code.delx.au - gnu-emacs/blob - lisp/emulation/viper-util.el

   1 ;;; viper-util.el --- Utilities used by viper.el
   2
   3 ;; Copyright (C) 1994, 1995, 1996, 1997 Free Software Foundation, Inc.
   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 2, 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 the
  19 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 ;; Boston, MA 02111-1307, USA.
  21
  22
  23 ;; Code
  24
  25 ;; Compiler pacifier
  26 (defvar viper-overriding-map)
  27 (defvar pm-color-alist)
  28 (defvar zmacs-region-stays)
  29 (defvar viper-minibuffer-current-face)
  30 (defvar viper-minibuffer-insert-face)
  31 (defvar viper-minibuffer-vi-face)
  32 (defvar viper-minibuffer-emacs-face)
  33 (defvar viper-replace-overlay-face)
  34 (defvar viper-fast-keyseq-timeout)
  35 (defvar ex-unix-type-shell)
  36 (defvar ex-unix-type-shell-options)
  37 (defvar viper-ex-tmp-buf-name)
  38 (defvar viper-syntax-preference)
  39
  40 (require 'cl)
  41 (require 'ring)
  42
  43 (if noninteractive
  44     (eval-when-compile
  45       (let ((load-path (cons (expand-file-name ".") load-path)))
  46         (or (featurep 'viper-init)
  47             (load "viper-init.el" nil nil 'nosuffix))
  48         )))
  49 ;; end pacifier
  50
  51 (require 'viper-init)
  52
  53
  54 ;; A fix for NeXT Step
  55 ;; Should go away, when NS people fix the design flaw, which leaves the
  56 ;; two x-* functions undefined.
  57 (if (and (not (fboundp 'x-display-color-p)) (fboundp 'ns-display-color-p))
  58     (fset 'x-display-color-p (symbol-function 'ns-display-color-p)))
  59 (if (and (not (fboundp 'x-color-defined-p)) (fboundp 'ns-color-defined-p))
  60       (fset 'x-color-defined-p (symbol-function 'ns-color-defined-p)))
  61
  62 \f
  63 ;;; XEmacs support
  64
  65
  66 (if viper-xemacs-p
  67     (progn
  68       (fset 'viper-read-event (symbol-function 'next-command-event))
  69       (fset 'viper-make-overlay (symbol-function 'make-extent))
  70       (fset 'viper-overlay-start (symbol-function 'extent-start-position))
  71       (fset 'viper-overlay-end (symbol-function 'extent-end-position))
  72       (fset 'viper-overlay-put (symbol-function 'set-extent-property))
  73       (fset 'viper-overlay-p (symbol-function 'extentp))
  74       (fset 'viper-overlay-get (symbol-function 'extent-property))
  75       (fset 'viper-move-overlay (symbol-function 'set-extent-endpoints))
  76       (fset 'viper-overlay-live-p (symbol-function 'extent-live-p))
  77       (if (viper-window-display-p)
  78           (fset 'viper-iconify (symbol-function 'iconify-frame)))
  79       (cond ((viper-has-face-support-p)
  80              (fset 'viper-get-face (symbol-function 'get-face))
  81              (fset 'viper-color-defined-p
  82                    (symbol-function 'valid-color-name-p))
  83              )))
  84   (fset 'viper-read-event (symbol-function 'read-event))
  85   (fset 'viper-make-overlay (symbol-function 'make-overlay))
  86   (fset 'viper-overlay-start (symbol-function 'overlay-start))
  87   (fset 'viper-overlay-end (symbol-function 'overlay-end))
  88   (fset 'viper-overlay-put (symbol-function 'overlay-put))
  89   (fset 'viper-overlay-p (symbol-function 'overlayp))
  90   (fset 'viper-overlay-get (symbol-function 'overlay-get))
  91   (fset 'viper-move-overlay (symbol-function 'move-overlay))
  92   (fset 'viper-overlay-live-p (symbol-function 'overlayp))
  93   (if (viper-window-display-p)
  94       (fset 'viper-iconify (symbol-function 'iconify-or-deiconify-frame)))
  95   (cond ((viper-has-face-support-p)
  96          (fset 'viper-get-face (symbol-function 'internal-get-face))
