lisp/mim-mode.el

   1 ;;; mim-mode.el --- Mim (MDL in MDL) mode.
   2
   3 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   4
   5 ;; Author: K. Shane Hartman
   6 ;; Maintainer: FSF
   7 ;; Keywords: languages
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 ;;; Code:
  26
  27 (autoload 'fast-syntax-check-mim "mim-syntax"
  28           "Checks Mim syntax quickly.
  29 Answers correct or incorrect, cannot point out the error context."
  30           t)
  31
  32 (autoload 'slow-syntax-check-mim "mim-syntax"
  33           "Check Mim syntax slowly.
  34 Points out the context of the error, if the syntax is incorrect."
  35           t)
  36
  37 (defvar mim-mode-hysterical-bindings t
  38   "*Non-nil means bind list manipulation commands to Meta keys as well as
  39 Control-Meta keys for historical reasons.  Otherwise, only the latter keys
  40 are bound.")
  41
  42 (defvar mim-mode-map nil)
  43
  44 (defvar mim-mode-syntax-table nil)
  45
  46 (if mim-mode-syntax-table
  47     ()
  48   (let ((i -1))
  49     (setq mim-mode-syntax-table (make-syntax-table))
  50     (while (< i ?\ )
  51       (modify-syntax-entry (setq i (1+ i)) "    " mim-mode-syntax-table))
  52     (while (< i 127)
  53       (modify-syntax-entry (setq i (1+ i)) "_   " mim-mode-syntax-table))
  54     (setq i (1- ?a))
  55     (while (< i ?z)
  56       (modify-syntax-entry (setq i (1+ i)) "w   " mim-mode-syntax-table))
  57     (setq i (1- ?A))
  58     (while (< i ?Z)
  59       (modify-syntax-entry (setq i (1+ i)) "w   " mim-mode-syntax-table))
  60     (setq i (1- ?0))
  61     (while (< i ?9)
  62       (modify-syntax-entry (setq i (1+ i)) "w   " mim-mode-syntax-table))
  63     (modify-syntax-entry ?:  "     " mim-mode-syntax-table) ; make : symbol delimiter
  64     (modify-syntax-entry ?,  "'    " mim-mode-syntax-table)
  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) ; comments are prefixed objects
  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     (modify-syntax-entry ?\[ "\(]  " mim-mode-syntax-table)
  79     (modify-syntax-entry ?\) "\)(  " mim-mode-syntax-table)
  80     (modify-syntax-entry ?\> "\)<  " mim-mode-syntax-table)
  81     (modify-syntax-entry ?\} "\){  " mim-mode-syntax-table)
  82     (modify-syntax-entry ?\] "\)[  " mim-mode-syntax-table)))
  83
  84 (defconst mim-whitespace "\000- ")
  85
  86 (defvar mim-mode-hook nil
  87   "*User function run after mim mode initialization.  Usage:
  88 \(setq mim-mode-hook '(lambda () ... your init forms ...)).")
  89
  90 (define-abbrev-table 'mim-mode-abbrev-table nil)
  91
  92 (defconst indent-mim-function 'indent-mim-function
  93   "Controls (via properties) indenting of special forms.
  94 \(put 'FOO 'indent-mim-function n\), integer n, means lines inside
  95 <FOO ...> will be indented n spaces from start of form.
  96 \(put 'FOO 'indent-mim-function 'DEFINE\) is like above but means use
  97 value of mim-body-indent as offset from start of form.
  98 \(put 'FOO 'indent-mim-function <cons>\) where <cons> is a list or pointed list
  99 of integers, means indent each form in <FOO ...> by the amount specified
 100 in <cons>.  When <cons> is exhausted, indent remaining forms by
 101 `mim-body-indent' unless <cons> is a pointed list, in which case the last
 102 cdr is used.  Confused?  Here is an example:
 103 \(put 'FROBIT 'indent-mim-function '\(4 2 . 1\)\)
 104 <FROBIT
 105      <CHOMP-IT>
 106    <CHOMP-SOME-MORE>
 107   <DIGEST>
 108   <BELCH>
 109   ...>
 110 Finally, the property can be a function name (read the code).")
 111
 112 (defvar indent-mim-comment t
 113   "*Non-nil means indent string comments.")
 114
 115 (defvar mim-body-indent 2
 116   "*Amount to indent in special forms which have DEFINE property on
 117 `indent-mim-function'.")
 118
 119 (defvar indent-mim-arglist t
 120   "*nil means indent arglists like ordinary lists.
 121 t means strings stack under start of arglist and variables stack to
 122 right of them.  Otherwise, strings stack under last string (or start
 123 of arglist if none) and variables stack to right of them.
