lisp/progmodes/icon.el

   1 ;;; icon.el --- mode for editing Icon code
   2
   3 ;; Copyright (C) 1989 Free Software Foundation, Inc.
   4
   5 ;; Author: Chris Smith <csmith@convex.com>
   6 ;; Created: 15 Feb 89
   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 the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; A major mode for editing the Icon programming language.
  29
  30 ;;; Code:
  31
  32 (defvar icon-mode-abbrev-table nil
  33   "Abbrev table in use in Icon-mode buffers.")
  34 (define-abbrev-table 'icon-mode-abbrev-table ())
  35
  36 (defvar icon-mode-map ()
  37   "Keymap used in Icon mode.")
  38 (if icon-mode-map
  39     ()
  40   (let ((map (make-sparse-keymap "Icon")))
  41     (setq icon-mode-map (make-sparse-keymap))
  42     (define-key icon-mode-map "{" 'electric-icon-brace)
  43     (define-key icon-mode-map "}" 'electric-icon-brace)
  44     (define-key icon-mode-map "\e\C-h" 'mark-icon-function)
  45     (define-key icon-mode-map "\e\C-a" 'beginning-of-icon-defun)
  46     (define-key icon-mode-map "\e\C-e" 'end-of-icon-defun)
  47     (define-key icon-mode-map "\e\C-q" 'indent-icon-exp)
  48     (define-key icon-mode-map "\177" 'backward-delete-char-untabify)
  49
  50     (define-key icon-mode-map [menu-bar] (make-sparse-keymap "Icon"))
  51     (define-key icon-mode-map [menu-bar icon]
  52       (cons "Icon" map))
  53     (define-key map [beginning-of-icon-defun] '("Beginning of function" . beginning-of-icon-defun))
  54     (define-key map [end-of-icon-defun] '("End of function" . end-of-icon-defun))
  55     (define-key map [comment-region] '("Comment Out Region" . comment-region))
  56     (define-key map [indent-region] '("Indent Region" . indent-region))
  57     (define-key map [indent-line] '("Indent Line" . icon-indent-command))
  58     (put 'eval-region 'menu-enable 'mark-active)
  59     (put 'comment-region 'menu-enable 'mark-active)
  60     (put 'indent-region 'menu-enable 'mark-active)))
  61
  62 (defvar icon-mode-syntax-table nil
  63   "Syntax table in use in Icon-mode buffers.")
  64
  65 (if icon-mode-syntax-table
  66     ()
  67   (setq icon-mode-syntax-table (make-syntax-table))
  68   (modify-syntax-entry ?\\ "\\" icon-mode-syntax-table)
  69   (modify-syntax-entry ?# "<" icon-mode-syntax-table)
  70   (modify-syntax-entry ?\n ">" icon-mode-syntax-table)
  71   (modify-syntax-entry ?$ "." icon-mode-syntax-table)
  72   (modify-syntax-entry ?/ "." icon-mode-syntax-table)
  73   (modify-syntax-entry ?* "." icon-mode-syntax-table)
  74   (modify-syntax-entry ?+ "." icon-mode-syntax-table)
  75   (modify-syntax-entry ?- "." icon-mode-syntax-table)
  76   (modify-syntax-entry ?= "." icon-mode-syntax-table)
  77   (modify-syntax-entry ?% "." icon-mode-syntax-table)
  78   (modify-syntax-entry ?< "." icon-mode-syntax-table)
  79   (modify-syntax-entry ?> "." icon-mode-syntax-table)
  80   (modify-syntax-entry ?& "." icon-mode-syntax-table)
  81   (modify-syntax-entry ?| "." icon-mode-syntax-table)
  82   (modify-syntax-entry ?\' "\"" icon-mode-syntax-table))
  83
  84 (defgroup icon nil
  85   "Mode for editing Icon code."
  86   :group 'languages)
  87
  88 (defcustom icon-indent-level 4
  89   "*Indentation of Icon statements with respect to containing block."
