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emacs/lisp/textmodes/sgml-mode.el
1993-03-22 16:53:22 +00:00

269 lines
8.7 KiB
EmacsLisp

;;; sgml-mode.el --- SGML-editing mode
;; Copyright (C) 1992 Free Software Foundation, Inc.
;; Author: James Clark <jjc@clark.com>
;; Adapted-By: ESR
;; Keywords: 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 1, 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; see the file COPYING. If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
;;; Commentary:
;; Major mode for editing the SGML document-markup language.
;;
;; Some suggestions for your .emacs file:
;;
;; (autoload 'sgml-mode "sgml-mode" "SGML mode" t)
;;
;; (setq auto-mode-alist
;; (append (list (cons "\\.sgm$" 'sgml-mode)
;; (cons "\\.sgml$" 'sgml-mode)
;; (cons "\\.dtd$" 'sgml-mode))
;; auto-mode-alist))
;;; Code:
(provide 'sgml-mode)
(require 'compile)
;;; sgmls is a free SGML parser available from
;;; ftp.uu.net:pub/text-processing/sgml
;;; Its error messages can be parsed by next-error.
;;; The -s option suppresses output.
(defconst sgml-validate-command
"sgmls -s"
"*The command to validate an SGML document.
The file name of current buffer file name will be appended to this,
separated by a space.")
(defvar sgml-saved-validate-command nil
"The command last used to validate in this buffer.")
(defvar sgml-mode-map nil "Keymap for SGML mode")
(if sgml-mode-map
()
(setq sgml-mode-map (make-sparse-keymap))
(define-key sgml-mode-map ">" 'sgml-close-angle)
(define-key sgml-mode-map "/" 'sgml-slash)
(define-key sgml-mode-map "\C-c\C-v" 'sgml-validate))
(defun sgml-mode ()
"Major mode for editing SGML.
Makes > display the matching <. Makes / display matching /.
Use \\[sgml-validate] to validate your document with an SGML parser."
(interactive)
(kill-all-local-variables)
(setq local-abbrev-table text-mode-abbrev-table)
(use-local-map sgml-mode-map)
(setq mode-name "SGML")
(setq major-mode 'sgml-mode)
(make-local-variable 'paragraph-start)
;; A start or end tag by itself on a line separates a paragraph.
;; This is desirable because SGML discards a newline that appears
;; immediately after a start tag or immediately before an end tag.
(setq paragraph-start
"^[ \t\n]\\|\
\\(</?\\([A-Za-z]\\([-.A-Za-z0-9= \t\n]\\|\"[^\"]*\"\\|'[^']*'\\)*\\)?>$\\)")
(make-local-variable 'paragraph-separate)
(setq paragraph-separate
"^[ \t\n]*$\\|\
^</?\\([A-Za-z]\\([-.A-Za-z0-9= \t\n]\\|\"[^\"]*\"\\|'[^']*'\\)*\\)?>$")
(make-local-variable 'sgml-saved-validate-command)
(set-syntax-table text-mode-syntax-table)
(make-local-variable 'comment-start)
(setq comment-start "<!-- ")
(make-local-variable 'comment-end)
(setq comment-end " -->")
(make-local-variable 'comment-indent-function)
(setq comment-indent-function 'sgml-comment-indent)
(make-local-variable 'comment-start-skip)
;; This will allow existing comments within declarations to be
;; recognized.
(setq comment-start-skip "--[ \t]*")
(run-hooks 'text-mode-hook 'sgml-mode-hook))
(defun sgml-comment-indent ()
(if (and (looking-at "--")
(not (and (eq (char-after (1- (point))) ?!)
(eq (char-after (- (point) 2)) ?<))))
(progn
(skip-chars-backward " \t")
(max comment-column (1+ (current-column))))
0))
(defconst sgml-start-tag-regex
"<[A-Za-z]\\([-.A-Za-z0-9= \n\t]\\|\"[^\"]*\"\\|'[^']*'\\)*"
"Regular expression that matches a non-empty start tag.
Any terminating > or / is not matched.")
(defvar sgml-mode-markup-syntax-table nil
"Syntax table used for scanning SGML markup.")
(if sgml-mode-markup-syntax-table
()
(setq sgml-mode-markup-syntax-table (make-syntax-table))
(modify-syntax-entry ?< "(>" sgml-mode-markup-syntax-table)
(modify-syntax-entry ?> ")<" sgml-mode-markup-syntax-table)
(modify-syntax-entry ?- "_ 1234" sgml-mode-markup-syntax-table)
(modify-syntax-entry ?\' "\"" sgml-mode-markup-syntax-table))
(defconst sgml-angle-distance 4000
"*If non-nil, is the maximum distance to search for matching <
when > is inserted.")
