lisp/mim-mode.el

   1 ;; Mim (MDL in MDL) mode.
   2 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   3 ;; Principal author K. Shane Hartman
   4
   5 ;; This file is part of GNU Emacs.
   6
   7 ;; GNU Emacs is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the GNU General Public License as published by
   9 ;; the Free Software Foundation; either version 1, or (at your option)
  10 ;; any later version.
  11
  12 ;; GNU Emacs is distributed in the hope that it will be useful,
  13 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ;; GNU General Public License for more details.
  16
  17 ;; You should have received a copy of the GNU General Public License
  18 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  19 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21
  22 (autoload 'fast-syntax-check-mim "mim-syntax"
  23           "Checks Mim syntax quickly.
  24 Answers correct or incorrect, cannot point out the error context."
  25           t)
  26
  27 (autoload 'slow-syntax-check-mim "mim-syntax"
  28           "Check Mim syntax slowly.
  29 Points out the context of the error, if the syntax is incorrect."
  30           t)
  31
  32 (defvar mim-mode-hysterical-bindings t
  33   "*Non-nil means bind list manipulation commands to Meta keys as well as
  34 Control-Meta keys for historical reasons.  Otherwise, only the latter keys
  35 are bound.")
  36
  37 (defvar mim-mode-map nil)
  38
  39 (defvar mim-mode-syntax-table nil)
  40
  41 (if mim-mode-syntax-table
  42     ()
  43   (let ((i -1))
  44     (setq mim-mode-syntax-table (make-syntax-table))
  45     (while (< i ?\ )
  46       (modify-syntax-entry (setq i (1+ i)) "    " mim-mode-syntax-table))
  47     (while (< i 127)
  48       (modify-syntax-entry (setq i (1+ i)) "_   " mim-mode-syntax-table))
  49     (setq i (1- ?a))
  50     (while (< i ?z)
  51       (modify-syntax-entry (setq i (1+ i)) "w   " mim-mode-syntax-table))
  52     (setq i (1- ?A))
  53     (while (< i ?Z)
  54       (modify-syntax-entry (setq i (1+ i)) "w   " mim-mode-syntax-table))
  55     (setq i (1- ?0))
  56     (while (< i ?9)
  57       (modify-syntax-entry (setq i (1+ i)) "w   " mim-mode-syntax-table))
  58     (modify-syntax-entry ?:  "     " mim-mode-syntax-table) ; make : symbol delimiter
  59     (modify-syntax-entry ?,  "'    " mim-mode-syntax-table)
  60     (modify-syntax-entry ?.  "'    " mim-mode-syntax-table)
  61     (modify-syntax-entry ?'  "'    " mim-mode-syntax-table)
  62     (modify-syntax-entry ?`  "'    " mim-mode-syntax-table)
  63     (modify-syntax-entry ?~  "'    " mim-mode-syntax-table)
  64     (modify-syntax-entry ?\; "'    " mim-mode-syntax-table) ; comments are prefixed objects
  65     (modify-syntax-entry ?#  "'    " mim-mode-syntax-table)
  66     (modify-syntax-entry ?%  "'    " mim-mode-syntax-table)
  67     (modify-syntax-entry ?!  "'    " mim-mode-syntax-table)
  68     (modify-syntax-entry ?\" "\"   " mim-mode-syntax-table)
  69     (modify-syntax-entry ?\\ "\\   " mim-mode-syntax-table)
  70     (modify-syntax-entry ?\( "\()  " mim-mode-syntax-table)
  71     (modify-syntax-entry ?\< "\(>  " mim-mode-syntax-table)
  72     (modify-syntax-entry ?\{ "\(}  " mim-mode-syntax-table)
  73     (modify-syntax-entry ?\[ "\(]  " mim-mode-syntax-table)
  74     (modify-syntax-entry ?\) "\)(  " mim-mode-syntax-table)
  75     (modify-syntax-entry ?\> "\)<  " mim-mode-syntax-table)
  76     (modify-syntax-entry ?\} "\){  " mim-mode-syntax-table)
  77     (modify-syntax-entry ?\] "\)[  " mim-mode-syntax-table)))
  78
  79 (defconst mim-whitespace "\000- ")
  80
  81 (defvar mim-mode-hook nil
  82   "*User function run after mim mode initialization.  Usage:
  83 \(setq mim-mode-hook '(lambda () ... your init forms ...)).")
  84
  85 (define-abbrev-table 'mim-mode-abbrev-table nil)
  86
  87 (defconst indent-mim-function 'indent-mim-function
  88   "Controls (via properties) indenting of special forms.
  89 \(put 'FOO 'indent-mim-function n\), integer n, means lines inside
  90 <FOO ...> will be indented n spaces from start of form.
  91 \(put 'FOO 'indent-mim-function 'DEFINE\) is like above but means use
  92 value of mim-body-indent as offset from start of form.
  93 \(put 'FOO 'indent-mim-function <cons>\) where <cons> is a list or pointted list
  94 of integers, means indent each form in <FOO ...> by the amount specified
  95 in <cons>.  When <cons> is exhausted, indent remaining forms by
  96 `mim-body-indent' unless <cons> is a pointed list, in which case the last
  97 cdr is used.  Confused?  Here is an example:
  98 \(put 'FROBIT 'indent-mim-function '\(4 2 . 1\)\)
  99 <FROBIT
 100      <CHOMP-IT>
 101    <CHOMP-SOME-MORE>
 102   <DIGEST>
 103   <BELCH>
 104   ...>
 105 Finally, the property can be a function name (read the code).")
 106
 107 (defvar indent-mim-comment t
 108   "*Non-nil means indent string comments.")