 124 Examples (for values 'stack, t, nil):
 125
 126 \(FOO \"OPT\" BAR             \(FOO \"OPT\" BAR            \(FOO \"OPT\" BAR
 127            BAZ MUMBLE                 BAZ MUMBLE      BAZ MUMBLE
 128      \"AUX\"                  \"AUX\"                     \"AUX\"
 129      BLETCH ...             BLETCH ...                BLETCH ...")
 130
 131 (put 'DEFINE 'indent-mim-function 'DEFINE)
 132 (put 'DEFMAC 'indent-mim-function 'DEFINE)
 133 (put 'BIND 'indent-mim-function 'DEFINE)
 134 (put 'PROG 'indent-mim-function 'DEFINE)
 135 (put 'REPEAT 'indent-mim-function 'DEFINE)
 136 (put 'CASE 'indent-mim-function 'DEFINE)
 137 (put 'FUNCTION 'indent-mim-function 'DEFINE)
 138 (put 'MAPF 'indent-mim-function 'DEFINE)
 139 (put 'MAPR 'indent-mim-function 'DEFINE)
 140 (put 'UNWIND 'indent-mim-function (cons (* 2 mim-body-indent) mim-body-indent))
 141
 142 (defvar mim-down-parens-only t
 143   "*nil means treat ADECLs and ATOM trailers like structures when
 144 moving down a level of structure.")
 145
 146 (defvar mim-stop-for-slop t
 147   "*Non-nil means {next previous}-mim-object consider any
 148 non-whitespace character in column 0 to be a toplevel object, otherwise
 149 only open paren syntax characters will be considered.")
 150
 151 (defalias 'mdl-mode 'mim-mode)
 152
 153 (defun mim-mode ()
 154   "Major mode for editing Mim (MDL in MDL) code.
 155 Commands:
 156     If value of `mim-mode-hysterical-bindings' is non-nil, then following
 157 commands are assigned to escape keys as well (e.g. ESC f = ESC C-f).
 158 The default action is bind the escape keys.
 159 \\{mim-mode-map}
 160 Other Commands:
 161   Use \\[describe-function] to obtain documentation.
 162   replace-in-mim-object  find-mim-definition  fast-syntax-check-mim
 163   slow-syntax-check-mim  backward-down-mim-object  forward-up-mim-object
 164 Variables:
 165   Use \\[describe-variable] to obtain documentation.
 166   mim-mode-hook  indent-mim-comment  indent-mim-arglist  indent-mim-function
 167   mim-body-indent  mim-down-parens-only  mim-stop-for-slop
 168   mim-mode-hysterical-bindings
 169 Entry to this mode calls the value of mim-mode-hook if non-nil."
 170   (interactive)
 171   (kill-all-local-variables)
 172   (if (not mim-mode-map)
 173       (progn
 174         (setq mim-mode-map (make-sparse-keymap))
 175         (define-key mim-mode-map "\e\^o" 'open-mim-line)
 176         (define-key mim-mode-map "\e\^q" 'indent-mim-object)
 177         (define-key mim-mode-map "\e\^p" 'previous-mim-object)
 178         (define-key mim-mode-map "\e\^n" 'next-mim-object)
 179         (define-key mim-mode-map "\e\^a" 'beginning-of-DEFINE)
 180         (define-key mim-mode-map "\e\^e" 'end-of-DEFINE)
 181         (define-key mim-mode-map "\e\^t" 'transpose-mim-objects)
 182         (define-key mim-mode-map "\e\^u" 'backward-up-mim-object)
 183         (define-key mim-mode-map "\e\^d" 'forward-down-mim-object)
 184         (define-key mim-mode-map "\e\^h" 'mark-mim-object)
 185         (define-key mim-mode-map "\e\^k" 'forward-kill-mim-object)
 186         (define-key mim-mode-map "\e\^f" 'forward-mim-object)
 187         (define-key mim-mode-map "\e\^b" 'backward-mim-object)
 188         (define-key mim-mode-map "\e^" 'raise-mim-line)
 189         (define-key mim-mode-map "\e\\" 'fixup-whitespace)
 190         (define-key mim-mode-map "\177" 'backward-delete-char-untabify)
 191         (define-key mim-mode-map "\e\177" 'backward-kill-mim-object)
 192         (define-key mim-mode-map "\^j" 'newline-and-mim-indent)
 193         (define-key mim-mode-map "\e;" 'begin-mim-comment)
 194         (define-key mim-mode-map "\t" 'indent-mim-line)
 195         (define-key mim-mode-map "\e\t" 'indent-mim-object)
 196         (if (not mim-mode-hysterical-bindings)
 197             nil
 198           ;; i really hate this but too many people are accustomed to these.
 199           (define-key mim-mode-map "\e!" 'line-to-top-of-window)
 200           (define-key mim-mode-map "\eo" 'open-mim-line)
 201           (define-key mim-mode-map "\ep" 'previous-mim-object)
 202           (define-key mim-mode-map "\en" 'next-mim-object)
 203           (define-key mim-mode-map "\ea" 'beginning-of-DEFINE)
 204           (define-key mim-mode-map "\ee" 'end-of-DEFINE)
 205           (define-key mim-mode-map "\et" 'transpose-mim-objects)
 206           (define-key mim-mode-map "\eu" 'backward-up-mim-object)
 207           (define-key mim-mode-map "\ed" 'forward-down-mim-object)
 208           (define-key mim-mode-map "\ek" 'forward-kill-mim-object)
 209           (define-key mim-mode-map "\ef" 'forward-mim-object)
 210           (define-key mim-mode-map "\eb" 'backward-mim-object))))
 211   (use-local-map mim-mode-map)
 212   (set-syntax-table mim-mode-syntax-table)
 213   (make-local-variable 'paragraph-start)
 214   (setq paragraph-start (concat "$\\|" page-delimiter))
 215   (make-local-variable 'paragraph-separate)
 216   (setq paragraph-separate paragraph-start)
 217   (make-local-variable 'paragraph-ignore-fill-prefix)
 218   (setq paragraph-ignore-fill-prefix t)
 219   ;; Most people use string comments.