  90   :type 'integer
  91   :group 'icon)
  92
  93 (defcustom icon-brace-imaginary-offset 0
  94   "*Imagined indentation of a Icon open brace that actually follows a statement."
  95   :type 'integer
  96   :group 'icon)
  97
  98 (defcustom icon-brace-offset 0
  99   "*Extra indentation for braces, compared with other text in same context."
 100   :type 'integer
 101   :group 'icon)
 102
 103 (defcustom icon-continued-statement-offset 4
 104   "*Extra indent for Icon lines not starting new statements."
 105   :type 'integer
 106   :group 'icon)
 107
 108 (defcustom icon-continued-brace-offset 0
 109   "*Extra indent for Icon substatements that start with open-braces.
 110 This is in addition to `icon-continued-statement-offset'."
 111   :type 'integer
 112   :group 'icon)
 113
 114 (defcustom icon-auto-newline nil
 115   "*Non-nil means automatically newline before and after braces Icon code.
 116 This applies when braces are inserted."
 117   :type 'boolean
 118   :group 'icon)
 119
 120 (defcustom icon-tab-always-indent t
 121   "*Non-nil means TAB in Icon mode should always reindent the current line.
 122 It will then reindent, regardless of where in the line point is
 123 when the TAB command is used."
 124   :type 'boolean
 125   :group 'icon)
 126
 127 (defvar icon-imenu-generic-expression
 128       '((nil "^[ \t]*procedure[ \t]+\\(\\sw+\\)[ \t]*("  1))
 129   "Imenu expression for Icon mode.  See `imenu-generic-expression'.")
 130
 131
 132 \f
 133 ;;;###autoload
 134 (defun icon-mode ()
 135   "Major mode for editing Icon code.
 136 Expression and list commands understand all Icon brackets.
 137 Tab indents for Icon code.
 138 Paragraphs are separated by blank lines only.
 139 Delete converts tabs to spaces as it moves back.
 140 \\{icon-mode-map}
 141 Variables controlling indentation style:
 142  icon-tab-always-indent
 143     Non-nil means TAB in Icon mode should always reindent the current line,
 144     regardless of where in the line point is when the TAB command is used.
 145  icon-auto-newline
 146     Non-nil means automatically newline before and after braces
 147     inserted in Icon code.
 148  icon-indent-level
 149     Indentation of Icon statements within surrounding block.
 150     The surrounding block's indentation is the indentation
 151     of the line on which the open-brace appears.
 152  icon-continued-statement-offset
 153     Extra indentation given to a substatement, such as the
 154     then-clause of an if or body of a while.
 155  icon-continued-brace-offset
 156     Extra indentation given to a brace that starts a substatement.
 157     This is in addition to `icon-continued-statement-offset'.
 158  icon-brace-offset
 159     Extra indentation for line if it starts with an open brace.
 160  icon-brace-imaginary-offset
 161     An open brace following other text is treated as if it were
 162     this far to the right of the start of its line.
 163
 164 Turning on Icon mode calls the value of the variable `icon-mode-hook'
 165 with no args, if that value is non-nil."
 166   (interactive)
 167   (kill-all-local-variables)
 168   (use-local-map icon-mode-map)
 169   (setq major-mode 'icon-mode)
 170   (setq mode-name "Icon")
 171   (setq local-abbrev-table icon-mode-abbrev-table)
 172   (set-syntax-table icon-mode-syntax-table)
 173   (make-local-variable 'paragraph-start)
 174   (setq paragraph-start (concat "$\\|" page-delimiter))
 175   (make-local-variable 'paragraph-separate)
 176   (setq paragraph-separate paragraph-start)
 177   (make-local-variable 'indent-line-function)
 178   (setq indent-line-function 'icon-indent-line)
 179   (make-local-variable 'require-final-newline)
 180   (setq require-final-newline t)
 181   (make-local-variable 'comment-start)
 182   (setq comment-start "# ")
 183   (make-local-variable 'comment-end)
 184   (setq comment-end "")
 185   (make-local-variable 'comment-start-skip)
 186   (setq comment-start-skip "# *")
 187   (make-local-variable 'comment-indent-function)
 188   (setq comment-indent-function 'icon-comment-indent)
 189   (set (make-local-variable 'indent-line-function) 'icon-indent-line)
 190   ;; font-lock support
 191   (setq font-lock-defaults
 192         '((icon-font-lock-keywords
 193            icon-font-lock-keywords-1 icon-font-lock-keywords-2)
 194           nil nil ((?_ . "w")) beginning-of-defun
 195           ;; Obsoleted by Emacs 19.35 parse-partial-sexp's COMMENTSTOP.