 109
 110 (defvar mim-body-indent 2
 111   "*Amount to indent in special forms which have DEFINE property on
 112 `indent-mim-function'.")
 113
 114 (defvar indent-mim-arglist t
 115   "*nil means indent arglists like ordinary lists.
 116 t means strings stack under start of arglist and variables stack to
 117 right of them.  Otherwise, strings stack under last string (or start
 118 of arglist if none) and variables stack to right of them.
 119 Examples (for values 'stack, t, nil):
 120
 121 \(FOO \"OPT\" BAR             \(FOO \"OPT\" BAR            \(FOO \"OPT\" BAR
 122            BAZ MUMBLE                 BAZ MUMBLE      BAZ MUMBLE
 123      \"AUX\"                  \"AUX\"                     \"AUX\"
 124      BLETCH ...             BLETCH ...                BLETCH ...")
 125
 126 (put 'DEFINE 'indent-mim-function 'DEFINE)
 127 (put 'DEFMAC 'indent-mim-function 'DEFINE)
 128 (put 'BIND 'indent-mim-function 'DEFINE)
 129 (put 'PROG 'indent-mim-function 'DEFINE)
 130 (put 'REPEAT 'indent-mim-function 'DEFINE)
 131 (put 'CASE 'indent-mim-function 'DEFINE)
 132 (put 'FUNCTION 'indent-mim-function 'DEFINE)
 133 (put 'MAPF 'indent-mim-function 'DEFINE)
 134 (put 'MAPR 'indent-mim-function 'DEFINE)
 135 (put 'UNWIND 'indent-mim-function (cons (* 2 mim-body-indent) mim-body-indent))
 136
 137 (defvar mim-down-parens-only t
 138   "*nil means treat ADECLs and ATOM trailers like structures when
 139 moving down a level of structure.")
 140
 141 (defvar mim-stop-for-slop t
 142   "*Non-nil means {next previous}-mim-object consider any
 143 non-whitespace character in column 0 to be a toplevel object, otherwise
 144 only open paren syntax characters will be considered.")
 145
 146 (fset 'mdl-mode 'mim-mode)
 147
 148 (defun mim-mode ()
 149   "Major mode for editing Mim (MDL in MDL) code.
 150 Commands:
 151     If value of `mim-mode-hysterical-bindings' is non-nil, then following
 152 commands are assigned to escape keys as well (e.g. ESC f = ESC C-f).
 153 The default action is bind the escape keys.
 154 \\{mim-mode-map}
 155 Other Commands:
 156   Use \\[describe-function] to obtain documentation.
 157   replace-in-mim-object  find-mim-definition  fast-syntax-check-mim
 158   slow-syntax-check-mim  backward-down-mim-object  forward-up-mim-object
 159 Variables:
 160   Use \\[describe-variable] to obtain documentation.
 161   mim-mode-hook  indent-mim-comment  indent-mim-arglist  indent-mim-function
 162   mim-body-indent  mim-down-parens-only  mim-stop-for-slop
 163   mim-mode-hysterical-bindings
 164 Entry to this mode calls the value of mim-mode-hook if non-nil."
 165   (interactive)
 166   (kill-all-local-variables)
 167   (if (not mim-mode-map)
 168       (progn
 169         (setq mim-mode-map (make-sparse-keymap))
 170         (define-key mim-mode-map "\e\^o" 'open-mim-line)
 171         (define-key mim-mode-map "\e\^q" 'indent-mim-object)
 172         (define-key mim-mode-map "\e\^p" 'previous-mim-object)
 173         (define-key mim-mode-map "\e\^n" 'next-mim-object)
 174         (define-key mim-mode-map "\e\^a" 'beginning-of-DEFINE)
 175         (define-key mim-mode-map "\e\^e" 'end-of-DEFINE)
 176         (define-key mim-mode-map "\e\^t" 'transpose-mim-objects)
 177         (define-key mim-mode-map "\e\^u" 'backward-up-mim-object)
 178         (define-key mim-mode-map "\e\^d" 'forward-down-mim-object)
 179         (define-key mim-mode-map "\e\^h" 'mark-mim-object)
 180         (define-key mim-mode-map "\e\^k" 'forward-kill-mim-object)
 181         (define-key mim-mode-map "\e\^f" 'forward-mim-object)
 182         (define-key mim-mode-map "\e\^b" 'backward-mim-object)
 183         (define-key mim-mode-map "\e^" 'raise-mim-line)
 184         (define-key mim-mode-map "\e\\" 'fixup-whitespace)
 185         (define-key mim-mode-map "\177" 'backward-delete-char-untabify)
 186         (define-key mim-mode-map "\e\177" 'backward-kill-mim-object)
 187         (define-key mim-mode-map "\^j" 'newline-and-mim-indent)
 188         (define-key mim-mode-map "\e;" 'begin-mim-comment)
 189         (define-key mim-mode-map "\t" 'indent-mim-line)
 190         (define-key mim-mode-map "\e\t" 'indent-mim-object)
 191         (if (not mim-mode-hysterical-bindings)
 192             nil
 193           ;; i really hate this but too many people are accustomed to these.