 220   (make-local-variable 'comment-start)
 221   (setq comment-start ";\"")
 222   (make-local-variable 'comment-start-skip)
 223   (setq comment-start-skip ";\"")
 224   (make-local-variable 'comment-end)
 225   (setq comment-end "\"")
 226   (make-local-variable 'comment-column)
 227   (setq comment-column 40)
 228   (make-local-variable 'comment-indent-function)
 229   (setq comment-indent-function 'indent-mim-comment)
 230   ;; tell generic indenter how to indent.
 231   (make-local-variable 'indent-line-function)
 232   (setq indent-line-function 'indent-mim-line)
 233   ;; look for that paren
 234   (make-local-variable 'blink-matching-paren-distance)
 235   (setq blink-matching-paren-distance nil)
 236   ;; so people who dont like tabs can turn them off locally in indenter.
 237   (make-local-variable 'indent-tabs-mode)
 238   (setq indent-tabs-mode t)
 239   (setq local-abbrev-table mim-mode-abbrev-table)
 240   (setq major-mode 'mim-mode)
 241   (setq mode-name "Mim")
 242   (run-hooks 'mim-mode-hook))
 243
 244 (defun line-to-top-of-window ()
 245   "Move current line to top of window."
 246   (interactive)                         ; for lazy people
 247   (recenter 0))
 248
 249 (defun forward-mim-object (arg)
 250   "Move forward across Mim object.
 251 With ARG, move forward that many objects."
 252   (interactive "p")
 253   ;; this function is weird because it emulates the behavior of the old
 254   ;; (gosling) mim-mode - if the arg is 1 and we are `inside' an ADECL,
 255   ;; more than one character into the ATOM part and not sitting on the
 256   ;; colon, then we move to the DECL part (just past colon) instead of
 257   ;; the end of the object (the entire ADECL).  otherwise, ADECL's are
 258   ;; atomic objects.  likewise for ATOM trailers.
 259   (if (= (abs arg) 1)
 260       (if (inside-atom-p)
 261           ;; Move to end of ATOM or to trailer (!) or to ADECL (:).
 262           (forward-sexp arg)
 263         ;; Either scan an sexp or move over one bracket.
 264         (forward-mim-objects arg t))
 265     ;; in the multi-object case, don't perform any magic.
 266     ;; treats ATOM trailers and ADECLs atomically, stops at unmatched
 267     ;; brackets with error.
 268     (forward-mim-objects arg)))
 269
 270 (defun inside-atom-p ()
 271   ;; Returns t iff inside an atom (takes account of trailers)
 272   (let ((c1 (preceding-char))
 273         (c2 (following-char)))
 274     (and (or (= (char-syntax c1) ?w) (= (char-syntax c1) ?_) (= c1 ?!))
 275          (or (= (char-syntax c2) ?w) (= (char-syntax c2) ?_) (= c2 ?!)))))
 276
 277 (defun forward-mim-objects (arg &optional skip-bracket-p)
 278   ;; Move over arg objects ignoring ADECLs and trailers.  If
 279   ;; skip-bracket-p is non-nil, then move over one bracket on error.
 280   (let ((direction (sign arg)))
 281     (condition-case conditions
 282         (while (/= arg 0)
 283           (forward-sexp direction)
 284           (if (not (inside-adecl-or-trailer-p direction))
 285               (setq arg (- arg direction))))
 286       (error (if (not skip-bracket-p)
 287                  (signal 'error (cdr conditions))
 288                (skip-mim-whitespace direction)
 289                (goto-char (+ (point) direction)))))
 290     ;; If we moved too far move back to first interesting character.
 291     (if (= (point) (buffer-end direction)) (skip-mim-whitespace (- direction)))))
 292
 293 (defun backward-mim-object (&optional arg)
 294   "Move backward across Mim object.
 295 With ARG, move backward that many objects."
 296   (interactive "p")
 297   (forward-mim-object (if arg (- arg) -1)))
 298
 299 (defun mark-mim-object (&optional arg)
 300   "Mark following Mim object.
 301 With ARG, mark that many following (preceding, ARG < 0) objects."
 302   (interactive "p")
 303   (push-mark (save-excursion (forward-mim-object (or arg 1)) (point))))
 304
 305 (defun forward-kill-mim-object (&optional arg)
 306   "Kill following Mim object.
 307 With ARG, kill that many objects."
 308   (interactive "*p")
 309   (kill-region (point) (progn (forward-mim-object (or arg 1)) (point))))
 310
 311 (defun backward-kill-mim-object (&optional arg)
 312   "Kill preceding Mim object.
