source/texk/web2c/cwebdir/cweb.el

   1 ;; This file contains extensions to GNU-Emacs, to wit:
   2 ; (1) some WEB-oriented functions that are also of general use
   3 ; (2) changes to the GNU-distributed TeX mode
   4 ; (3) definitions of simple WEB and CWEB modes
   5
   6 ; To use: Put this in your EMACS-lisp library and say (load-library "cweb")
   7 ; in your .emacs init file.
   8
   9 ; Contributed by Don Knuth, July 1990
  10
  11 ;; OK, here's part (1): some WEB-oriented functions whose main purpose is
  12 ; to maintain a stack of module names that are "pending" as you are writing
  13 ; a program. When you first think of a module that needs to be written later,
  14 ; put it into the pending list (by typing CTL-Z instead of @> after the
  15 ; name). Later you can say CTL-\ to retrieve a pending name (and if
  16 ; you want to cycle through the pending names, ESC-y after CTL-\ will
  17 ; do it, just as ESC-y works after a yank).
  18 ; After you've said CTL-\, the current region is the name just removed from
  19 ; the pending list. If you change your mind, you can put it back again by
  20 ; saying ESC-\. If you had put it into the pending list by mistake, you
  21 ; can get rid of it by using the normal CTL-W operation (kill-region).
  22 ; The following code binds the new commands to CTL-Z, CTL-\, and ESC-\
  23 ; in all modes. You may prefer other bindings, of course.
  24 ; CTL-Z is normally "suspend emacs", but it is best not used when emacs
  25 ; has its own window as it usually does nowadays; if you need the
  26 ; old CTL-Z, you might rather bind it to CTL-X CTL-Z.
  27 ; CTL-\ is normally undefined.
  28 ; ESC-\ is normally "delete space", but ESC-space DEL does that easily too.
  29
  30 (defvar pending-list nil
  31  "List of strings (usually WEB module names) still pending.")
  32
  33 (defun into-pending-list (beg end)
  34  "Copy region into pending-list."
  35  (interactive "r")
  36  (indicate-region)
  37  (setq pending-list (cons (buffer-substring beg end) pending-list)))
  38
  39 (defun new-module-name-pending ()
  40  "Insert @> to complete a module name, then put it into pending-list."
  41  (interactive)
  42  (insert "@>")
  43  (push-mark)
  44  (if (search-backward "@<" nil t)
  45      (progn
  46        (exchange-point-and-mark)
  47        (into-pending-list (point) (mark))
  48        )
  49    (message "There's no @< to begin the module name!")))
  50 (global-set-key "\C-z" 'new-module-name-pending)
  51
  52 (defun pop-pending-list (arg)
  53  "Remove first element of pending-list and insert it as current region.
  54 With argument, put point at left; otherwise point will follow the insertion.
  55 Say \\[new-yank-pop] to replace this by another element of the list.
  56 Say \\[into-pending-list] to put it back in the list."
  57  (interactive "*P")
  58  (if (consp pending-list)
  59      (progn
  60        (push-mark (point))
  61        (insert (car pending-list))
  62        (setq pending-list (cdr pending-list))
  63        (if arg
  64            (exchange-point-and-mark)))
  65    (message "Nothing is pending.")
  66    (setq this-command nil)))
  67 (global-set-key "\C-\\" 'pop-pending-list)
  68 (global-set-key "\M-\\" 'into-pending-list)
  69
  70 (defun new-yank-pop (arg)
  71  "If previous command was \\[pop-pending-list], pop a different string;
  72 otherwise do an ordinary Meta-y."
  73  (interactive "*p")
  74  (if (eq last-command 'pop-pending-list)
  75      (let (xch)
  76        (setq xch (< (point) (mark)))
  77        (setq pending-list (append pending-list
  78                                  (list (buffer-substring (point) (mark)))))
  79        (delete-region (point) (mark))
  80        (setq this-command 'pop-pending-list)
  81        (pop-pending-list xch))
  82    (yank-pop arg)))
  83 (global-set-key "\M-y" 'new-yank-pop)
  84
  85 (defun indicate-region ()
  86   "Bounce cursor to mark and back again"
  87   (let ((point-save (point)))
  88     (unwind-protect
  89         (progn (goto-char (mark))
  90                (sit-for 0 300)) ;; wait 300 milliseconds
  91       (goto-char point-save))))
  92
  93 ; I prefer to change the standard copy-region command to the following,
  94 ; which gives me visual feedback about what I've copied to the kill ring:
  95 (defun indicate-and-copy-region (beg end)
  96   "Indicate current region, then copy it to the kill ring."
  97   (interactive "r")(indicate-region)(copy-region-as-kill beg end))
  98 (global-set-key "\M-w" 'indicate-and-copy-region)
  99
 100 ; Here's another convenient command, bound to the usually unused ESC-".
 101 (defun ditto (arg)
 102   "Copy ARG characters from the line above."
 103   (interactive "*p")
 104   (let (ch)
 105     (while (> arg 0)
 106       (setq temporary-goal-column (current-column))
 107       (save-excursion
 108         (previous-line 1)
 109         (setq ch (following-char)))
 110       (insert ch)
 111       (setq arg (1- arg)))))
 112 (global-set-key "\M-\"" 'ditto)
 113
 114 ;; OK, here's part (2): Changes to TeX mode.