 196           ;(font-lock-comment-start-regexp . "#")
 197           (font-lock-mark-block-function . mark-defun)))
 198   ;; imenu support
 199   (make-local-variable 'imenu-generic-expression)
 200   (setq imenu-generic-expression icon-imenu-generic-expression)
 201   ;; hideshow support
 202   ;; we start from the assertion that `hs-special-modes-alist' is autoloaded.
 203   (unless (assq 'icon-mode hs-special-modes-alist)
 204     (setq hs-special-modes-alist
 205           (cons '(icon-mode  "\\<procedure\\>" "\\<end\\>" nil
 206                              icon-forward-sexp-function)
 207                 hs-special-modes-alist)))
 208   (run-hooks 'icon-mode-hook))
 209 \f
 210 ;; This is used by indent-for-comment to decide how much to
 211 ;; indent a comment in Icon code based on its context.
 212 (defun icon-comment-indent ()
 213   (if (looking-at "^#") 0 comment-column))
 214
 215 (defun electric-icon-brace (arg)
 216   "Insert character and correct line's indentation."
 217   (interactive "P")
 218   (let (insertpos)
 219     (if (and (not arg)
 220              (eolp)
 221              (or (save-excursion
 222                    (skip-chars-backward " \t")
 223                    (bolp))
 224                  (if icon-auto-newline
 225                      (progn (icon-indent-line) (newline) t)
 226                    nil)))
 227         (progn
 228           (insert last-command-char)
 229           (icon-indent-line)
 230           (if icon-auto-newline
 231               (progn
 232                 (newline)
 233                 ;; (newline) may have done auto-fill
 234                 (setq insertpos (- (point) 2))
 235                 (icon-indent-line)))
 236           (save-excursion
 237             (if insertpos (goto-char (1+ insertpos)))
 238             (delete-char -1))))
 239     (if insertpos
 240         (save-excursion
 241           (goto-char insertpos)
 242           (self-insert-command (prefix-numeric-value arg)))
 243       (self-insert-command (prefix-numeric-value arg)))))
 244 \f
 245 (defun icon-indent-command (&optional whole-exp)
 246   "Indent current line as Icon code, or in some cases insert a tab character.
 247 If `icon-tab-always-indent' is non-nil (the default), always indent current
 248 line.  Otherwise, indent the current line only if point is at the left margin
 249 or in the line's indentation; otherwise insert a tab.
 250
 251 A numeric argument, regardless of its value, means indent rigidly all the
 252 lines of the expression starting after point so that this line becomes
 253 properly indented.  The relative indentation among the lines of the
 254 expression are preserved."
 255   (interactive "P")
 256   (if whole-exp
 257       ;; If arg, always indent this line as Icon
 258       ;; and shift remaining lines of expression the same amount.
 259       (let ((shift-amt (icon-indent-line))
 260             beg end)
 261         (save-excursion
 262           (if icon-tab-always-indent
 263               (beginning-of-line))
 264           (setq beg (point))
 265           (forward-sexp 1)
 266           (setq end (point))
 267           (goto-char beg)
 268           (forward-line 1)
 269           (setq beg (point)))
 270         (if (> end beg)
 271             (indent-code-rigidly beg end shift-amt "#")))
 272     (if (and (not icon-tab-always-indent)
 273              (save-excursion
 274                (skip-chars-backward " \t")
 275                (not (bolp))))
 276         (insert-tab)
 277       (icon-indent-line))))
 278
 279 (defun icon-indent-line ()
 280   "Indent current line as Icon code.
