lisp/textmodes/nroff-mode.el

   1 ;;; nroff-mode.el --- GNU Emacs major mode for editing nroff source
   2
   3 ;; Copyright (C) 1985, 1986 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: wp
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Code:
  25
  26 (defvar nroff-mode-abbrev-table nil
  27   "Abbrev table used while in nroff mode.")
  28
  29 (defvar nroff-mode-map nil
  30      "Major mode keymap for nroff mode.")
  31 (if (not nroff-mode-map)
  32     (progn
  33       (setq nroff-mode-map (make-sparse-keymap))
  34       (define-key nroff-mode-map "\t"  'tab-to-tab-stop)
  35       (define-key nroff-mode-map "\es" 'center-line)
  36       (define-key nroff-mode-map "\e?" 'count-text-lines)
  37       (define-key nroff-mode-map "\n"  'electric-nroff-newline)
  38       (define-key nroff-mode-map "\en" 'forward-text-line)
  39       (define-key nroff-mode-map "\ep" 'backward-text-line)))
  40
  41 ;;;###autoload
  42 (defun nroff-mode ()
  43   "Major mode for editing text intended for nroff to format.
  44 \\{nroff-mode-map}
  45 Turning on Nroff mode runs `text-mode-hook', then `nroff-mode-hook'.
  46 Also, try `nroff-electric-mode', for automatically inserting
  47 closing requests for requests that are used in matched pairs."
  48   (interactive)
  49   (kill-all-local-variables)
  50   (use-local-map nroff-mode-map)
  51   (setq mode-name "Nroff")
  52   (setq major-mode 'nroff-mode)
  53   (set-syntax-table text-mode-syntax-table)
  54   (setq local-abbrev-table nroff-mode-abbrev-table)
  55   (make-local-variable 'nroff-electric-mode)
  56   ;; now define a bunch of variables for use by commands in this mode
  57   (make-local-variable 'page-delimiter)
  58   (setq page-delimiter "^\\.\\(bp\\|SK\\|OP\\)")
  59   (make-local-variable 'paragraph-start)
  60   (setq paragraph-start (concat "^[.']\\|" paragraph-start))
  61   (make-local-variable 'paragraph-separate)
  62   (setq paragraph-separate (concat "^[.']\\|" paragraph-separate))
  63   ;; comment syntax added by mit-erl!gildea 18 Apr 86
  64   (make-local-variable 'comment-start)
  65   (setq comment-start "\\\" ")
  66   (make-local-variable 'comment-start-skip)
  67   (setq comment-start-skip "\\\\\"[ \t]*")
  68   (make-local-variable 'comment-column)
  69   (setq comment-column 24)
  70   (make-local-variable 'comment-indent-hook)
  71   (setq comment-indent-hook 'nroff-comment-indent)
  72   (run-hooks 'text-mode-hook 'nroff-mode-hook))
  73
  74 ;;; Compute how much to indent a comment in nroff/troff source.
  75 ;;; By mit-erl!gildea April 86
  76 (defun nroff-comment-indent ()
  77   "Compute indent for an nroff/troff comment.
  78 Puts a full-stop before comments on a line by themselves."
  79   (let ((pt (point)))
  80     (unwind-protect
  81         (progn
  82           (skip-chars-backward " \t")
  83           (if (bolp)
  84               (progn
  85                 (setq pt (1+ pt))
  86                 (insert ?.)
  87                 1)
  88             (if (save-excursion
  89                   (backward-char 1)
  90                   (looking-at "^[.']"))
  91                 1
  92               (max comment-column
  93                    (* 8 (/ (+ (current-column)
  94                               9) 8)))))) ; add 9 to ensure at least two blanks
  95       (goto-char pt))))
  96
  97 (defun count-text-lines (start end &optional print)
  98   "Count lines in region, except for nroff request lines.
  99 All lines not starting with a period are counted up.
 100 Interactively, print result in echo area.
 101 Noninteractively, return number of non-request lines from START to END."
 102   (interactive "r\np")
 103   (if print
 104       (message "Region has %d text lines" (count-text-lines start end))
 105     (save-excursion
 106       (save-restriction
 107         (narrow-to-region start end)
 108         (goto-char (point-min))
 109         (- (buffer-size) (forward-text-line (buffer-size)))))))
 110
 111 (defun forward-text-line (&optional cnt)
 112   "Go forward one nroff text line, skipping lines of nroff requests.
