1 ;;; nroff-mode.el --- GNU Emacs major mode for editing nroff source
3 ;; Copyright (C) 1985, 1986, 1994, 1995 Free Software Foundation, Inc.
8 ;; This file is part of GNU Emacs.
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)
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.
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 the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 ;; This package is a major mode for editing nroff source code. It knows
28 ;; about various nroff constructs, ms, mm, and me macros, and will fill
29 ;; and indent paragraphs properly in their presence. It also includes
30 ;; a command to count text lines (excluding nroff constructs), a command
31 ;; to center a line, and movement commands that know how to skip macros.
33 ;; Paragraph filling and line-counting currently don't respect comments,
43 (defcustom nroff-electric-mode nil
44 "*Non-nil means automatically closing requests when you insert an open."
48 (defvar nroff-mode-map
49 (let ((map (make-sparse-keymap)))
50 (define-key map
"\t" 'tab-to-tab-stop
)
51 (define-key map
"\es" 'center-line
)
52 (define-key map
"\e?" 'count-text-lines
)
53 (define-key map
"\n" 'electric-nroff-newline
)
54 (define-key map
"\en" 'forward-text-line
)
55 (define-key map
"\ep" 'backward-text-line
)
57 "Major mode keymap for `nroff-mode'.")
59 (defvar nroff-mode-syntax-table
60 (let ((st (copy-syntax-table text-mode-syntax-table
)))
61 ;; " isn't given string quote syntax in text-mode but it
62 ;; (arguably) should be for use round nroff arguments (with ` and
64 (modify-syntax-entry ?
\" "\" 2" st
)
65 ;; Comments are delimited by \" and newline.
66 (modify-syntax-entry ?
\\ "\\ 1" st
)
67 (modify-syntax-entry ?
\n "> 1" st
)
69 "Syntax table used while in `nroff-mode'.")
71 (defcustom nroff-font-lock-keywords
73 ;; Directives are . or ' at start of line, followed by
74 ;; optional whitespace, then command (which my be longer than
75 ;; 2 characters in groff). Perhaps the arguments should be
78 ;; There are numerous groff escapes; the following get things
79 ;; like \-, \(em (standard troff) and \f[bar] (groff
80 ;; variants). This won't currently do groff's \A'foo' and
81 ;; the like properly. One might expect it to highlight an escape's
82 ;; arguments in common cases, like \f.
83 (concat "\\\\" ; backslash
84 "\\(" ; followed by various possibilities
86 '("[f*n]*\\[.+]" ; some groff extensions
87 "(.." ; two chars after (
88 "[^(\"]" ; single char escape
92 "Font-lock highlighting control in `nroff-mode'."
94 :type
'(repeat regexp
))
97 (define-derived-mode nroff-mode text-mode
"Nroff"
98 "Major mode for editing text intended for nroff to format.
100 Turning on Nroff mode runs `text-mode-hook', then `nroff-mode-hook'.
101 Also, try `nroff-electric-mode', for automatically inserting
102 closing requests for requests that are used in matched pairs."
103 (set (make-local-variable 'font-lock-defaults
)
104 ;; SYNTAX-BEGIN is set to backward-paragraph to avoid slow-down
105 ;; near the end of large buffers due to searching to buffer's
107 '(nroff-font-lock-keywords nil t nil backward-paragraph
))
108 (set (make-local-variable 'nroff-electric-mode
) nil
)
109 (set (make-local-variable 'outline-regexp
) "\\.H[ ]+[1-7]+ ")
110 (set (make-local-variable 'outline-level
) 'nroff-outline-level
)
111 ;; now define a bunch of variables for use by commands in this mode
112 (set (make-local-variable 'page-delimiter
) "^\\.\\(bp\\|SK\\|OP\\)")
113 (set (make-local-variable 'paragraph-start
)
114 (concat "[.']\\|" paragraph-start
))
115 (set (make-local-variable 'paragraph-separate
)
116 (concat "[.']\\|" paragraph-separate
))
117 ;; comment syntax added by mit-erl!gildea 18 Apr 86
118 (set (make-local-variable 'comment-start
) "\\\" ")
119 (set (make-local-variable 'comment-start-skip
) "\\\\\"[ \t]*")
120 (set (make-local-variable 'comment-column
) 24)
121 (set (make-local-variable 'comment-indent-function
) 'nroff-comment-indent
))
123 (defun nroff-outline-level ()
125 (looking-at outline-regexp
)
126 (skip-chars-forward ".H ")
127 (string-to-int (buffer-substring (point) (+ 1 (point))))))
129 ;;; Compute how much to indent a comment in nroff/troff source.