  97          (fset 'viper-color-defined-p (symbol-function 'x-color-defined-p))
  98          )))
  99
 100
 101 (fset 'viper-characterp
 102       (symbol-function
 103        (if viper-xemacs-p 'characterp 'integerp)))
 104
 105 (defsubst viper-color-display-p ()
 106   (if viper-emacs-p
 107       (x-display-color-p)
 108     (eq (device-class (selected-device)) 'color)))
 109
 110 (defsubst viper-get-cursor-color ()
 111   (if viper-emacs-p
 112       (cdr (assoc 'cursor-color (frame-parameters)))
 113     (color-instance-name (frame-property (selected-frame) 'cursor-color))))
 114
 115
 116 ;; OS/2
 117 (cond ((eq (viper-device-type) 'pm)
 118        (fset 'viper-color-defined-p
 119              (lambda (color) (assoc color pm-color-alist)))))
 120
 121
 122 ;; cursor colors
 123 (defun viper-change-cursor-color (new-color)
 124   (if (and (viper-window-display-p)  (viper-color-display-p)
 125            (stringp new-color) (viper-color-defined-p new-color)
 126            (not (string= new-color (viper-get-cursor-color))))
 127       (modify-frame-parameters
 128        (selected-frame) (list (cons 'cursor-color new-color)))))
 129
 130 ;; By default, saves current frame cursor color in the
 131 ;; viper-saved-cursor-color-in-replace-mode property of viper-replace-overlay
 132 (defun viper-save-cursor-color (before-which-mode)
 133   (if (and (viper-window-display-p) (viper-color-display-p))
 134       (let ((color (viper-get-cursor-color)))
 135         (if (and (stringp color) (viper-color-defined-p color)
 136                  (not (string= color viper-replace-overlay-cursor-color)))
 137             (modify-frame-parameters
 138              (selected-frame)
 139              (list
 140               (cons
 141                (if (eq before-which-mode 'before-replace-mode)
 142                    'viper-saved-cursor-color-in-replace-mode
 143                  'viper-saved-cursor-color-in-insert-mode)
 144                color)))
 145           ))))
 146
 147
 148 (defsubst viper-get-saved-cursor-color-in-replace-mode ()
 149   (or
 150    (funcall
 151     (if viper-emacs-p 'frame-parameter 'frame-property)
 152     (selected-frame)
 153     'viper-saved-cursor-color-in-replace-mode)
 154    viper-vi-state-cursor-color))
 155
 156 (defsubst viper-get-saved-cursor-color-in-insert-mode ()
 157   (or
 158    (funcall
 159     (if viper-emacs-p 'frame-parameter 'frame-property)
 160     (selected-frame)
 161     'viper-saved-cursor-color-in-insert-mode)
 162    viper-vi-state-cursor-color))
 163
 164 ;; restore cursor color from replace overlay
 165 (defun viper-restore-cursor-color(after-which-mode)
 166   (if (viper-overlay-p viper-replace-overlay)
 167       (viper-change-cursor-color
 168        (if (eq after-which-mode 'after-replace-mode)
 169            (viper-get-saved-cursor-color-in-replace-mode)
 170          (viper-get-saved-cursor-color-in-insert-mode))
 171        )))
 172
 173 \f
 174 ;; Check the current version against the major and minor version numbers
 175 ;; using op: cur-vers op major.minor If emacs-major-version or
 176 ;; emacs-minor-version are not defined, we assume that the current version
 177 ;; is hopelessly outdated.  We assume that emacs-major-version and
 178 ;; emacs-minor-version are defined.  Otherwise, for Emacs/XEmacs 19, if the
 179 ;; current minor version is < 10 (xemacs) or < 23 (emacs) the return value
 180 ;; will be nil (when op is =, >, or >=) and t (when op is <, <=), which may be
 181 ;; incorrect.  However, this gives correct result in our cases, since we are
 182 ;; testing for sufficiently high Emacs versions.