 194           (define-key mim-mode-map "\e!" 'line-to-top-of-window)
 195           (define-key mim-mode-map "\eo" 'open-mim-line)
 196           (define-key mim-mode-map "\ep" 'previous-mim-object)
 197           (define-key mim-mode-map "\en" 'next-mim-object)
 198           (define-key mim-mode-map "\ea" 'beginning-of-DEFINE)
 199           (define-key mim-mode-map "\ee" 'end-of-DEFINE)
 200           (define-key mim-mode-map "\et" 'transpose-mim-objects)
 201           (define-key mim-mode-map "\eu" 'backward-up-mim-object)
 202           (define-key mim-mode-map "\ed" 'forward-down-mim-object)
 203           (define-key mim-mode-map "\ek" 'forward-kill-mim-object)
 204           (define-key mim-mode-map "\ef" 'forward-mim-object)
 205           (define-key mim-mode-map "\eb" 'backward-mim-object))))
 206   (use-local-map mim-mode-map)
 207   (set-syntax-table mim-mode-syntax-table)
 208   (make-local-variable 'paragraph-start)
 209   (setq paragraph-start (concat "^$\\|" page-delimiter))
 210   (make-local-variable 'paragraph-separate)
 211   (setq paragraph-separate paragraph-start)
 212   (make-local-variable 'paragraph-ignore-fill-prefix)
 213   (setq paragraph-ignore-fill-prefix t)
 214   ;; Most people use string comments.
 215   (make-local-variable 'comment-start)
 216   (setq comment-start ";\"")
 217   (make-local-variable 'comment-start-skip)
 218   (setq comment-start-skip ";\"")
 219   (make-local-variable 'comment-end)
 220   (setq comment-end "\"")
 221   (make-local-variable 'comment-column)
 222   (setq comment-column 40)
 223   (make-local-variable 'comment-indent-hook)
 224   (setq comment-indent-hook 'indent-mim-comment)
 225   ;; tell generic indenter how to indent.
 226   (make-local-variable 'indent-line-function)
 227   (setq indent-line-function 'indent-mim-line)
 228   ;; look for that paren
 229   (make-local-variable 'blink-matching-paren-distance)
 230   (setq blink-matching-paren-distance nil)
 231   ;; so people who dont like tabs can turn them off locally in indenter.
 232   (make-local-variable 'indent-tabs-mode)
 233   (setq indent-tabs-mode t)
 234   (setq local-abbrev-table mim-mode-abbrev-table)
 235   (setq major-mode 'mim-mode)
 236   (setq mode-name "Mim")
 237   (run-hooks 'mim-mode-hook))
 238
 239 (defun line-to-top-of-window ()
 240   "Move current line to top of window."
 241   (interactive)                         ; for lazy people
 242   (recenter 0))
 243
 244 (defun forward-mim-object (arg)
 245   "Move forward across Mim object.
 246 With ARG, move forward that many objects."
 247   (interactive "p")
 248   ;; this function is wierd because it emulates the behavior of the old
 249   ;; (gosling) mim-mode - if the arg is 1 and we are `inside' an ADECL,
 250   ;; more than one character into the ATOM part and not sitting on the
 251   ;; colon, then we move to the DECL part (just past colon) instead of
 252   ;; the end of the object (the entire ADECL).  otherwise, ADECL's are
 253   ;; atomic objects.  likewise for ATOM trailers.
 254   (if (= (abs arg) 1)
 255       (if (inside-atom-p)
 256           ;; Move to end of ATOM or to trailer (!) or to ADECL (:).
 257           (forward-sexp arg)
 258         ;; Either scan an sexp or move over one bracket.
 259         (forward-mim-objects arg t))
 260     ;; in the multi-object case, don't perform any magic.
 261     ;; treats ATOM trailers and ADECLs atomically, stops at unmatched
 262     ;; brackets with error.
 263     (forward-mim-objects arg)))
 264
 265 (defun inside-atom-p ()
 266   ;; Returns t iff inside an atom (takes account of trailers)
 267   (let ((c1 (preceding-char))
 268         (c2 (following-char)))
 269     (and (or (= (char-syntax c1) ?w) (= (char-syntax c1) ?_) (= c1 ?!))
 270          (or (= (char-syntax c2) ?w) (= (char-syntax c2) ?_) (= c2 ?!)))))
 271
 272 (defun forward-mim-objects (arg &optional skip-bracket-p)
 273   ;; Move over arg objects ignoring ADECLs and trailers.  If
 274   ;; skip-bracket-p is non-nil, then move over one bracket on error.
 275   (let ((direction (sign arg)))
 276     (condition-case conditions
 277         (while (/= arg 0)
 278           (forward-sexp direction)
 279           (if (not (inside-adecl-or-trailer-p direction))
 280               (setq arg (- arg direction))))
 281       (error (if (not skip-bracket-p)
 282                  (signal 'error (cdr conditions))
 283                (skip-mim-whitespace direction)
 284                (goto-char (+ (point) direction)))))
 285     ;; If we moved too far move back to first interesting character.
 286     (if (= (point) (buffer-end direction)) (skip-mim-whitespace (- direction)))))
 287
 288 (defun backward-mim-object (&optional arg)
 289   "Move backward across Mim object.