(defun sgml-close-angle (arg)
"Insert > and display matching <."
(interactive "p")
(insert-char ?> arg)
(if (> arg 0)
(let ((oldpos (point))
(blinkpos))
(save-excursion
(save-restriction
(if sgml-angle-distance
(narrow-to-region (max (point-min)
(- (point) sgml-angle-distance))
oldpos))
;; See if it's the end of a marked section.
(and (> (- (point) (point-min)) 3)
(eq (char-after (- (point) 2)) ?\])
(eq (char-after (- (point) 3)) ?\])
(re-search-backward "<!\\[\\(-?[A-Za-z0-9. \t\n&;]\\|\
--\\([^-]\\|-[^-]\\)*--\\)*\\["
(point-min)
t)
(let ((msspos (point)))
(if (and (search-forward "]]>" oldpos t)
(eq (point) oldpos))
(setq blinkpos msspos))))
;; This handles cases where the > ends one of the following:
;; markup declaration starting with <! (possibly including a
;; declaration subset); start tag; end tag; SGML declaration.
(if blinkpos
()
(goto-char oldpos)
(condition-case ()
(let ((oldtable (syntax-table))
(parse-sexp-ignore-comments t))
(unwind-protect
(progn
(set-syntax-table sgml-mode-markup-syntax-table)
(setq blinkpos (scan-sexps oldpos -1)))
(set-syntax-table oldtable)))
(error nil))
(and blinkpos
(goto-char blinkpos)
(or
;; Check that it's a valid delimiter in context.
(not (looking-at
"<\\(\\?\\|/?[A-Za-z>]\\|!\\([[A-Za-z]\\|--\\)\\)"))
;; Check that it's not a net-enabling start tag
;; nor an unclosed start-tag.
(looking-at (concat sgml-start-tag-regex "[/<]"))
;; Nor an unclosed end-tag.
(looking-at "</[A-Za-z][-.A-Za-z0-9]*[ \t]*<"))
(setq blinkpos nil)))
(if blinkpos
()
;; See if it's the end of a processing instruction.
(goto-char oldpos)
(if (search-backward "<?" (point-min) t)
(let ((pipos (point)))
(if (and (search-forward ">" oldpos t)
(eq (point) oldpos))
(setq blinkpos pipos))))))
(if blinkpos
(progn
(goto-char blinkpos)
(if (pos-visible-in-window-p)
(sit-for 1)
(message "Matches %s"
(buffer-substring blinkpos
(progn (end-of-line)
(point)))))))))))
;;; I doubt that null end tags are used much for large elements,
;;; so use a small distance here.
(defconst sgml-slash-distance 1000
"*If non-nil, is the maximum distance to search for matching /
when / is inserted.")
(defun sgml-slash (arg)
"Insert / and display any previous matching /.
Two /s are treated as matching if the first / ends a net-enabling
start tag, and the second / is the corresponding null end tag."
(interactive "p")
(insert-char ?/ arg)
(if (> arg 0)
(let ((oldpos (point))
(blinkpos)
(level 0))
(save-excursion
(save-restriction
(if sgml-slash-distance
(narrow-to-region (max (point-min)
(- (point) sgml-slash-distance))
oldpos))
(if (and (re-search-backward sgml-start-tag-regex (point-min) t)
(eq (match-end 0) (1- oldpos)))
()
(goto-char (1- oldpos))
(while (and (not blinkpos)
(search-backward "/" (point-min) t))
(let ((tagend (save-excursion
(if (re-search-backward sgml-start-tag-regex
(point-min) t)
(match-end 0)
nil))))
(if (eq tagend (point))
(if (eq level 0)
(setq blinkpos (point))
(setq level (1- level)))
(setq level (1+ level)))))))
(if blinkpos
(progn
(goto-char blinkpos)
(if (pos-visible-in-window-p)
(sit-for 1)
(message "Matches %s"
(buffer-substring (progn
(beginning-of-line)
(point))
(1+ blinkpos))))))))))
(defun sgml-validate (command)
"Validate an SGML document.
Runs COMMAND, a shell command, in a separate process asynchronously
with output going to the buffer *compilation*.
You can then use the command \\[next-error] to find the next error message
and move to the line in the SGML document that caused it."
(interactive
(list (read-string "Validate command: "
(or sgml-saved-validate-command
(concat sgml-validate-command
" "
(let ((name (buffer-file-name)))
(and name
(file-name-nondirectory name))))))))
(setq sgml-saved-validate-command command)
(compile1 command "No more errors"))
;;; sgml-mode.el ends here