 281 Return the amount the indentation changed by."
 282   (let ((indent (calculate-icon-indent nil))
 283         beg shift-amt
 284         (case-fold-search nil)
 285         (pos (- (point-max) (point))))
 286     (beginning-of-line)
 287     (setq beg (point))
 288     (cond ((eq indent nil)
 289            (setq indent (current-indentation)))
 290           ((looking-at "^#")
 291            (setq indent 0))
 292           (t
 293            (skip-chars-forward " \t")
 294            (if (listp indent) (setq indent (car indent)))
 295            (cond ((and (looking-at "else\\b")
 296                        (not (looking-at "else\\s_")))
 297                   (setq indent (save-excursion
 298                                  (icon-backward-to-start-of-if)
 299                                  (current-indentation))))
 300                  ((or (= (following-char) ?})
 301                       (looking-at "end\\b"))
 302                   (setq indent (- indent icon-indent-level)))
 303                  ((= (following-char) ?{)
 304                   (setq indent (+ indent icon-brace-offset))))))
 305     (skip-chars-forward " \t")
 306     (setq shift-amt (- indent (current-column)))
 307     (if (zerop shift-amt)
 308         (if (> (- (point-max) pos) (point))
 309             (goto-char (- (point-max) pos)))
 310       (delete-region beg (point))
 311       (indent-to indent)
 312       ;; If initial point was within line's indentation,
 313       ;; position after the indentation.  Else stay at same point in text.
 314       (if (> (- (point-max) pos) (point))
 315           (goto-char (- (point-max) pos))))
 316     shift-amt))
 317
 318 (defun calculate-icon-indent (&optional parse-start)
 319   "Return appropriate indentation for current line as Icon code.
 320 In usual case returns an integer: the column to indent to.
 321 Returns nil if line starts inside a string, t if in a comment."
 322   (save-excursion
 323     (beginning-of-line)
 324     (let ((indent-point (point))
 325           (case-fold-search nil)
 326           state
 327           containing-sexp
 328           toplevel)
 329       (if parse-start
 330           (goto-char parse-start)
 331         (setq toplevel (beginning-of-icon-defun)))
 332       (while (< (point) indent-point)
 333         (setq parse-start (point))
 334         (setq state (parse-partial-sexp (point) indent-point 0))
 335         (setq containing-sexp (car (cdr state))))
 336       (cond ((or (nth 3 state) (nth 4 state))
 337              ;; return nil or t if should not change this line
 338              (nth 4 state))
 339             ((and containing-sexp
 340                   (/= (char-after containing-sexp) ?{))
 341              ;; line is expression, not statement:
 342              ;; indent to just after the surrounding open.
 343              (goto-char (1+ containing-sexp))
 344              (current-column))
 345             (t
 346               (if toplevel
 347                   ;; Outside any procedures.
 348                   (progn (icon-backward-to-noncomment (point-min))
 349                          (if (icon-is-continuation-line)
 350                              icon-continued-statement-offset 0))
 351                 ;; Statement level.
 352                 (if (null containing-sexp)
 353                     (progn (beginning-of-icon-defun)
 354                            (setq containing-sexp (point))))
 355                 (goto-char indent-point)
 356                 ;; Is it a continuation or a new statement?
 357                 ;; Find previous non-comment character.
 358                 (icon-backward-to-noncomment containing-sexp)
 359                 ;; Now we get the answer.
 360                 (if (icon-is-continuation-line)
 361                     ;; This line is continuation of preceding line's statement;
 362                     ;; indent  icon-continued-statement-offset  more than the
 363                     ;; first line of the statement.