 290 With ARG, move backward that many objects."
 291   (interactive "p")
 292   (forward-mim-object (if arg (- arg) -1)))
 293
 294 (defun mark-mim-object (&optional arg)
 295   "Mark following Mim object.
 296 With ARG, mark that many following (preceding, ARG < 0) objects."
 297   (interactive "p")
 298   (push-mark (save-excursion (forward-mim-object (or arg 1)) (point))))
 299
 300 (defun forward-kill-mim-object (&optional arg)
 301   "Kill following Mim object.
 302 With ARG, kill that many objects."
 303   (interactive "*p")
 304   (kill-region (point) (progn (forward-mim-object (or arg 1)) (point))))
 305
 306 (defun backward-kill-mim-object (&optional arg)
 307   "Kill preceding Mim object.
 308 With ARG, kill that many objects."
 309   (interactive "*p")
 310   (forward-kill-mim-object (- (or arg 1))))
 311
 312 (defun raise-mim-line (&optional arg)
 313   "Raise following line, fixing up whitespace at join.
 314 With ARG raise that many following lines.
 315 A negative ARG will raise current line and previous lines."
 316   (interactive "*p")
 317   (let* ((increment (sign (or arg (setq arg 1))))
 318          (direction (if (> arg 0) 1 0)))
 319     (save-excursion
 320       (while (/= arg 0)
 321         ;; move over eol and kill it
 322         (forward-line direction)
 323         (delete-region (point) (1- (point)))
 324         (fixup-whitespace)
 325         (setq arg (- arg increment))))))
 326
 327 (defun forward-down-mim-object (&optional arg)
 328   "Move down a level of Mim structure forwards.
 329 With ARG, move down that many levels forwards (backwards, ARG < 0)."
 330   (interactive "p")
 331   ;; another wierdo - going down `inside' an ADECL or ATOM trailer
 332   ;; depends on the value of mim-down-parens-only.  if nil, treat
 333   ;; ADECLs and trailers as structured objects.
 334   (let ((direction (sign (or arg (setq arg 1)))))
 335     (if (and (= (abs arg) 1) (not mim-down-parens-only))
 336         (goto-char
 337           (save-excursion
 338             (skip-mim-whitespace direction)
 339             (if (> direction 0) (re-search-forward "\\s'*"))
 340             (or (and (let ((c (next-char direction)))
 341                        (or (= (char-syntax c) ?_)
 342                            (= (char-syntax c) ?w)))
 343                      (progn (forward-sexp direction)
 344                             (if (inside-adecl-or-trailer-p direction)
 345                                 (point))))
 346                 (scan-lists (point) direction -1)
 347                 (buffer-end direction))))
 348       (while (/= arg 0)
 349         (goto-char (or (scan-lists (point) direction -1) (buffer-end direction)))
 350         (setq arg (- arg direction))))))
 351
 352 (defun backward-down-mim-object (&optional arg)
 353   "Move down a level of Mim structure backwards.
 354 With ARG, move down that many levels backwards (forwards, ARG < 0)."
 355   (interactive "p")
 356   (forward-down-mim-object (if arg (- arg) -1)))
 357
 358 (defun forward-up-mim-object (&optional arg)
 359   "Move up a level of Mim structure forwards
 360 With ARG, move up that many levels forwards (backwards, ARG < 0)."
 361   (interactive "p")
 362   (let ((direction (sign (or arg (setq arg 1)))))
 363     (while (/= arg 0)
 364       (goto-char (or (scan-lists (point) direction 1) (buffer-end arg)))
 365       (setq arg (- arg direction)))
 366     (if (< direction 0) (backward-prefix-chars))))
 367
 368 (defun backward-up-mim-object (&optional arg)
 369   "Move up a level of Mim structure backwards
 370 With ARG, move up that many levels backwards (forwards, ARG > 0)."
 371   (interactive "p")
 372   (forward-up-mim-object (if arg (- arg) -1)))
 373
 374 (defun replace-in-mim-object (old new)
 375   "Replace string in following Mim object."
 376   (interactive "*sReplace in object: \nsReplace %s with: ")
 377   (save-restriction
 378     (narrow-to-region (point) (save-excursion (forward-mim-object 1) (point)))
 379     (replace-string old new)))
 380
 381 (defun transpose-mim-objects (&optional arg)
 382   "Transpose Mim objects around point.
 383 With ARG, transpose preceding object that many times with following objects.
 384 A negative ARG will transpose backwards."
 385   (interactive "*p")
 386   (transpose-subr 'forward-mim-object (or arg 1)))
 387
 388 (defun beginning-of-DEFINE (&optional arg move)
 389   "Move backward to beginning of surrounding or previous toplevel Mim form.
 390 With ARG, do it that many times.  Stops at last toplevel form seen if buffer
 391 end is reached."
 392   (interactive "p")
 393   (let ((direction (sign (or arg (setq arg 1)))))
 394     (if (not move) (setq move t))
 395     (if (< direction 0) (goto-char (1+ (point))))
 396     (while (and (/= arg 0) (re-search-backward "^<" nil move direction))
 397       (setq arg (- arg direction)))
 398     (if (< direction 0)
 399         (goto-char (1- (point))))))
 400
 401 (defun end-of-DEFINE (&optional arg)
 402   "Move forward to end of surrounding or next toplevel mim form.