 183 (defun viper-check-version (op major minor &optional type-of-emacs)
 184   (if (and (boundp 'emacs-major-version) (boundp 'emacs-minor-version))
 185       (and (cond ((eq type-of-emacs 'xemacs) viper-xemacs-p)
 186                  ((eq type-of-emacs 'emacs) viper-emacs-p)
 187                  (t t))
 188            (cond ((eq op '=) (and (= emacs-minor-version minor)
 189                                   (= emacs-major-version major)))
 190                  ((memq op '(> >= < <=))
 191                   (and (or (funcall op emacs-major-version major)
 192                            (= emacs-major-version major))
 193                        (if (= emacs-major-version major)
 194                            (funcall op emacs-minor-version minor)
 195                          t)))
 196                  (t
 197                   (error "%S: Invalid op in viper-check-version" op))))
 198     (cond ((memq op '(= > >=)) nil)
 199           ((memq op '(< <=)) t))))
 200
 201
 202 (defun viper-get-visible-buffer-window (wind)
 203   (if viper-xemacs-p
 204       (get-buffer-window wind t)
 205     (get-buffer-window wind 'visible)))
 206
 207
 208 ;; Return line position.
 209 ;; If pos is 'start then returns position of line start.
 210 ;; If pos is 'end, returns line end.  If pos is 'mid, returns line center.
 211 ;; Pos = 'indent returns beginning of indentation.
 212 ;; Otherwise, returns point.  Current point is not moved in any case."
 213 (defun viper-line-pos (pos)
 214   (let ((cur-pos (point))
 215         (result))
 216     (cond
 217      ((equal pos 'start)
 218       (beginning-of-line))
 219      ((equal pos 'end)
 220       (end-of-line))
 221      ((equal pos 'mid)
 222       (goto-char (+ (viper-line-pos 'start) (viper-line-pos 'end) 2)))
 223      ((equal pos 'indent)
 224       (back-to-indentation))
 225      (t   nil))
 226     (setq result (point))
 227     (goto-char cur-pos)
 228     result))
 229
 230 ;; Emacs counts each multibyte character as several positions in the buffer, so
 231 ;; we use Emacs' chars-in-region.  XEmacs is counting each char as just one pos,
 232 ;; so we can simply subtract.
 233 (defun viper-chars-in-region (beg end &optional preserve-sign)
 234   (let ((count (abs (if (fboundp 'chars-in-region)
 235                         (chars-in-region beg end)
 236                       (- end beg)))))
 237     (if (and (< end beg) preserve-sign)
 238         (- count)
 239       count)))
 240
 241 ;; Test if POS is between BEG and END
 242 (defsubst viper-pos-within-region (pos beg end)
 243   (and (>= pos (min beg end)) (>= (max beg end) pos)))
 244
 245
 246 ;; Like move-marker but creates a virgin marker if arg isn't already a marker.
 247 ;; The first argument must eval to a variable name.
 248 ;; Arguments: (var-name position &optional buffer).
 249 ;;
 250 ;; This is useful for moving markers that are supposed to be local.
 251 ;; For this, VAR-NAME should be made buffer-local with nil as a default.
 252 ;; Then, each time this var is used in `viper-move-marker-locally' in a new
 253 ;; buffer, a new marker will be created.
 254 (defun viper-move-marker-locally (var pos &optional buffer)
 255   (if (markerp (eval var))
 256       ()
 257     (set var (make-marker)))
 258   (move-marker (eval var) pos buffer))
 259
 260
 261 ;; Print CONDITIONS as a message.
 262 (defun viper-message-conditions (conditions)
 263   (let ((case (car conditions)) (msg (cdr conditions)))
 264     (if (null msg)
 265         (message "%s" case)
 266       (message "%s: %s" case (mapconcat 'prin1-to-string msg " ")))
 267     (beep 1)))
 268
 269
 270 \f
 271 ;;; List/alist utilities
 272
 273 ;; Convert LIST to an alist
 274 (defun viper-list-to-alist (lst)
 275   (let ((alist))
 276     (while lst
 277       (setq alist (cons (list (car lst)) alist))
 278       (setq lst (cdr lst)))
 279     alist))
 280
 281 ;; Convert ALIST to a list.
 282 (defun viper-alist-to-list (alst)
 283   (let ((lst))
 284     (while alst
 285       (setq lst (cons (car (car alst)) lst))
 286       (setq alst (cdr alst)))
 287     lst))
 288
 289 ;; Filter ALIST using REGEXP.  Return alist whose elements match the regexp.