 364                     (progn
 365                       (icon-backward-to-start-of-continued-exp containing-sexp)
 366                       (+ icon-continued-statement-offset (current-column)
 367                          (if (save-excursion (goto-char indent-point)
 368                                              (skip-chars-forward " \t")
 369                                              (eq (following-char) ?{))
 370                              icon-continued-brace-offset 0)))
 371                   ;; This line starts a new statement.
 372                   ;; Position following last unclosed open.
 373                   (goto-char containing-sexp)
 374                   ;; Is line first statement after an open-brace?
 375                   (or
 376                     ;; If no, find that first statement and indent like it.
 377                     (save-excursion
 378                       (if (looking-at "procedure\\s ")
 379                           (forward-sexp 3)
 380                         (forward-char 1))
 381                       (while (progn (skip-chars-forward " \t\n")
 382                                     (looking-at "#"))
 383                         ;; Skip over comments following openbrace.
 384                         (forward-line 1))
 385                       ;; The first following code counts
 386                       ;; if it is before the line we want to indent.
 387                       (and (< (point) indent-point)
 388                            (current-column)))
 389                     ;; If no previous statement,
 390                     ;; indent it relative to line brace is on.
 391                     ;; For open brace in column zero, don't let statement
 392                     ;; start there too.  If icon-indent-level is zero,
 393                     ;; use icon-brace-offset + icon-continued-statement-offset
 394                     ;; instead.
 395                     ;; For open-braces not the first thing in a line,
 396                     ;; add in icon-brace-imaginary-offset.
 397                     (+ (if (and (bolp) (zerop icon-indent-level))
 398                            (+ icon-brace-offset
 399                               icon-continued-statement-offset)
 400                          icon-indent-level)
 401                        ;; Move back over whitespace before the openbrace.
 402                        ;; If openbrace is not first nonwhite thing on the line,
 403                        ;; add the icon-brace-imaginary-offset.
 404                        (progn (skip-chars-backward " \t")
 405                               (if (bolp) 0 icon-brace-imaginary-offset))
 406                        ;; Get initial indentation of the line we are on.
 407                        (current-indentation))))))))))
 408
 409 ;; List of words to check for as the last thing on a line.
 410 ;; If cdr is t, next line is a continuation of the same statement,
 411 ;; if cdr is nil, next line starts a new (possibly indented) statement.
 412
 413 (defconst icon-resword-alist
 414   '(("by" . t) ("case" . t) ("create") ("do") ("dynamic" . t) ("else")
 415     ("every" . t) ("if" . t) ("global" . t) ("initial" . t)
 416     ("link" . t) ("local" . t) ("of") ("record" . t) ("repeat" . t)
 417     ("static" . t) ("then") ("to" . t) ("until" . t) ("while" . t)))
 418
 419 (defun icon-is-continuation-line ()
 420   (let* ((ch (preceding-char))
 421          (ch-syntax (char-syntax ch)))
 422     (if (eq ch-syntax ?w)
 423         (assoc (buffer-substring
 424                 (progn (forward-word -1) (point))
 425                 (progn (forward-word 1) (point)))
 426                icon-resword-alist)
 427       (not (memq ch '(0 ?\; ?\} ?\{ ?\) ?\] ?\" ?\' ?\# ?\, ?\. ?\n))))))
 428
 429 (defun icon-backward-to-noncomment (lim)
 430   (let (opoint stop)
 431     (while (not stop)
 432       (skip-chars-backward " \t\n\f" lim)
 433       (setq opoint (point))
 434       (beginning-of-line)
 435       (if (and (nth 5 (parse-partial-sexp (point) opoint))
 436                (< lim (point)))
 437           (search-backward "#")
 438         (setq stop t)))))
 439
 440 (defun icon-backward-to-start-of-continued-exp (lim)
 441   (if (memq (preceding-char) '(?\) ?\]))
 442       (forward-sexp -1))
 443   (beginning-of-line)
 444   (skip-chars-forward " \t")
 445   (cond
 446    ((<= (point) lim) (goto-char (1+ lim)))
 447    ((not (icon-is-continued-line)) 0)
 448    ((and (eq (char-syntax (following-char)) ?w)
 449          (cdr
 450           (assoc (buffer-substring (point)
 451                                    (save-excursion (forward-word 1) (point)))
 452                  icon-resword-alist))) 0)
 453    (t (end-of-line 0) (icon-backward-to-start-of-continued-exp lim))))
 454
 455 (defun icon-is-continued-line ()
 456   (save-excursion
 457     (end-of-line 0)
 458     (icon-is-continuation-line)))
 459
 460 (defun icon-backward-to-start-of-if (&optional limit)
 461   "Move to the start of the last \"unbalanced\" if."