 403 With ARG, do it that many times.  Stops at end of last toplevel form seen
 404 if buffer end is reached."
 405   (interactive "p")
 406   (if (not arg) (setq arg 1))
 407   (if (< arg 0)
 408       (beginning-of-DEFINE (- (1- arg)))
 409     (if (not (looking-at "^<")) (setq arg (1+ arg)))
 410     (beginning-of-DEFINE (- arg) 'move)
 411     (beginning-of-DEFINE 1))
 412   (forward-mim-object 1)
 413   (forward-line 1))
 414
 415 (defun next-mim-object (&optional arg)
 416   "Move to beginning of next toplevel Mim object.
 417 With ARG, do it that many times.  Stops at last object seen if buffer end
 418 is reached."
 419   (interactive "p")
 420   (let ((search-string (if mim-stop-for-slop "^\\S " "^\\s("))
 421         (direction (sign (or arg (setq arg 1)))))
 422     (if (> direction 0)
 423         (goto-char (1+ (point))))               ; no error if end of buffer
 424     (while (and (/= arg 0)
 425                 (re-search-forward search-string nil t direction))
 426       (setq arg (- arg direction)))
 427     (if (> direction 0)
 428         (goto-char (1- (point))))               ; no error if beginning of buffer
 429     ;; scroll to top of window if moving forward and end not visible.
 430     (if (not (or (< direction 0)
 431                  (save-excursion (forward-mim-object 1)
 432                                  (pos-visible-in-window-p (point)))))
 433         (recenter 0))))
 434
 435 (defun previous-mim-object (&optional arg)
 436   "Move to beginning of previous toplevel Mim object.
 437 With ARG do it that many times.  Stops at last object seen if buffer end
 438 is reached."
 439   (interactive "p")
 440   (next-mim-object (- (or arg 1))))
 441
 442 (defun calculate-mim-indent (&optional parse-start)
 443   "Calculate indentation for Mim line.  Returns column."
 444   (save-excursion                       ; some excursion, huh, toto?
 445     (beginning-of-line)
 446     (let ((indent-point (point)) retry state containing-sexp last-sexp
 447           desired-indent start peek where paren-depth)
 448       (if parse-start
 449           (goto-char parse-start)       ; should be containing environment
 450         (catch 'from-the-top
 451           ;; find a place to start parsing.  going backwards is fastest.
 452           ;; forward-sexp signals error on encountering unmatched open.
 453           (setq retry t)
 454           (while retry
 455             (condition-case nil (forward-sexp -1) (error (setq retry nil)))
 456             (if (looking-at ".?[ \t]*\"")
 457                 ;; cant parse backward in presence of strings, go forward.
 458                 (progn
 459                   (goto-char indent-point)
 460                   (re-search-backward "^\\s(" nil 'move 1)  ; to top of object
 461                   (throw 'from-the-top nil)))
 462             (setq retry (and retry (/= (current-column) 0))))
 463           (skip-chars-backward mim-whitespace)
 464           (if (not (bobp)) (forward-char -1))     ; onto unclosed open
 465           (backward-prefix-chars)))
 466       ;; find outermost containing sexp if we started inside an sexp.
 467       (while (< (point) indent-point)
 468         (setq state (parse-partial-sexp (point) indent-point 0)))
 469       ;; find usual column to indent under (not in string or toplevel).
 470       ;; on termination, state will correspond to containing environment
 471       ;; (if retry is nil), where will be position of character to indent
 472       ;; under normally, and desired-indent will be the column to indent to
 473       ;; except if inside form, string, or at toplevel.  point will be in
 474       ;; in column to indent to unless inside string.
 475       (setq retry t)
 476       (while (and retry (setq paren-depth (car state)) (> paren-depth 0))
 477         ;; find innermost containing sexp.
 478         (setq retry nil)
 479         (setq last-sexp (car (nthcdr 2 state)))
 480         (setq containing-sexp (car (cdr state)))
 481         (goto-char (1+ containing-sexp))          ; to last unclosed open
 482         (if (and last-sexp (> last-sexp (point)))
 483             ;; is the last sexp a containing sexp?
 484             (progn (setq peek (parse-partial-sexp last-sexp indent-point 0))
 485                    (if (setq retry (car (cdr peek))) (setq state peek))))
 486         (if retry
 487             nil
 488           (setq where (1+ containing-sexp))   ; innermost containing sexp
 489           (goto-char where)
 490           (cond
 491            ((not last-sexp)                   ; indent-point after bracket
 492             (setq desired-indent (current-column)))
 493            ((= (preceding-char) ?\<)          ; it's a form
 494             (cond ((> (progn (forward-sexp 1) (point)) last-sexp)
 495                    (goto-char where))         ; only one frob
 496                   ((> (save-excursion (forward-line 1) (point)) last-sexp)
 497                    (skip-chars-forward " \t") ; last-sexp is on same line
 498                    (setq where (point)))              ; as containing-sexp
 499                   ((progn
 500                      (goto-char last-sexp)
 501                      (beginning-of-line)
 502                      (parse-partial-sexp (point) last-sexp 0 t)
 503                      (or (= (point) last-sexp)
 504                          (save-excursion
 505                            (= (car (parse-partial-sexp (point) last-sexp 0))
 506                               0))))
 507                    (backward-prefix-chars)    ; last-sexp 1st on line or 1st
 508                    (setq where (point)))        ; frob on that line level 0
 509                   (t (goto-char where))))     ; punt, should never occur
 510            ((and indent-mim-arglist           ; maybe hack arglist
 511                  (= (preceding-char) ?\()     ; its a list
 512                  (save-excursion              ; look for magic atoms
 513                    (setq peek 0)              ; using peek as counter
 514                    (forward-char -1)          ; back over containing paren
 515                    (while (and (< (setq peek (1+ peek)) 6)
 516                                (condition-case nil
 517                                    (progn (forward-sexp -1) t)
 518                                  (error nil))))
 519                    (and (< peek 6) (looking-at "DEFINE\\|DEFMAC\\|FUNCTION"))))
 520             ;; frobs stack under strings they belong to or under first
 521             ;; frob to right of strings they belong to unless luser has
 522             ;; frob (non-string) on preceding line with different
 523             ;; indentation.  strings stack under start of arglist unless
 524             ;; mim-indent-arglist is not t, in which case they stack
 525             ;; under the last string, if any, else the start of the arglist.