 113 An argument is a repeat count; if negative, move backward."
 114   (interactive "p")
 115   (if (not cnt) (setq cnt 1))
 116   (while (and (> cnt 0) (not (eobp)))
 117     (forward-line 1)
 118     (while (and (not (eobp)) (looking-at "[.']."))
 119       (forward-line 1))
 120     (setq cnt (- cnt 1)))
 121   (while (and (< cnt 0) (not (bobp)))
 122     (forward-line -1)
 123     (while (and (not (bobp))
 124                 (looking-at "[.']."))
 125       (forward-line -1))
 126     (setq cnt (+ cnt 1)))
 127   cnt)
 128
 129 (defun backward-text-line (&optional cnt)
 130   "Go backward one nroff text line, skipping lines of nroff requests.
 131 An argument is a repeat count; negative means move forward."
 132   (interactive "p")
 133   (forward-text-line (- cnt)))
 134
 135 (defconst nroff-brace-table
 136   '((".(b" . ".)b")
 137     (".(l" . ".)l")
 138     (".(q" . ".)q")
 139     (".(c" . ".)c")
 140     (".(x" . ".)x")
 141     (".(z" . ".)z")
 142     (".(d" . ".)d")
 143     (".(f" . ".)f")
 144     (".LG" . ".NL")
 145     (".SM" . ".NL")
 146     (".LD" . ".DE")
 147     (".CD" . ".DE")
 148     (".BD" . ".DE")
 149     (".DS" . ".DE")
 150     (".DF" . ".DE")
 151     (".FS" . ".FE")
 152     (".KS" . ".KE")
 153     (".KF" . ".KE")
 154     (".LB" . ".LE")
 155     (".AL" . ".LE")
 156     (".BL" . ".LE")
 157     (".DL" . ".LE")
 158     (".ML" . ".LE")
 159     (".RL" . ".LE")
 160     (".VL" . ".LE")
 161     (".RS" . ".RE")
 162     (".TS" . ".TE")
 163     (".EQ" . ".EN")
 164     (".PS" . ".PE")
 165     (".BS" . ".BE")
 166     (".G1" . ".G2")                     ; grap
 167     (".na" . ".ad b")
 168     (".nf" . ".fi")
 169     (".de" . "..")))
 170
 171 (defun electric-nroff-newline (arg)
 172   "Insert newline for nroff mode; special if electric-nroff mode.
 173 In `electric-nroff-mode', if ending a line containing an nroff opening request,
 174 automatically inserts the matching closing request after point."
 175   (interactive "P")
 176   (let ((completion (save-excursion
 177                       (beginning-of-line)
 178                       (and (null arg)
 179                            nroff-electric-mode
 180                            (<= (point) (- (point-max) 3))
 181                            (cdr (assoc (buffer-substring (point)
 182                                                          (+ 3 (point)))
 183                                        nroff-brace-table)))))
 184         (needs-nl (not (looking-at "[ \t]*$"))))
 185     (if (null completion)
 186         (newline (prefix-numeric-value arg))
 187       (save-excursion
 188         (insert "\n\n" completion)
 189         (if needs-nl (insert "\n")))
 190       (forward-char 1))))
 191
 192 (defun electric-nroff-mode (&optional arg)
 193   "Toggle `nroff-electric-newline' minor mode.
 194 `nroff-electric-newline' forces Emacs to check for an nroff request at the
 195 beginning of the line, and insert the matching closing request if necessary.
 196 This command toggles that mode (off->on, on->off), with an argument,
 197 turns it on iff arg is positive, otherwise off."
 198   (interactive "P")
 199   (or (eq major-mode 'nroff-mode) (error "Must be in nroff mode"))
 200   (or (assq 'nroff-electric-mode minor-mode-alist)
 201       (setq minor-mode-alist (append minor-mode-alist
 202                                      (list '(nroff-electric-mode
 203                                              " Electric")))))
 204   (setq nroff-electric-mode
 205         (cond ((null arg) (null nroff-electric-mode))
 206               (t (> (prefix-numeric-value arg) 0)))))
 207
 208 ;;; nroff-mode.el ends here