 462   (or limit (setq limit (save-excursion (beginning-of-icon-defun) (point))))
 463   (let ((if-level 1)
 464         (case-fold-search nil))
 465     (while (not (zerop if-level))
 466       (backward-sexp 1)
 467       (cond ((looking-at "else\\b")
 468              (setq if-level (1+ if-level)))
 469             ((looking-at "if\\b")
 470              (setq if-level (1- if-level)))
 471             ((< (point) limit)
 472              (setq if-level 0)
 473              (goto-char limit))))))
 474 \f
 475 (defun mark-icon-function ()
 476   "Put mark at end of Icon function, point at beginning."
 477   (interactive)
 478   (push-mark (point))
 479   (end-of-icon-defun)
 480   (push-mark (point))
 481   (beginning-of-line 0)
 482   (beginning-of-icon-defun))
 483
 484 (defun beginning-of-icon-defun ()
 485   "Go to the start of the enclosing procedure; return t if at top level."
 486   (interactive)
 487   (if (re-search-backward "^procedure\\s \\|^end[ \t\n]" (point-min) 'move)
 488       (looking-at "e")
 489     t))
 490
 491 (defun end-of-icon-defun ()
 492   (interactive)
 493   (if (not (bobp)) (forward-char -1))
 494   (re-search-forward "\\(\\s \\|^\\)end\\(\\s \\|$\\)" (point-max) 'move)
 495   (forward-word -1)
 496   (forward-line 1))
 497 \f
 498 (defun indent-icon-exp ()
 499   "Indent each line of the Icon grouping following point."
 500   (interactive)
 501   (let ((indent-stack (list nil))
 502         (contain-stack (list (point)))
 503         (case-fold-search nil)
 504         restart outer-loop-done inner-loop-done state ostate
 505         this-indent last-sexp last-depth
 506         at-else at-brace at-do
 507         (opoint (point))
 508         (next-depth 0))
 509     (save-excursion
 510       (forward-sexp 1))
 511     (save-excursion
 512       (setq outer-loop-done nil)
 513       (while (and (not (eobp)) (not outer-loop-done))
 514         (setq last-depth next-depth)
 515         ;; Compute how depth changes over this line
 516         ;; plus enough other lines to get to one that
 517         ;; does not end inside a comment or string.
 518         ;; Meanwhile, do appropriate indentation on comment lines.