 526             (let ((eol 0) last-string)
 527               (while (< (point) last-sexp)      ; find out where the strings are
 528                 (skip-chars-forward mim-whitespace last-sexp)
 529                 (if (> (setq start (point)) eol)
 530                     (progn                    ; simultaneously keeping track
 531                       (setq where (min where start))
 532                       (end-of-line)           ; of indentation of first frob
 533                       (setq eol (point))              ; on each line
 534                       (goto-char start)))
 535                 (if (= (following-char) ?\")
 536                     (progn (setq last-string (point))
 537                            (forward-sexp 1)
 538                            (if (= last-string last-sexp)
 539                                (setq where last-sexp)
 540                              (skip-chars-forward mim-whitespace last-sexp)
 541                              (setq where (point))))
 542                   (forward-sexp 1)))
 543               (goto-char indent-point)             ; if string is first on
 544               (skip-chars-forward " \t" (point-max)) ; line we are indenting, it
 545               (if (= (following-char) ?\")         ; goes under arglist start
 546                   (if (and last-string (not (equal indent-mim-arglist t)))
 547                       (setq where last-string)     ; or under last string.
 548                     (setq where (1+ containing-sexp)))))
 549             (goto-char where)
 550             (setq desired-indent (current-column)))
 551            (t                                 ; plain vanilla structure
 552             (cond ((> (save-excursion (forward-line 1) (point)) last-sexp)
 553                    (skip-chars-forward " \t") ; last-sexp is on same line
 554                    (setq where (point)))              ; as containing-sexp
 555                   ((progn
 556                      (goto-char last-sexp)
 557                      (beginning-of-line)
 558                      (parse-partial-sexp (point) last-sexp 0 t)
 559                      (or (= (point) last-sexp)
 560                          (save-excursion
 561                            (= (car (parse-partial-sexp (point) last-sexp 0))
 562                               0))))
 563                      (backward-prefix-chars)  ; last-sexp 1st on line or 1st
 564                      (setq where (point)))      ; frob on that line level 0
 565                   (t (goto-char where)))      ; punt, should never occur
 566             (setq desired-indent (current-column))))))
 567       ;; state is innermost containing environment unless toplevel or string.
 568       (if (car (nthcdr 3 state))              ; inside string
 569           (progn
 570             (if last-sexp                     ; string must be next
 571                 (progn (goto-char last-sexp)
 572                        (forward-sexp 1)
 573                        (search-forward "\"")
 574                        (forward-char -1))
 575               (goto-char indent-point)        ; toplevel string, look for it
 576               (re-search-backward "[^\\]\"")
 577               (forward-char 1))
 578             (setq start (point))                      ; opening double quote
 579             (skip-chars-backward " \t")
 580             (backward-prefix-chars)
 581             ;; see if the string is really a comment.
 582             (if (and (looking-at ";[ \t]*\"") indent-mim-comment)
 583                 ;; it's a comment, line up under the start unless disabled.
 584                 (goto-char (1+ start))
 585               ;; it's a string, dont mung the indentation.
 586               (goto-char indent-point)
 587               (skip-chars-forward " \t"))
 588             (setq desired-indent (current-column))))
 589       ;; point is sitting in usual column to indent to and if retry is nil
 590       ;; then state corresponds to containing environment.  if desired
 591       ;; indentation not determined, we are inside a form, so call hook.
 592       (or desired-indent
 593           (and indent-mim-function
 594                (not retry)
 595                (setq desired-indent
 596                      (funcall indent-mim-function state indent-point)))
 597           (setq desired-indent (current-column)))
 598       (goto-char indent-point)          ; back to where we started
 599       desired-indent)))                 ; return column to indent to
 600
 601 (defun indent-mim-function (state indent-point)
 602   "Compute indentation for Mim special forms.  Returns column or nil."
 603   (let ((containing-sexp (car (cdr state))) (current-indent (point)))
 604     (save-excursion
 605       (goto-char (1+ containing-sexp))
 606       (backward-prefix-chars)
 607       ;; make sure we are looking at a symbol.  if so, see if it is a special
 608       ;; symbol.  if so, add the special indentation to the indentation of
 609       ;; the start of the special symbol, unless the property is not
 610       ;; an integer and not nil (in this case, call the property, it must
 611       ;; be a function which returns the appropriate indentation or nil and
 612       ;; does not change the buffer).