 290 (defun viper-filter-alist (regexp alst)
 291   (interactive "s x")
 292   (let ((outalst) (inalst alst))
 293     (while (car inalst)
 294       (if (string-match regexp (car (car inalst)))
 295           (setq outalst (cons (car inalst) outalst)))
 296       (setq inalst (cdr inalst)))
 297     outalst))
 298
 299 ;; Filter LIST using REGEXP.  Return list whose elements match the regexp.
 300 (defun viper-filter-list (regexp lst)
 301   (interactive "s x")
 302   (let ((outlst) (inlst lst))
 303     (while (car inlst)
 304       (if (string-match regexp (car inlst))
 305           (setq outlst (cons (car inlst) outlst)))
 306       (setq inlst (cdr inlst)))
 307     outlst))
 308
 309
 310 ;; Append LIS2 to LIS1, both alists, by side-effect and returns LIS1
 311 ;; LIS2 is modified by filtering it: deleting its members of the form
 312 ;; \(car elt\) such that (car elt') is in LIS1.
 313 (defun viper-append-filter-alist (lis1 lis2)
 314   (let ((temp lis1)
 315         elt)
 316
 317     ;;filter-append the second list
 318     (while temp
 319       ;; delete all occurrences
 320       (while (setq elt (assoc (car (car temp)) lis2))
 321         (setq lis2 (delq elt lis2)))
 322       (setq temp (cdr temp)))
 323
 324     (nconc lis1 lis2)))
 325
 326 \f
 327 ;;; Support for :e, :r, :w file globbing
 328
 329 ;; Glob the file spec.
 330 ;; This function is designed to work under Unix.  It might also work under VMS.
 331 (defun viper-glob-unix-files (filespec)
 332   (let ((gshell
 333          (cond (ex-unix-type-shell shell-file-name)
 334                ((memq system-type '(vax-vms axp-vms)) "*dcl*") ; VAX VMS
 335                (t "sh"))) ; probably Unix anyway
 336         (gshell-options
 337          ;; using cond in anticipation of further additions
 338          (cond (ex-unix-type-shell-options)
 339                ))
 340         (command (cond (viper-ms-style-os-p (format "\"ls -1 -d %s\"" filespec))
 341                        (t (format "ls -1 -d %s" filespec))))
 342         status)
 343     (save-excursion
 344       (set-buffer (get-buffer-create viper-ex-tmp-buf-name))
 345       (erase-buffer)
 346       (setq status
 347             (if gshell-options
 348                 (call-process gshell nil t nil
 349                               gshell-options
 350                               "-c"
 351                               command)
 352               (call-process gshell nil t nil
 353                             "-c"
 354                             command)))
 355       (goto-char (point-min))
 356       ;; Issue an error, if no match.
 357       (if (> status 0)
 358           (save-excursion
 359             (skip-chars-forward " \t\n\j")
 360             (if (looking-at "ls:")
 361                 (viper-forward-Word 1))
 362             (error "%s: %s"
 363                    (if (stringp  gshell)
 364                        gshell
 365                      "shell")
 366                    (buffer-substring (point) (viper-line-pos 'end)))
 367             ))
 368       (goto-char (point-min))
 369       (viper-get-filenames-from-buffer 'one-per-line))
 370     ))
 371
 372
 373 ;; Interpret the stuff in the buffer as a list of file names
 374 ;; return a list of file names listed in the buffer beginning at point
 375 ;; If optional arg is supplied, assume each filename is listed on a separate
 376 ;; line
 377 (defun viper-get-filenames-from-buffer (&optional one-per-line)
 378   (let ((skip-chars (if one-per-line "\t\n" " \t\n"))
 379          result fname delim)
 380     (skip-chars-forward skip-chars)
 381     (while (not (eobp))
 382       (if (cond ((looking-at "\"")
 383                  (setq delim ?\")
 384                  (re-search-forward "[^\"]+" nil t)) ; noerror
 385                 ((looking-at "'")
 386                  (setq delim ?')