 313 With ARG, kill that many objects."
 314   (interactive "*p")
 315   (forward-kill-mim-object (- (or arg 1))))
 316
 317 (defun raise-mim-line (&optional arg)
 318   "Raise following line, fixing up whitespace at join.
 319 With ARG raise that many following lines.
 320 A negative ARG will raise current line and previous lines."
 321   (interactive "*p")
 322   (let* ((increment (sign (or arg (setq arg 1))))
 323          (direction (if (> arg 0) 1 0)))
 324     (save-excursion
 325       (while (/= arg 0)
 326         ;; move over eol and kill it
 327         (forward-line direction)
 328         (delete-region (point) (1- (point)))
 329         (fixup-whitespace)
 330         (setq arg (- arg increment))))))
 331
 332 (defun forward-down-mim-object (&optional arg)
 333   "Move down a level of Mim structure forwards.
 334 With ARG, move down that many levels forwards (backwards, ARG < 0)."
 335   (interactive "p")
 336   ;; another weirdo - going down `inside' an ADECL or ATOM trailer
 337   ;; depends on the value of mim-down-parens-only.  if nil, treat
 338   ;; ADECLs and trailers as structured objects.
 339   (let ((direction (sign (or arg (setq arg 1)))))
 340     (if (and (= (abs arg) 1) (not mim-down-parens-only))
 341         (goto-char
 342           (save-excursion
 343             (skip-mim-whitespace direction)
 344             (if (> direction 0) (re-search-forward "\\s'*"))
 345             (or (and (let ((c (next-char direction)))
 346                        (or (= (char-syntax c) ?_)
 347                            (= (char-syntax c) ?w)))
 348                      (progn (forward-sexp direction)
 349                             (if (inside-adecl-or-trailer-p direction)
 350                                 (point))))
 351                 (scan-lists (point) direction -1)
 352                 (buffer-end direction))))
 353       (while (/= arg 0)
 354         (goto-char (or (scan-lists (point) direction -1) (buffer-end direction)))
 355         (setq arg (- arg direction))))))
 356
 357 (defun backward-down-mim-object (&optional arg)
 358   "Move down a level of Mim structure backwards.
 359 With ARG, move down that many levels backwards (forwards, ARG < 0)."
 360   (interactive "p")
 361   (forward-down-mim-object (if arg (- arg) -1)))
 362
 363 (defun forward-up-mim-object (&optional arg)
 364   "Move up a level of Mim structure forwards
 365 With ARG, move up that many levels forwards (backwards, ARG < 0)."
 366   (interactive "p")
 367   (let ((direction (sign (or arg (setq arg 1)))))
 368     (while (/= arg 0)
 369       (goto-char (or (scan-lists (point) direction 1) (buffer-end arg)))
 370       (setq arg (- arg direction)))
 371     (if (< direction 0) (backward-prefix-chars))))
 372
 373 (defun backward-up-mim-object (&optional arg)
 374   "Move up a level of Mim structure backwards
 375 With ARG, move up that many levels backwards (forwards, ARG > 0)."
 376   (interactive "p")
 377   (forward-up-mim-object (if arg (- arg) -1)))
 378
 379 (defun replace-in-mim-object (old new)
 380   "Replace string in following Mim object."
 381   (interactive "*sReplace in object: \nsReplace %s with: ")
 382   (save-restriction
 383     (narrow-to-region (point) (save-excursion (forward-mim-object 1) (point)))
 384     (replace-string old new)))
 385
 386 (defun transpose-mim-objects (&optional arg)
 387   "Transpose Mim objects around point.
 388 With ARG, transpose preceding object that many times with following objects.
 389 A negative ARG will transpose backwards."
 390   (interactive "*p")
 391   (transpose-subr 'forward-mim-object (or arg 1)))
 392
 393 (defun beginning-of-DEFINE (&optional arg move)
 394   "Move backward to beginning of surrounding or previous toplevel Mim form.
 395 With ARG, do it that many times.  Stops at last toplevel form seen if buffer
 396 end is reached."
 397   (interactive "p")
 398   (let ((direction (sign (or arg (setq arg 1)))))
 399     (if (not move) (setq move t))
 400     (if (< direction 0) (goto-char (1+ (point))))
 401     (while (and (/= arg 0) (re-search-backward "^<" nil move direction))
 402       (setq arg (- arg direction)))
 403     (if (< direction 0)
 404         (goto-char (1- (point))))))
 405
 406 (defun end-of-DEFINE (&optional arg)
 407   "Move forward to end of surrounding or next toplevel mim form.
 408 With ARG, do it that many times.  Stops at end of last toplevel form seen
 409 if buffer end is reached."
 410   (interactive "p")
 411   (if (not arg) (setq arg 1))
 412   (if (< arg 0)
 413       (beginning-of-DEFINE (- (1- arg)))
 414     (if (not (looking-at "^<")) (setq arg (1+ arg)))
 415     (beginning-of-DEFINE (- arg) 'move)
 416     (beginning-of-DEFINE 1))
 417   (forward-mim-object 1)
 418   (forward-line 1))
 419
 420 (defun next-mim-object (&optional arg)
 421   "Move to beginning of next toplevel Mim object.
 422 With ARG, do it that many times.  Stops at last object seen if buffer end
 423 is reached."