 613       (if (looking-at "\\sw\\|\\s_")
 614           (let* ((start (current-column))
 615                  (function
 616                   (intern-soft (buffer-substring (point)
 617                                                  (progn (forward-sexp 1)
 618                                                         (point)))))
 619                  (method (get function 'indent-mim-function)))
 620             (if (or (if (equal method 'DEFINE) (setq method mim-body-indent))
 621                     (integerp method))
 622                 ;; only use method if its first line after containing-sexp.
 623                 ;; we could have done this in calculate-mim-indent, but someday
 624                 ;; someone might want to format frobs in a special form based
 625                 ;; on position instead of indenting uniformly (like lisp if),
 626                 ;; so preserve right for posterity.  if not first line,
 627                 ;; calculate-mim-indent already knows right indentation -
 628                 ;; give luser chance to change indentation manually by changing
 629                 ;; 1st line after containing-sexp.
 630                 (if (> (progn (forward-line 1) (point)) (car (nthcdr 2 state)))
 631                     (+ method start))
 632               (goto-char current-indent)
 633               (if (consp method)
 634                   ;; list or pointted list of explicit indentations
 635                   (indent-mim-offset state indent-point)
 636                 (if (and (symbolp method) (fboundp method))
 637                     ;; luser function - s/he better know what's going on.
 638                     ;; should take state and indent-point as arguments - for
 639                     ;; description of state, see parse-partial-sexp
 640                     ;; documentation the function is guaranteed the following:
 641                     ;; (1) state describes the closest surrounding form,
 642                     ;; (2) indent-point is the beginning of the line being
 643                     ;; indented, (3) point points to char in column that would
 644                     ;; normally be used for indentation, (4) function is bound
 645                     ;; to the special ATOM.  See indent-mim-offset for example
 646                     ;; of a special function.
 647                     (funcall method state indent-point)))))))))
 648
 649 (defun indent-mim-offset (state indent-point)
 650   ;; offset forms explicitly according to list of indentations.
 651   (let ((mim-body-indent mim-body-indent)
 652         (indentations (get function 'indent-mim-function))
 653         (containing-sexp (car (cdr state)))
 654         (last-sexp (car (nthcdr 2 state)))
 655         indentation)
 656     (goto-char (1+ containing-sexp))
 657     ;; determine wheich of the indentations to use.
 658     (while (and (< (point) indent-point)
 659                 (condition-case nil
 660                     (progn (forward-sexp 1)
 661                            (parse-partial-sexp (point) indent-point 1 t))
 662                   (error nil)))
 663       (skip-chars-backward " \t")
 664       (backward-prefix-chars)
 665       (if (= (following-char) ?\;)
 666           nil                                       ; ignore comments
 667         (setq indentation (car indentations))
 668         (if (integerp (setq indentations (cdr indentations)))
 669             ;; if last cdr is integer, that is indentation to use for all
 670             ;; all the rest of the forms.
 671             (progn (setq mim-body-indent indentations)
 672                    (setq indentations nil)))))
 673     (goto-char (1+ containing-sexp))
 674     (+ (current-column) (or indentation mim-body-indent))))
 675
 676 (defun indent-mim-comment (&optional start)
 677   "Indent a one line (string) Mim comment following object, if any."
 678   (let* ((old-point (point)) (eol (progn (end-of-line) (point))) state last-sexp)
 679     ;; this function assumes that comment indenting is enabled.  it is caller's
 680     ;; responsibility to check the indent-mim-comment flag before calling.
 681     (beginning-of-line)
 682     (catch 'no-comment
 683       (setq state (parse-partial-sexp (point) eol))
 684       ;; determine if there is an existing regular comment.  a `regular'
 685       ;; comment is defined as a commented string which is the last thing
 686       ;; on the line and does not extend beyond the end of the line.
 687       (if (or (not (setq last-sexp (car (nthcdr 2 state))))
 688               (car (nthcdr 3 state)))
 689           ;; empty line or inside string (multiple line).
 690           (throw 'no-comment nil))
 691       ;; could be a comment, but make sure its not the only object.
 692       (beginning-of-line)
 693       (parse-partial-sexp (point) eol 0 t)
 694       (if (= (point) last-sexp)
 695           ;; only one object on line
 696           (throw 'no-comment t))
 697       (goto-char last-sexp)
 698       (skip-chars-backward " \t")
 699       (backward-prefix-chars)
 700       (if (not (looking-at ";[ \t]*\""))
 701           ;; aint no comment
 702           (throw 'no-comment nil))
 703       ;; there is an existing regular comment
 704       (delete-horizontal-space)
 705       ;; move it to comment-column if possible else to tab-stop
 706       (if (< (current-column) comment-column)
 707           (indent-to comment-column)
 708         (tab-to-tab-stop)))
 709     (goto-char old-point)))
 710
 711 (defun indent-mim-line ()
 712   "Indent line of Mim code."
 713   (interactive "*")
 714   (let* ((position (- (point-max) (point)))
 715          (bol (progn (beginning-of-line) (point)))
 716          (indent (calculate-mim-indent)))
 717     (skip-chars-forward " \t")
 718     (if (/= (current-column) indent)
 719         (progn (delete-region bol (point)) (indent-to indent)))
 720     (if (> (- (point-max) position) (point)) (goto-char (- (point-max) position)))))
 721
 722 (defun newline-and-mim-indent ()
 723   "Insert newline at point and indent."
