyd@stupidchicken.com> 8 ;; Maintainer: David Edmondson <dme@dme.org> 9 ;; Keywords: convenience, wp 10 11 ;; This file is not part of GNU Emacs. 12 13 ;; GNU Emacs is free software: you can redistribute it and/or modify 14 ;; it under the terms of the GNU General Public License as published by 15 ;; the Free Software Foundation, either version 3 of the License, or 16 ;; (at your option) any later version. 17 18 ;; GNU Emacs is distributed in the hope that it will be useful, 19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of 20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 ;; GNU General Public License for more details. 22 23 ;; You should have received a copy of the GNU General Public License 24 ;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. 25 26 ;;; Commentary: 27 28 ;; This is a simple derivative of some functionality from 29 ;; `longlines.el'. The key difference is that this version will 30 ;; insert a prefix at the head of each wrapped line. The prefix is 31 ;; calculated from the originating long line. 32 33 ;; No minor-mode is provided, the caller is expected to call 34 ;; `coolj-wrap-region' to wrap the region of interest. 35 36 ;;; Code: 37 38 (defgroup coolj nil 39 "Wrapping of long lines with prefix." 40 :group 'fill) 41 42 (defcustom coolj-wrap-follows-window-size t 43 "Non-nil means wrap text to the window size. 44 Otherwise respect `fill-column'." 45 :group 'coolj 46 :type 'boolean) 47 48 (defcustom coolj-line-prefix-regexp "^\\(>+ ?\\)*" 49 "Regular expression that matches line prefixes." 50 :group 'coolj 51 :type 'regexp) 52 53 (defvar-local coolj-wrap-point nil) 54 55 (defun coolj-determine-prefix () 56 "Determine the prefix for the current line." 57 (save-excursion 58 (beginning-of-line) 59 (if (re-search-forward coolj-line-prefix-regexp nil t) 60 (buffer-substring (match-beginning 0) (match-end 0)) 61 ""))) 62 63 (defun coolj-wrap-buffer () 64 "Wrap the current buffer." 65 (coolj-wrap-region (point-min) (point-max))) 66 67 (defun coolj-wrap-region (beg end) 68 "Wrap each successive line, starting with the line before BEG. 69 Stop when we reach lines after END that don't need wrapping, or the 70 end of the buffer." 71 (setq fill-column (if coolj-wrap-follows-window-size 72 (window-width) 73 fill-column)) 74 (let ((mod (buffer-modified-p))) 75 (setq coolj-wrap-point (point)) 76 (goto-char beg) 77 (forward-line -1) 78 ;; Two successful coolj-wrap-line's in a row mean successive 79 ;; lines don't need wrapping. 80 (while (null (and (coolj-wrap-line) 81 (or (eobp) 82 (and (>= (point) end) 83 (coolj-wrap-line)))))) 84 (goto-char coolj-wrap-point) 85 (set-buffer-modified-p mod))) 86 87 (defun coolj-wrap-line () 88 "If the current line needs to be wrapped, wrap it and return nil. 89 If wrapping is performed, point remains on the line. If the line does 90 not need to be wrapped, move point to the next line and return t." 91 (let ((prefix (coolj-determine-prefix))) 92 (if (coolj-set-breakpoint prefix) 93 (progn 94 (insert-before-markers ?\n) 95 (backward-char 1) 96 (delete-char -1) 97 (forward-char 1) 98 (insert-before-markers prefix) 99 nil) 100 (forward-line 1) 101 t))) 102 103 (defun coolj-set-breakpoint (prefix) 104 "Place point where we should break the current line, and return t. 105 If the line should not be broken, return nil; point remains on the 106 line." 107 (move-to-column fill-column) 108 (and (re-search-forward "[^ ]" (line-end-position) 1) 109 (> (current-column) fill-column) 110 ;; This line is too long. Can we break it? 111 (or (coolj-find-break-backward prefix) 112 (progn (move-to-column fill-column) 113 (coolj-find-break-forward))))) 114 115 (defun coolj-find-break-backward (prefix) 116 "Move point backward to the first available breakpoint and return t. 117 If no breakpoint is found, return nil." 118 (let ((end-of-prefix (+ (line-beginning-position) (length prefix)))) 119 (and (search-backward " " end-of-prefix 1) 120 (save-excursion 121 (skip-chars-backward " " end-of-prefix) 122 (null (bolp))) 123 (progn (forward-char 1) 124 (if (and fill-nobreak-predicate 125 (run-hook-with-args-until-success 126 'fill-nobreak-predicate)) 127 (progn (skip-chars-backward " " end-of-prefix) 128 (coolj-find-break-backward prefix)) 129 t))))) 130 131 (defun coolj-find-break-forward () 132 "Move point forward to the first available breakpoint and return t. 133 If no break point is found, return nil." 134 (and (search-forward " " (line-end-position) 1) 135 (progn (skip-chars-forward " " (line-end-position)) 136 (null (eolp))) 137 (if (and fill-nobreak-predicate 138 (run-hook-with-args-until-success 139 'fill-nobreak-predicate)) 140 (coolj-find-break-forward) 141 t))) 142 143 (provide 'coolj) 144 145 ;;; coolj.el ends here