 424   (interactive "p")
 425   (let ((search-string (if mim-stop-for-slop "^\\S " "^\\s("))
 426         (direction (sign (or arg (setq arg 1)))))
 427     (if (> direction 0)
 428         (goto-char (1+ (point))))               ; no error if end of buffer
 429     (while (and (/= arg 0)
 430                 (re-search-forward search-string nil t direction))
 431       (setq arg (- arg direction)))
 432     (if (> direction 0)
 433         (goto-char (1- (point))))               ; no error if beginning of buffer
 434     ;; scroll to top of window if moving forward and end not visible.
 435     (if (not (or (< direction 0)
 436                  (save-excursion (forward-mim-object 1)
 437                                  (pos-visible-in-window-p (point)))))
 438         (recenter 0))))
 439
 440 (defun previous-mim-object (&optional arg)
 441   "Move to beginning of previous toplevel Mim object.
 442 With ARG do it that many times.  Stops at last object seen if buffer end
 443 is reached."
 444   (interactive "p")
 445   (next-mim-object (- (or arg 1))))
 446
 447 (defun calculate-mim-indent (&optional parse-start)
 448   "Calculate indentation for Mim line.  Returns column."
 449   (save-excursion                       ; some excursion, huh, toto?
 450     (beginning-of-line)
 451     (let ((indent-point (point)) retry state containing-sexp last-sexp
 452           desired-indent start peek where paren-depth)
 453       (if parse-start
 454           (goto-char parse-start)       ; should be containing environment
 455         (catch 'from-the-top
 456           ;; find a place to start parsing.  going backwards is fastest.
 457           ;; forward-sexp signals error on encountering unmatched open.
 458           (setq retry t)
 459           (while retry
 460             (condition-case nil (forward-sexp -1) (error (setq retry nil)))
 461             (if (looking-at ".?[ \t]*\"")
 462                 ;; cant parse backward in presence of strings, go forward.
 463                 (progn
 464                   (goto-char indent-point)
 465                   (re-search-backward "^\\s(" nil 'move 1)  ; to top of object
 466                   (throw 'from-the-top nil)))
 467             (setq retry (and retry (/= (current-column) 0))))
 468           (skip-chars-backward mim-whitespace)
 469           (if (not (bobp)) (forward-char -1))     ; onto unclosed open
 470           (backward-prefix-chars)))
 471       ;; find outermost containing sexp if we started inside an sexp.
 472       (while (< (point) indent-point)
 473         (setq state (parse-partial-sexp (point) indent-point 0)))
 474       ;; find usual column to indent under (not in string or toplevel).
 475       ;; on termination, state will correspond to containing environment
 476       ;; (if retry is nil), where will be position of character to indent
 477       ;; under normally, and desired-indent will be the column to indent to
 478       ;; except if inside form, string, or at toplevel.  point will be in
 479       ;; in column to indent to unless inside string.
 480       (setq retry t)
 481       (while (and retry (setq paren-depth (car state)) (> paren-depth 0))
 482         ;; find innermost containing sexp.
 483         (setq retry nil)
 484         (setq last-sexp (car (nthcdr 2 state)))
 485         (setq containing-sexp (car (cdr state)))
 486         (goto-char (1+ containing-sexp))          ; to last unclosed open
 487         (if (and last-sexp (> last-sexp (point)))
 488             ;; is the last sexp a containing sexp?
 489             (progn (setq peek (parse-partial-sexp last-sexp indent-point 0))
 490                    (if (setq retry (car (cdr peek))) (setq state peek))))
 491         (if retry
 492             nil
 493           (setq where (1+ containing-sexp))   ; innermost containing sexp
 494           (goto-char where)
 495           (cond
 496            ((not last-sexp)                   ; indent-point after bracket
 497             (setq desired-indent (current-column)))
 498            ((= (preceding-char) ?\<)          ; it's a form
 499             (cond ((> (progn (forward-sexp 1) (point)) last-sexp)
 500                    (goto-char where))         ; only one frob
 501                   ((> (save-excursion (forward-line 1) (point)) last-sexp)
 502                    (skip-chars-forward " \t") ; last-sexp is on same line
 503                    (setq where (point)))              ; as containing-sexp
 504                   ((progn
 505                      (goto-char last-sexp)
 506                      (beginning-of-line)
 507                      (parse-partial-sexp (point) last-sexp 0 t)
 508                      (or (= (point) last-sexp)
 509                          (save-excursion
 510                            (= (car (parse-partial-sexp (point) last-sexp 0))
 511                               0))))
 512                    (backward-prefix-chars)    ; last-sexp 1st on line or 1st
 513                    (setq where (point)))        ; frob on that line level 0
 514                   (t (goto-char where))))     ; punt, should never occur
 515            ((and indent-mim-arglist           ; maybe hack arglist
 516                  (= (preceding-char) ?\()     ; its a list
 517                  (save-excursion              ; look for magic atoms
 518                    (setq peek 0)              ; using peek as counter
 519                    (forward-char -1)          ; back over containing paren
 520                    (while (and (< (setq peek (1+ peek)) 6)
 521                                (condition-case nil
 522                                    (progn (forward-sexp -1) t)
 523                                  (error nil))))
 524                    (and (< peek 6) (looking-at "DEFINE\\|DEFMAC\\|FUNCTION"))))
 525             ;; frobs stack under strings they belong to or under first
 526             ;; frob to right of strings they belong to unless luser has
 527             ;; frob (non-string) on preceding line with different
 528             ;; indentation.  strings stack under start of arglist unless
 529             ;; mim-indent-arglist is not t, in which case they stack
 530             ;; under the last string, if any, else the start of the arglist.