 387                  (re-search-forward "[^']+" nil t)) ; noerror
 388                 (t
 389                  (re-search-forward
 390                   (concat "[^" skip-chars "]+") nil t))) ;noerror
 391           (setq fname
 392                 (buffer-substring (match-beginning 0) (match-end 0))))
 393       (if delim
 394           (forward-char 1))
 395       (skip-chars-forward " \t\n")
 396       (setq result (cons fname result)))
 397     result))
 398
 399 ;; convert MS-DOS wildcards to regexp
 400 (defun viper-wildcard-to-regexp (wcard)
 401   (save-excursion
 402     (set-buffer (get-buffer-create viper-ex-tmp-buf-name))
 403     (erase-buffer)
 404     (insert wcard)
 405     (goto-char (point-min))
 406     (while (not (eobp))
 407       (skip-chars-forward "^*?.\\\\")
 408       (cond ((eq (char-after (point)) ?*) (insert ".")(forward-char 1))
 409             ((eq (char-after (point)) ?.) (insert "\\")(forward-char 1))
 410             ((eq (char-after (point)) ?\\) (insert "\\")(forward-char 1))
 411             ((eq (char-after (point)) ??) (delete-char 1)(insert ".")))
 412       )
 413     (buffer-string)
 414     ))
 415
 416
 417 ;; glob windows files
 418 ;; LIST is expected to be in reverse order
 419 (defun viper-glob-mswindows-files (filespec)
 420   (let ((case-fold-search t)
 421         tmp tmp2)
 422     (save-excursion
 423       (set-buffer (get-buffer-create viper-ex-tmp-buf-name))
 424       (erase-buffer)
 425       (insert filespec)
 426       (goto-char (point-min))
 427       (setq tmp (viper-get-filenames-from-buffer))
 428       (while tmp
 429         (setq tmp2 (cons (directory-files
 430                           ;; the directory part
 431                           (or (file-name-directory (car tmp))
 432                               "")
 433                           t  ; return full names
 434                           ;; the regexp part: globs the file names
 435                           (concat "^"
 436                                   (viper-wildcard-to-regexp
 437                                    (file-name-nondirectory (car tmp)))
 438                                   "$"))
 439                          tmp2))
 440         (setq tmp (cdr tmp)))
 441       (reverse (apply 'append tmp2)))))
 442
 443 \f
 444 ;;; Insertion ring
 445
 446 ;; Rotate RING's index.  DIRection can be positive or negative.
 447 (defun viper-ring-rotate1 (ring dir)
 448   (if (and (ring-p ring) (> (ring-length ring) 0))
 449       (progn
 450         (setcar ring (cond ((> dir 0)
 451                             (ring-plus1 (car ring) (ring-length ring)))
 452                            ((< dir 0)
 453                             (ring-minus1 (car ring) (ring-length ring)))
 454                            ;; don't rotate if dir = 0
 455                            (t (car ring))))
 456         (viper-current-ring-item ring)
 457         )))
 458
 459 (defun viper-special-ring-rotate1 (ring dir)
 460   (if (memq viper-intermediate-command
 461             '(repeating-display-destructive-command
 462               repeating-insertion-from-ring))
 463       (viper-ring-rotate1 ring dir)
 464     ;; don't rotate otherwise
 465     (viper-ring-rotate1 ring 0)))
 466
 467 ;; current ring item; if N is given, then so many items back from the
 468 ;; current
 469 (defun viper-current-ring-item (ring &optional n)
 470   (setq n (or n 0))
 471   (if (and (ring-p ring) (> (ring-length ring) 0))
 472       (aref (cdr (cdr ring)) (mod (- (car ring) 1 n) (ring-length ring)))))
 473
 474 ;; Push item onto ring.  The second argument is a ring-variable, not value.
 475 (defun viper-push-onto-ring (item ring-var)
 476   (or (ring-p (eval ring-var))
 477       (set ring-var (make-ring (eval (intern (format "%S-size" ring-var))))))
 478   (or (null item) ; don't push nil
 479       (and (stringp item) (string= item "")) ; or empty strings
 480       (equal item (viper-current-ring-item (eval ring-var))) ; or old stuff
 481       ;; Since viper-set-destructive-command checks if we are inside
 482       ;; viper-repeat, we don't check whether this-command-keys is a `.'.  The
 483       ;; cmd viper-repeat makes a call to the current function only if `.' is
 484       ;; executing a command from the command history.  It doesn't call the
 485       ;; push-onto-ring function if `.' is simply repeating the last
 486       ;; destructive command.  We only check for ESC (which happens when we do
 487       ;; insert with a prefix argument, or if this-command-keys doesn't give
 488       ;; anything meaningful (in that case we don't know what to show to the
 489       ;; user).