 519         (setq inner-loop-done nil)
 520         (while (and (not inner-loop-done)
 521                     (not (and (eobp) (setq outer-loop-done t))))
 522           (setq ostate state)
 523           (setq state (parse-partial-sexp (point) (progn (end-of-line) (point))
 524                                           nil nil state))
 525           (setq next-depth (car state))
 526           (if (and (car (cdr (cdr state)))
 527                    (>= (car (cdr (cdr state))) 0))
 528               (setq last-sexp (car (cdr (cdr state)))))
 529           (if (or (nth 4 ostate))
 530               (icon-indent-line))
 531           (if (or (nth 3 state))
 532               (forward-line 1)
 533             (setq inner-loop-done t)))
 534         (if (<= next-depth 0)
 535             (setq outer-loop-done t))
 536         (if outer-loop-done
 537             nil
 538           (if (/= last-depth next-depth)
 539               (setq last-sexp nil))
 540           (while (> last-depth next-depth)
 541             (setq indent-stack (cdr indent-stack)
 542                   contain-stack (cdr contain-stack)
 543                   last-depth (1- last-depth)))
 544           (while (< last-depth next-depth)
 545             (setq indent-stack (cons nil indent-stack)
 546                   contain-stack (cons nil contain-stack)
 547                   last-depth (1+ last-depth)))
 548           (if (null (car contain-stack))
 549               (setcar contain-stack (or (car (cdr state))
 550                                         (save-excursion (forward-sexp -1)
 551                                                         (point)))))
 552           (forward-line 1)
 553           (skip-chars-forward " \t")
 554           (if (eolp)
 555               nil
 556             (if (and (car indent-stack)
 557                      (>= (car indent-stack) 0))
 558                 ;; Line is on an existing nesting level.
 559                 ;; Lines inside parens are handled specially.
 560                 (if (/= (char-after (car contain-stack)) ?{)
 561                     (setq this-indent (car indent-stack))
 562                   ;; Line is at statement level.
 563                   ;; Is it a new statement?  Is it an else?
 564                   ;; Find last non-comment character before this line
 565                   (save-excursion
 566                     (setq at-else (looking-at "else\\W"))
 567                     (setq at-brace (= (following-char) ?{))
 568                     (icon-backward-to-noncomment opoint)
 569                     (if (icon-is-continuation-line)
 570                         ;; Preceding line did not end in comma or semi;
 571                         ;; indent this line  icon-continued-statement-offset
 572                         ;; more than previous.
 573                         (progn
 574                           (icon-backward-to-start-of-continued-exp (car contain-stack))
 575                           (setq this-indent
 576                                 (+ icon-continued-statement-offset (current-column)
 577                                    (if at-brace icon-continued-brace-offset 0))))
 578                       ;; Preceding line ended in comma or semi;
 579                       ;; use the standard indent for this level.
 580                       (if at-else
 581                           (progn (icon-backward-to-start-of-if opoint)
 582                                  (setq this-indent (current-indentation)))
 583                         (setq this-indent (car indent-stack))))))
 584               ;; Just started a new nesting level.
 585               ;; Compute the standard indent for this level.
 586               (let ((val (calculate-icon-indent
 587                            (if (car indent-stack)
 588                                (- (car indent-stack))))))
 589                 (setcar indent-stack
 590                         (setq this-indent val))))
 591             ;; Adjust line indentation according to its contents
 592             (if (or (= (following-char) ?})
 593                     (looking-at "end\\b"))
 594                 (setq this-indent (- this-indent icon-indent-level)))
 595             (if (= (following-char) ?{)
 596                 (setq this-indent (+ this-indent icon-brace-offset)))
 597             ;; Put chosen indentation into effect.
 598             (or (= (current-column) this-indent)
 599                 (progn
 600                   (delete-region (point) (progn (beginning-of-line) (point)))
 601                   (indent-to this-indent)))
 602             ;; Indent any comment following the text.
 603             (or (looking-at comment-start-skip)
 604                 (if (re-search-forward comment-start-skip (save-excursion (end-of-line) (point)) t)
 605                     (progn (indent-for-comment) (beginning-of-line))))))))))
 606
 607 (defconst icon-font-lock-keywords-1
 608   (eval-when-compile
 609     (list
 610      ;; Fontify procedure name definitions.
 611        '("^[ \t]*\\(procedure\\)\\>[ \t]*\\(\\sw+\\)?"
 612        (1 font-lock-builtin-face) (2 font-lock-function-name-face nil t))))
 613   "Subdued level highlighting for Icon mode.")
 614
 615 (defconst icon-font-lock-keywords-2
 616   (append
 617    icon-font-lock-keywords-1
 618    (eval-when-compile
 619      (list
 620       ;; Fontify all type specifiers.