 531             (let ((eol 0) last-string)
 532               (while (< (point) last-sexp)      ; find out where the strings are
 533                 (skip-chars-forward mim-whitespace last-sexp)
 534                 (if (> (setq start (point)) eol)
 535                     (progn                    ; simultaneously keeping track
 536                       (setq where (min where start))
 537                       (end-of-line)           ; of indentation of first frob
 538                       (setq eol (point))              ; on each line
 539                       (goto-char start)))
 540                 (if (= (following-char) ?\")
 541                     (progn (setq last-string (point))
 542                            (forward-sexp 1)
 543                            (if (= last-string last-sexp)
 544                                (setq where last-sexp)
 545                              (skip-chars-forward mim-whitespace last-sexp)
 546                              (setq where (point))))
 547                   (forward-sexp 1)))
 548               (goto-char indent-point)             ; if string is first on
 549               (skip-chars-forward " \t" (point-max)) ; line we are indenting, it
 550               (if (= (following-char) ?\")         ; goes under arglist start
 551                   (if (and last-string (not (equal indent-mim-arglist t)))
 552                       (setq where last-string)     ; or under last string.
 553                     (setq where (1+ containing-sexp)))))
 554             (goto-char where)
 555             (setq desired-indent (current-column)))
 556            (t                                 ; plain vanilla structure
 557             (cond ((> (save-excursion (forward-line 1) (point)) last-sexp)
 558                    (skip-chars-forward " \t") ; last-sexp is on same line
 559                    (setq where (point)))              ; as containing-sexp
 560                   ((progn
 561                      (goto-char last-sexp)
 562                      (beginning-of-line)
 563                      (parse-partial-sexp (point) last-sexp 0 t)
 564                      (or (= (point) last-sexp)
 565                          (save-excursion
 566                            (= (car (parse-partial-sexp (point) last-sexp 0))
 567                               0))))
 568                      (backward-prefix-chars)  ; last-sexp 1st on line or 1st
 569                      (setq where (point)))      ; frob on that line level 0
 570                   (t (goto-char where)))      ; punt, should never occur
 571             (setq desired-indent (current-column))))))
 572       ;; state is innermost containing environment unless toplevel or string.
 573       (if (car (nthcdr 3 state))              ; inside string
 574           (progn
 575             (if last-sexp                     ; string must be next
 576                 (progn (goto-char last-sexp)
 577                        (forward-sexp 1)
 578                        (search-forward "\"")
 579                        (forward-char -1))
 580               (goto-char indent-point)        ; toplevel string, look for it
 581               (re-search-backward "[^\\]\"")
 582               (forward-char 1))
 583             (setq start (point))                      ; opening double quote
 584             (skip-chars-backward " \t")
 585             (backward-prefix-chars)
 586             ;; see if the string is really a comment.
 587             (if (and (looking-at ";[ \t]*\"") indent-mim-comment)
 588                 ;; it's a comment, line up under the start unless disabled.
 589                 (goto-char (1+ start))
 590               ;; it's a string, dont mung the indentation.
 591               (goto-char indent-point)
 592               (skip-chars-forward " \t"))
 593             (setq desired-indent (current-column))))
 594       ;; point is sitting in usual column to indent to and if retry is nil
 595       ;; then state corresponds to containing environment.  if desired
 596       ;; indentation not determined, we are inside a form, so call hook.
 597       (or desired-indent
 598           (and indent-mim-function
 599                (not retry)
 600                (setq desired-indent
 601                      (funcall indent-mim-function state indent-point)))
 602           (setq desired-indent (current-column)))
 603       (goto-char indent-point)          ; back to where we started
 604       desired-indent)))                 ; return column to indent to
 605
 606 (defun indent-mim-function (state indent-point)
 607   "Compute indentation for Mim special forms.  Returns column or nil."
 608   (let ((containing-sexp (car (cdr state))) (current-indent (point)))
 609     (save-excursion
 610       (goto-char (1+ containing-sexp))
 611       (backward-prefix-chars)
 612       ;; make sure we are looking at a symbol.  if so, see if it is a special
 613       ;; symbol.  if so, add the special indentation to the indentation of
 614       ;; the start of the special symbol, unless the property is not
 615       ;; an integer and not nil (in this case, call the property, it must
 616       ;; be a function which returns the appropriate indentation or nil and
 617       ;; does not change the buffer).
 618       (if (looking-at "\\sw\\|\\s_")
 619           (let* ((start (current-column))
 620                  (function
 621                   (intern-soft (buffer-substring (point)
 622                                                  (progn (forward-sexp 1)
 623                                                         (point)))))
 624                  (method (get function 'indent-mim-function)))
 625             (if (or (if (equal method 'DEFINE) (setq method mim-body-indent))
 626                     (integerp method))
 627                 ;; only use method if its first line after containing-sexp.