 490       (and (eq ring-var 'viper-command-ring)
 491            (string-match "\\([0-9]*\e\\|^[ \t]*$\\|escape\\)"
 492                          (viper-array-to-string (this-command-keys))))
 493       (viper-ring-insert (eval ring-var) item))
 494   )
 495
 496
 497 ;; removing elts from ring seems to break it
 498 (defun viper-cleanup-ring (ring)
 499   (or (< (ring-length ring) 2)
 500       (null (viper-current-ring-item ring))
 501       ;; last and previous equal
 502       (if (equal (viper-current-ring-item ring)
 503                  (viper-current-ring-item ring 1))
 504           (viper-ring-pop ring))))
 505
 506 ;; ring-remove seems to be buggy, so we concocted this for our purposes.
 507 (defun viper-ring-pop (ring)
 508   (let* ((ln (ring-length ring))
 509          (vec (cdr (cdr ring)))
 510          (veclen (length vec))
 511          (hd (car ring))
 512          (idx (max 0 (ring-minus1 hd ln)))
 513          (top-elt (aref vec idx)))
 514
 515         ;; shift elements
 516         (while (< (1+ idx) veclen)
 517           (aset vec idx (aref vec (1+ idx)))
 518           (setq idx (1+ idx)))
 519         (aset vec idx nil)
 520
 521         (setq hd (max 0 (ring-minus1 hd ln)))
 522         (if (= hd (1- ln)) (setq hd 0))
 523         (setcar ring hd) ; move head
 524         (setcar (cdr ring) (max 0 (1- ln))) ; adjust length
 525         top-elt
 526         ))
 527
 528 (defun viper-ring-insert (ring item)
 529   (let* ((ln (ring-length ring))
 530          (vec (cdr (cdr ring)))
 531          (veclen (length vec))
 532          (hd (car ring))
 533          (vecpos-after-hd (if (= hd 0) ln hd))
 534          (idx ln))
 535
 536     (if (= ln veclen)
 537         (progn
 538           (aset vec hd item) ; hd is always 1+ the actual head index in vec
 539           (setcar ring (ring-plus1 hd ln)))
 540       (setcar (cdr ring) (1+ ln))
 541       (setcar ring (ring-plus1 vecpos-after-hd (1+ ln)))
 542       (while (and (>= idx vecpos-after-hd) (> ln 0))
 543         (aset vec idx (aref vec (1- idx)))
 544         (setq idx (1- idx)))
 545       (aset vec vecpos-after-hd item))
 546     item))
 547
 548 \f
 549 ;;; String utilities
 550
 551 ;; If STRING is longer than MAX-LEN, truncate it and print ...... instead
 552 ;; PRE-STRING is a string to prepend to the abbrev string.
 553 ;; POST-STRING is a string to append to the abbrev string.
 554 ;; ABBREV_SIGN is a string to be inserted before POST-STRING
 555 ;; if the orig string was truncated.
 556 (defun viper-abbreviate-string (string max-len
 557                                      pre-string post-string abbrev-sign)
 558   (let (truncated-str)
 559     (setq truncated-str
 560           (if (stringp string)
 561               (substring string 0 (min max-len (length string)))))
 562     (cond ((null truncated-str) "")
 563           ((> (length string) max-len)
 564            (format "%s%s%s%s"
 565                    pre-string truncated-str abbrev-sign post-string))
 566           (t (format "%s%s%s" pre-string truncated-str post-string)))))
 567
 568 ;; tells if we are over a whitespace-only line
 569 (defsubst viper-over-whitespace-line ()
 570   (save-excursion
 571     (beginning-of-line)
 572     (looking-at "^[ \t]*$")))
 573
 574 \f
 575 ;;; Saving settings in custom file
 576
 577 ;; Save the current setting of VAR in CUSTOM-FILE.
 578 ;; If given, MESSAGE is a message to be displayed after that.
 579 ;; This message is erased after 2 secs, if erase-msg is non-nil.