130 ;;; By mit-erl!gildea April 86
131 (defun nroff-comment-indent ()
132 "Compute indent for an nroff/troff comment.
133 Puts a full-stop before comments on a line by themselves."
137 (skip-chars-backward " \t")
145 (looking-at "^[.']"))
148 (* 8 (/ (+ (current-column)
149 9) 8)))))) ; add 9 to ensure at least two blanks
152 (defun count-text-lines (start end
&optional print
)
153 "Count lines in region, except for nroff request lines.
154 All lines not starting with a period are counted up.
155 Interactively, print result in echo area.
156 Noninteractively, return number of non-request lines from START to END."
159 (message "Region has %d text lines" (count-text-lines start end
))
162 (narrow-to-region start end
)
163 (goto-char (point-min))
164 (- (buffer-size) (forward-text-line (buffer-size)))))))
166 (defun forward-text-line (&optional cnt
)
167 "Go forward one nroff text line, skipping lines of nroff requests.
168 An argument is a repeat count; if negative, move backward."
170 (if (not cnt
) (setq cnt
1))
171 (while (and (> cnt
0) (not (eobp)))
173 (while (and (not (eobp)) (looking-at "[.']."))
175 (setq cnt
(- cnt
1)))
176 (while (and (< cnt
0) (not (bobp)))
178 (while (and (not (bobp))
179 (looking-at "[.']."))
181 (setq cnt
(+ cnt
1)))
184 (defun backward-text-line (&optional cnt
)
185 "Go backward one nroff text line, skipping lines of nroff requests.
186 An argument is a repeat count; negative means move forward."
188 (forward-text-line (- cnt
)))
190 (defconst nroff-brace-table
221 (".G1" .
".G2") ; grap
226 (defun electric-nroff-newline (arg)
227 "Insert newline for nroff mode; special if electric-nroff mode.
228 In `electric-nroff-mode', if ending a line containing an nroff opening request,
229 automatically inserts the matching closing request after point."
231 (let ((completion (save-excursion
235 (<= (point) (- (point-max) 3))
236 (cdr (assoc (buffer-substring (point)
238 nroff-brace-table
)))))
239 (needs-nl (not (looking-at "[ \t]*$"))))
240 (if (null completion
)
241 (newline (prefix-numeric-value arg
))
243 (insert "\n\n" completion
)
244 (if needs-nl
(insert "\n")))
247 (defun electric-nroff-mode (&optional arg
)
248 "Toggle `nroff-electric-newline' minor mode.
249 `nroff-electric-newline' forces Emacs to check for an nroff request at the
250 beginning of the line, and insert the matching closing request if necessary.
251 This command toggles that mode (off->on, on->off), with an argument,
252 turns it on iff arg is positive, otherwise off."
254 (or (eq major-mode
'nroff-mode
) (error "Must be in nroff mode"))
255 (or (assq 'nroff-electric-mode minor-mode-alist
)
256 (setq minor-mode-alist
(append minor-mode-alist
257 (list '(nroff-electric-mode
259 (setq nroff-electric-mode
260 (cond ((null arg
) (null nroff-electric-mode
))
261 (t (> (prefix-numeric-value arg
) 0)))))
263 (provide 'nroff-mode
)
265 ;;; nroff-mode.el ends here