 628                 ;; we could have done this in calculate-mim-indent, but someday
 629                 ;; someone might want to format frobs in a special form based
 630                 ;; on position instead of indenting uniformly (like lisp if),
 631                 ;; so preserve right for posterity.  if not first line,
 632                 ;; calculate-mim-indent already knows right indentation -
 633                 ;; give luser chance to change indentation manually by changing
 634                 ;; 1st line after containing-sexp.
 635                 (if (> (progn (forward-line 1) (point)) (car (nthcdr 2 state)))
 636                     (+ method start))
 637               (goto-char current-indent)
 638               (if (consp method)
 639                   ;; list or pointed list of explicit indentations
 640                   (indent-mim-offset state indent-point)
 641                 (if (and (symbolp method) (fboundp method))
 642                     ;; luser function - s/he better know what's going on.
 643                     ;; should take state and indent-point as arguments - for
 644                     ;; description of state, see parse-partial-sexp
 645                     ;; documentation the function is guaranteed the following:
 646                     ;; (1) state describes the closest surrounding form,
 647                     ;; (2) indent-point is the beginning of the line being
 648                     ;; indented, (3) point points to char in column that would
 649                     ;; normally be used for indentation, (4) function is bound
 650                     ;; to the special ATOM.  See indent-mim-offset for example
 651                     ;; of a special function.
 652                     (funcall method state indent-point)))))))))
 653
 654 (defun indent-mim-offset (state indent-point)
 655   ;; offset forms explicitly according to list of indentations.
 656   (let ((mim-body-indent mim-body-indent)
 657         (indentations (get function 'indent-mim-function))
 658         (containing-sexp (car (cdr state)))
 659         (last-sexp (car (nthcdr 2 state)))
 660         indentation)
 661     (goto-char (1+ containing-sexp))
 662     ;; determine which of the indentations to use.
 663     (while (and (< (point) indent-point)
 664                 (condition-case nil
 665                     (progn (forward-sexp 1)
 666                            (parse-partial-sexp (point) indent-point 1 t))
 667                   (error nil)))
 668       (skip-chars-backward " \t")
 669       (backward-prefix-chars)
 670       (if (= (following-char) ?\;)
 671           nil                                       ; ignore comments
 672         (setq indentation (car indentations))
 673         (if (integerp (setq indentations (cdr indentations)))
 674             ;; if last cdr is integer, that is indentation to use for all
 675             ;; all the rest of the forms.
 676             (progn (setq mim-body-indent indentations)
 677                    (setq indentations nil)))))
 678     (goto-char (1+ containing-sexp))
 679     (+ (current-column) (or indentation mim-body-indent))))
 680
 681 (defun indent-mim-comment (&optional start)
 682   "Indent a one line (string) Mim comment following object, if any."
 683   (let* ((old-point (point)) (eol (progn (end-of-line) (point))) state last-sexp)
 684     ;; this function assumes that comment indenting is enabled.  it is caller's
 685     ;; responsibility to check the indent-mim-comment flag before calling.
 686     (beginning-of-line)
 687     (catch 'no-comment
 688       (setq state (parse-partial-sexp (point) eol))
 689       ;; determine if there is an existing regular comment.  a `regular'
 690       ;; comment is defined as a commented string which is the last thing
 691       ;; on the line and does not extend beyond the end of the line.
 692       (if (or (not (setq last-sexp (car (nthcdr 2 state))))
 693               (car (nthcdr 3 state)))
 694           ;; empty line or inside string (multiple line).
 695           (throw 'no-comment nil))
 696       ;; could be a comment, but make sure its not the only object.
 697       (beginning-of-line)
 698       (parse-partial-sexp (point) eol 0 t)
 699       (if (= (point) last-sexp)
 700           ;; only one object on line
 701           (throw 'no-comment t))
 702       (goto-char last-sexp)
 703       (skip-chars-backward " \t")
 704       (backward-prefix-chars)
 705       (if (not (looking-at ";[ \t]*\""))
 706           ;; aint no comment
 707           (throw 'no-comment nil))
 708       ;; there is an existing regular comment
 709       (delete-horizontal-space)
 710       ;; move it to comment-column if possible else to tab-stop
 711       (if (< (current-column) comment-column)
 712           (indent-to comment-column)
 713         (tab-to-tab-stop)))
 714     (goto-char old-point)))
 715
 716 (defun indent-mim-line ()
 717   "Indent line of Mim code."
 718   (interactive "*")
 719   (let* ((position (- (point-max) (point)))
 720          (bol (progn (beginning-of-line) (point)))
 721          (indent (calculate-mim-indent)))
 722     (skip-chars-forward " \t")
 723     (if (/= (current-column) indent)
 724         (progn (delete-region bol (point)) (indent-to indent)))
 725     (if (> (- (point-max) position) (point)) (goto-char (- (point-max) position)))))
 726
 727 (defun newline-and-mim-indent ()
 728   "Insert newline at point and indent."