 115 ; The WEB modes below are very much like TeX mode, but some improvements were
 116 ; desirable in TeX mode:
 117 ; I made newline act as it does in indented-text mode, since this
 118 ; works nicely for both TeX and WEB (Pascal or C code).
 119 ; I made RET check for unmatched delimiters if it ends a paragraph.
 120 ; Otherwise TeX mode remains as it was before.
 121
 122 (setq TeX-mode-map (make-sparse-keymap))
 123 (define-key TeX-mode-map "\C-c\C-k" 'TeX-kill-job)
 124 (define-key TeX-mode-map "\C-c\C-l" 'TeX-recenter-output-buffer)
 125 (define-key TeX-mode-map "\C-c\C-q" 'TeX-show-print-queue)
 126 (define-key TeX-mode-map "\C-c\C-p" 'TeX-print)
 127 (define-key TeX-mode-map "\"" 'TeX-insert-quote)
 128 (define-key TeX-mode-map "\e}" 'up-list)
 129 (define-key TeX-mode-map "\e{" 'TeX-insert-braces)
 130 (define-key TeX-mode-map "\C-c\C-r" 'TeX-region)
 131 (define-key TeX-mode-map "\C-c\C-b" 'TeX-buffer)
 132 (define-key TeX-mode-map "\C-c\C-f" 'TeX-close-LaTeX-block)
 133 (define-key TeX-mode-map "\r" 'TeX-newline)
 134 (define-key TeX-mode-map "\t" 'indent-relative)
 135 (setq TeX-mode-hook '(lambda ()
 136   (make-local-variable 'indent-line-function)
 137   (setq indent-line-function 'indent-relative-maybe)))
 138
 139 (defun TeX-newline (arg)
 140 "If previous character is newline and no ARG, check for unbalanced braces
 141 and/or dollar signs in previous paragraph. If ARG is \\[universal-argument],
 142 do a single newline; otherwise do ordinary newline."
 143  (interactive "*P")
 144  (if (and (eq (preceding-char) ?\n) (not arg))
 145      (TeX-check-paragraph)
 146    (if (listp arg)
 147        (newline)
 148      (newline arg))))
 149
 150 (defun TeX-check-paragraph ()
 151 "Insert a newline following a newline, breaking a paragraph for TeX.
 152 Check for mismatched delimiters in paragraph being terminated."
 153   (interactive)
 154   (if (TeX-validate-paragraph
 155            (save-excursion
 156              (search-backward "\n\n" nil 'move)
 157              (point))
 158            (point))
 159       (insert ?\n)
 160     (insert ?\n)
 161     (error "Mismatched delimiters in that paragraph?")))
 162
 163 ;; and now, part (3): WEB and CWEB modes.
 164 ; These are like plain TeX mode except that the automatic conversion of
 165 ; " to `` or '' is disabled. (Personally I never liked that feature anyway,
 166 ; since it's easy to get used to typing `` and ''. In WEB modes, the
 167 ; feature soon becomes intolerable, unless you never use string constants!)
 168 ; Another thing distinguishing WEB mode from TeX is ESC-p and ESC-n, to
 169 ; move to previous or next module. These keys are usually unbound, except
 170 ; when processing email.
 171
 172 (defun forward-module (arg)
 173 "Advance past next WEB module beginning; with ARG, repeat ARG times."
 174  (interactive "p")
 175  (move-to-module arg))
 176 (defun backward-module (arg)
 177 "Advance to previous WEB module beginning; with ARG, repeat ARG times."
 178  (interactive "p")
 179  (move-to-module (- arg)))
 180 (defun move-to-module (arg)
 181  (while (> arg 0)
 182    (re-search-forward "@ \\|@\\*\\|@\n")
 183    (setq arg (1- arg)))
 184  (while (< arg 0)
 185    (re-search-backward "@ \\|@\\*\\|@\n")
 186    (setq arg (1+ arg))))
 187
 188 (defun web-mode ()
 189   "Major mode like TeX mode plus \\[forward-module] and \\[backward-module]
 190 for relative module movement. The automatic \" feature is disabled."
 191   (interactive)
 192   (plain-tex-mode)
 193   (local-set-key "\M-n" 'forward-module)
 194   (local-set-key "\M-p" 'backward-module)
 195   (local-set-key "\"" 'self-insert-command)
 196   (setq mode-name "WEB")
 197   (setq major-mode 'web-mode)
 198   (run-hooks 'web-mode-hook))
 199 (setq auto-mode-alist (cons '("\\.web$" . web-mode) auto-mode-alist))
 200
 201 (defun cweb-mode ()
 202   "Major mode like TeX mode plus \\[forward-module] and \\[backward-module]
 203 for relative module movement. The automatic \" feature is disabled."
 204   (interactive)
 205   (plain-tex-mode)
 206   (local-set-key "\M-n" 'forward-module)
 207   (local-set-key "\M-p" 'backward-module)
 208   (local-set-key "\"" 'self-insert-command)
 209   (setq comment-start nil)
 210   (modify-syntax-entry ?% "@")
 211   (setq mode-name "CWEB")
 212   (setq major-mode 'cweb-mode)
 213   (run-hooks 'cweb-mode-hook))
 214 (setq auto-mode-alist (cons '("\\.w$" . cweb-mode) auto-mode-alist))
 215 (setq auto-mode-alist (cons '("\\.ch$" . cweb-mode) auto-mode-alist))