 621       (cons
 622        (regexp-opt  '("null" "string" "co-expression" "table" "integer"
 623                       "cset"  "set" "real" "file" "list") 'words)
 624        'font-lock-type-face)
 625       ;; Fontify all keywords.
 626       ;;
 627       (cons
 628        (regexp-opt
 629         '("break" "do" "next" "repeat" "to" "by" "else" "if" "not" "return"
 630           "until" "case" "of" "while" "create" "every" "suspend" "default"
 631           "fail" "record" "then") 'words)
 632        'font-lock-keyword-face)
 633       ;; "end" "initial"
 634       (cons (regexp-opt '("end" "initial") 'words)
 635             'font-lock-builtin-face)
 636       ;; Fontify all system variables.
 637       (cons
 638        (regexp-opt
 639         '("&allocated" "&ascii" "&clock" "&col" "&collections" "&column"
 640           "&control" "&cset" "&current" "&date" "&dateline" "&digits" "&dump"
 641           "&e" "&error" "&errornumber" "&errortext" "&errorvalue" "&errout"
 642           "&eventcode" "&eventsource" "&eventvalue" "&fail" "&features"
 643           "&file" "&host" "&input" "&interval" "&lcase" "&ldrag" "&letters"
 644           "&level" "&line" "&lpress" "&lrelease" "&main" "&mdrag" "&meta"
 645           "&mpress" "&mrelease" "&null" "&output" "&phi" "&pi" "&pos"
 646           "&progname" "&random" "&rdrag" "&regions" "&resize" "&row"
 647           "&rpress" "&rrelease" "&shift" "&source" "&storage" "&subject"
 648           "&time" "&trace" "&ucase" "&version" "&window" "&x" "&y") t)
 649        'font-lock-constant-face)
 650       (cons      ;; global local static declarations and link files
 651        (concat
 652         "^[ \t]*"
 653         (regexp-opt '("global" "link" "local" "static") t)
 654         "\\(\\sw+\\>\\)*")
 655        '((1 font-lock-builtin-face)
 656          (font-lock-match-c-style-declaration-item-and-skip-to-next
 657           (goto-char (or (match-beginning 2) (match-end 1))) nil
 658           (1 (if (match-beginning 2)
 659                  font-lock-function-name-face
 660                font-lock-variable-name-face)))))
 661
 662       (cons      ;; $define $elif $ifdef $ifndef $undef
 663        (concat "^"
 664                (regexp-opt'("$define" "$elif" "$ifdef" "$ifndef" "$undef") t)
 665                "\\>[ \t]*\\([^ \t\n]+\\)?")
 666             '((1 font-lock-builtin-face)
 667               (4 font-lock-variable-name-face nil t)))
 668       (cons      ;; $dump $endif $else $include
 669        (concat
 670         "^" (regexp-opt'("$dump" "$endif" "$else" "$include") t) "\\>" )
 671        'font-lock-builtin-face)
 672       (cons      ;; $warning $error
 673        (concat "^" (regexp-opt '("$warning" "$error") t)
 674                "\\>[ \t]*\\(.+\\)?")
 675        '((1 font-lock-builtin-face) (3 font-lock-warning-face nil t))))))
 676   "Gaudy level highlighting for Icon mode.")
 677
 678 (defvar icon-font-lock-keywords icon-font-lock-keywords-1
 679   "Default expressions to highlight in `icon-mode'.")
 680
 681 ;;;used by hs-minor-mode
 682 (defun icon-forward-sexp-function (arg)
 683   (if (< arg 0)
 684       (beginning-of-icon-defun)
 685     (end-of-icon-defun)
 686     (forward-char -1)))
 687
 688 (provide 'icon)
 689
 690 ;;; arch-tag: 8abf8c99-e7df-44af-a58f-ef5ed2ee52cb
 691 ;;; icon.el ends here