 729   (interactive "*")
 730   ;; commented code would correct indentation of line in arglist which
 731   ;; starts with string, but it would indent every line twice.  luser can
 732   ;; just say tab after typing string to get same effect.
 733   ;(if indent-mim-arglist (indent-mim-line))
 734   (newline)
 735   (indent-mim-line))
 736
 737 (defun open-mim-line (&optional lines)
 738   "Insert newline before point and indent.
 739 With ARG insert that many newlines."
 740   (interactive "*p")
 741   (beginning-of-line)
 742   (let ((indent (calculate-mim-indent)))
 743     (while (> lines 0)
 744       (newline)
 745       (forward-line -1)
 746       (indent-to indent)
 747       (setq lines (1- lines)))))
 748
 749 (defun indent-mim-object (&optional dont-indent-first-line)
 750   "Indent object following point and all lines contained inside it.
 751 With ARG, idents only contained lines (skips first line)."
 752   (interactive "*P")
 753   (let (end bol indent start)
 754     (save-excursion (parse-partial-sexp (point) (point-max) 0 t)
 755                     (setq start (point))
 756                     (forward-sexp 1)
 757                     (setq end (- (point-max) (point))))
 758     (save-excursion
 759       (if (not dont-indent-first-line) (indent-mim-line))
 760       (while (progn (forward-line 1) (> (- (point-max) (point)) end))
 761         (setq indent (calculate-mim-indent start))
 762         (setq bol (point))
 763         (skip-chars-forward " \t")
 764         (if (/= indent (current-column))
 765             (progn (delete-region bol (point)) (indent-to indent)))
 766         (if indent-mim-comment (indent-mim-comment))))))
 767
 768 (defun find-mim-definition (name)
 769   "Search for definition of function, macro, or gfcn.
 770 You need type only enough of the name to be unambiguous."
 771   (interactive "sName: ")
 772   (let (where)
 773     (save-excursion
 774       (goto-char (point-min))
 775       (condition-case nil
 776           (progn
 777             (re-search-forward
 778              (concat "^<\\(DEFINE\\|\\DEFMAC\\|FCN\\|GFCN\\)\\([ \t]*\\)"
 779                      name))
 780             (setq where (point)))
 781         (error (error "Can't find %s" name))))
 782     (if where
 783         (progn (push-mark)
 784                (goto-char where)
 785                (beginning-of-line)
 786                (recenter 0)))))
 787
 788 (defun begin-mim-comment ()
 789   "Move to existing comment or insert empty comment."
 790   (interactive "*")
 791   (let* ((eol (progn (end-of-line) (point)))
 792          (bol (progn (beginning-of-line) (point))))
 793     ;; check for existing comment first.
 794     (if (re-search-forward ";[ \t]*\"" eol t)
 795         ;; found it.  indent if desired and go there.
 796         (if indent-mim-comment
 797             (let ((where (- (point-max) (point))))
 798               (indent-mim-comment)
 799               (goto-char (- (point-max) where))))
 800       ;; nothing there, make a comment.
 801       (let (state last-sexp)
 802         ;; skip past all the sexps on the line
 803         (goto-char bol)
 804         (while (and (equal (car (setq state (parse-partial-sexp (point) eol 0)))
 805                            0)
 806                     (car (nthcdr 2 state)))
 807           (setq last-sexp (car (nthcdr 2 state))))
 808         (if (car (nthcdr 3 state))
 809             nil                                     ; inside a string, punt
 810       (delete-region (point) eol)                           ; flush trailing whitespace
 811       (if (and (not last-sexp) (equal (car state) 0))
 812           (indent-to (calculate-mim-indent))        ; empty, indent like code
 813         (if (> (current-column) comment-column)     ; indent to comment column
 814             (tab-to-tab-stop)                       ; unless past it, else to
 815           (indent-to comment-column)))              ; tab-stop
 816       ;; if luser changes comment-{start end} to something besides semi
 817       ;; followed by zero or more whitespace characters followed by string
 818       ;; delimiters, the code above fails to find existing comments, but as
 819       ;; taa says, `let the losers lose'.
 820       (insert comment-start)
 821       (save-excursion (insert comment-end)))))))
 822
 823 (defun skip-mim-whitespace (direction)
 824   (if (>= direction 0)
 825       (skip-chars-forward mim-whitespace (point-max))
 826     (skip-chars-backward mim-whitespace (point-min))))
 827
 828 (defun inside-adecl-or-trailer-p (direction)
 829   (if (>= direction 0)
 830       (looking-at ":\\|!-")
 831     (or (= (preceding-char) ?:)
 832         (looking-at "!-"))))
 833
 834 (defun sign (n)
 835   "Returns -1 if N < 0, else 1."
 836   (if (>= n 0) 1 -1))
 837
 838 (defun abs (n)
 839   "Returns the absolute value of N."
 840   (if (>= n 0) n (- n)))
 841
 842 (defun next-char (direction)
 843   "Returns preceding-char if DIRECTION < 0, otherwise following-char."
 844   (if (>= direction 0) (following-char) (preceding-char)))
 845
 846 (provide 'mim-mode)
 847
 848 ;;; mim-mode.el ends here