 724   (interactive "*")
 725   ;; commented code would correct indentation of line in arglist which
 726   ;; starts with string, but it would indent every line twice.  luser can
 727   ;; just say tab after typing string to get same effect.
 728   ;(if indent-mim-arglist (indent-mim-line))
 729   (newline)
 730   (indent-mim-line))
 731
 732 (defun open-mim-line (&optional lines)
 733   "Insert newline before point and indent.
 734 With ARG insert that many newlines."
 735   (interactive "*p")
 736   (beginning-of-line)
 737   (let ((indent (calculate-mim-indent)))
 738     (while (> lines 0)
 739       (newline)
 740       (forward-line -1)
 741       (indent-to indent)
 742       (setq lines (1- lines)))))
 743
 744 (defun indent-mim-object (&optional dont-indent-first-line)
 745   "Indent object following point and all lines contained inside it.
 746 With ARG, idents only contained lines (skips first line)."
 747   (interactive "*P")
 748   (let (end bol indent start)
 749     (save-excursion (parse-partial-sexp (point) (point-max) 0 t)
 750                     (setq start (point))
 751                     (forward-sexp 1)
 752                     (setq end (- (point-max) (point))))
 753     (save-excursion
 754       (if (not dont-indent-first-line) (indent-mim-line))
 755       (while (progn (forward-line 1) (> (- (point-max) (point)) end))
 756         (setq indent (calculate-mim-indent start))
 757         (setq bol (point))
 758         (skip-chars-forward " \t")
 759         (if (/= indent (current-column))
 760             (progn (delete-region bol (point)) (indent-to indent)))
 761         (if indent-mim-comment (indent-mim-comment))))))
 762
 763 (defun find-mim-definition (name)
 764   "Search for definition of function, macro, or gfcn.
 765 You need type only enough of the name to be unambiguous."
 766   (interactive "sName: ")
 767   (let (where)
 768     (save-excursion
 769       (goto-char (point-min))
 770       (condition-case nil
 771           (progn
 772             (re-search-forward
 773              (concat "^<\\(DEFINE\\|\\DEFMAC\\|FCN\\|GFCN\\)\\([ \t]*\\)"
 774                      name))
 775             (setq where (point)))
 776         (error (error "Can't find %s" name))))
 777     (if where
 778         (progn (push-mark)
 779                (goto-char where)
 780                (beginning-of-line)
 781                (recenter 0)))))
 782
 783 (defun begin-mim-comment ()
 784   "Move to existing comment or insert empty comment."
 785   (interactive "*")
 786   (let* ((eol (progn (end-of-line) (point)))
 787          (bol (progn (beginning-of-line) (point))))
 788     ;; check for existing comment first.
 789     (if (re-search-forward ";[ \t]*\"" eol t)
 790         ;; found it.  indent if desired and go there.
 791         (if indent-mim-comment
 792             (let ((where (- (point-max) (point))))
 793               (indent-mim-comment)
 794               (goto-char (- (point-max) where))))
 795       ;; nothing there, make a comment.
 796       (let (state last-sexp)
 797         ;; skip past all the sexps on the line
 798         (goto-char bol)
 799         (while (and (equal (car (setq state (parse-partial-sexp (point) eol 0)))
 800                            0)
 801                     (car (nthcdr 2 state)))
 802           (setq last-sexp (car (nthcdr 2 state))))
 803         (if (car (nthcdr 3 state))
 804             nil                                     ; inside a string, punt
 805       (delete-region (point) eol)                           ; flush trailing whitespace
 806       (if (and (not last-sexp) (equal (car state) 0))
 807           (indent-to (calculate-mim-indent))        ; empty, indent like code
 808         (if (> (current-column) comment-column)     ; indent to comment column
 809             (tab-to-tab-stop)                       ; unless past it, else to
 810           (indent-to comment-column)))              ; tab-stop
 811       ;; if luser changes comment-{start end} to something besides semi
 812       ;; followed by zero or more whitespace characters followed by string
 813       ;; delimiters, the code above fails to find existing comments, but as
 814       ;; taa says, `let the losers lose'.
 815       (insert comment-start)
 816       (save-excursion (insert comment-end)))))))
 817
 818 (defun skip-mim-whitespace (direction)
 819   (if (>= direction 0)
 820       (skip-chars-forward mim-whitespace (point-max))
 821     (skip-chars-backward mim-whitespace (point-min))))
 822
 823 (defun inside-adecl-or-trailer-p (direction)
 824   (if (>= direction 0)
 825       (looking-at ":\\|!-")
 826     (or (= (preceding-char) ?:)
 827         (looking-at "!-"))))
 828
 829 (defun sign (n)
 830   "Returns -1 if N < 0, else 1."
 831   (if (>= n 0) 1 -1))
 832
 833 (defun abs (n)
 834   "Returns the absolute value of N."
 835   (if (>= n 0) n (- n)))
 836
 837 (defun next-char (direction)
 838   "Returns preceding-char if DIRECTION < 0, otherwise following-char."
 839   (if (>= direction 0) (following-char) (preceding-char)))
 840
 841 (provide 'mim-mode)
 842