 580 ;; Arguments: var message custom-file &optional erase-message
 581 (defun viper-save-setting (var message custom-file &optional erase-msg)
 582   (let* ((var-name (symbol-name var))
 583          (var-val (if (boundp var) (eval var)))
 584          (regexp (format "^[^;]*%s[ \t\n]*[a-zA-Z---_']*[ \t\n)]" var-name))
 585          (buf (find-file-noselect (substitute-in-file-name custom-file)))
 586         )
 587     (message message)
 588     (save-excursion
 589       (set-buffer buf)
 590       (goto-char (point-min))
 591       (if (re-search-forward regexp nil t)
 592           (let ((reg-end (1- (match-end 0))))
 593             (search-backward var-name)
 594             (delete-region (match-beginning 0) reg-end)
 595             (goto-char (match-beginning 0))
 596             (insert (format "%s  '%S" var-name var-val)))
 597         (goto-char (point-max))
 598         (if (not (bolp)) (insert "\n"))
 599         (insert (format "(setq %s '%S)\n" var-name var-val)))
 600       (save-buffer))
 601       (kill-buffer buf)
 602       (if erase-msg
 603           (progn
 604             (sit-for 2)
 605             (message "")))
 606       ))
 607
 608 ;; Save STRING in CUSTOM-FILE.  If PATTERN is non-nil, remove strings that
 609 ;; match this pattern.
 610 (defun viper-save-string-in-file (string custom-file &optional pattern)
 611   (let ((buf (find-file-noselect (substitute-in-file-name custom-file))))
 612     (save-excursion
 613       (set-buffer buf)
 614       (let (buffer-read-only)
 615         (goto-char (point-min))
 616         (if pattern (delete-matching-lines pattern))
 617         (goto-char (point-max))
 618         (if string (insert string))
 619         (save-buffer)))
 620     (kill-buffer buf)
 621     ))
 622
 623
 624 ;; define remote file test
 625 (or (fboundp 'viper-file-remote-p) ; user supplied his own function: use it
 626     (defun viper-file-remote-p (file-name)
 627       (car (cond ((featurep 'efs-auto) (efs-ftp-path file-name))
 628                  ((fboundp 'file-remote-p) (file-remote-p file-name))
 629                  (t (require 'ange-ftp)
 630                     ;; Can happen only in Emacs, since XEmacs has file-remote-p
 631                     (ange-ftp-ftp-name file-name))))))
 632
 633
 634
 635 ;; This is a simple-minded check for whether a file is under version control.
 636 ;; If file,v exists but file doesn't, this file is considered to be not checked
 637 ;; in and not checked out for the purpose of patching (since patch won't be
 638 ;; able to read such a file anyway).
 639 ;; FILE is a string representing file name
 640 ;;(defun viper-file-under-version-control (file)
 641 ;;  (let* ((filedir (file-name-directory file))
 642 ;;       (file-nondir (file-name-nondirectory file))
 643 ;;       (trial (concat file-nondir ",v"))
 644 ;;       (full-trial (concat filedir trial))
 645 ;;       (full-rcs-trial (concat filedir "RCS/" trial)))
 646 ;;    (and (stringp file)
 647 ;;       (file-exists-p file)
 648 ;;       (or
 649 ;;        (and
 650 ;;         (file-exists-p full-trial)
 651 ;;         ;; in FAT FS, `file,v' and `file' may turn out to be the same!
 652 ;;         ;; don't be fooled by this!
 653 ;;         (not (equal (file-attributes file)
 654 ;;                     (file-attributes full-trial))))
 655 ;;        ;; check if a version is in RCS/ directory
 656 ;;        (file-exists-p full-rcs-trial)))
 657 ;;       ))
 658
 659
 660 (defsubst viper-file-checked-in-p (file)
 661   (and (featurep 'vc-hooks)
 662        ;; CVS files are considered not checked in
 663        (not (memq (vc-backend file) '(nil CVS)))
 664        (not (vc-locking-user file))))
 665
 666 ;; checkout if visited file is checked in
 667 (defun viper-maybe-checkout (buf)
 668   (let ((file (expand-file-name (buffer-file-name buf)))
 669         (checkout-function (key-binding "\C-x\C-q")))
 670     (if (and (viper-file-checked-in-p file)
 671              (or (beep 1) t)
 672              (y-or-n-p
 673               (format
 674                "File %s is checked in.  Check it out? "
 675                (viper-abbreviate-file-name file))))
 676         (with-current-buffer buf
 677           (command-execute checkout-function)))))
 678
 679
 680
 681 \f
 682 ;;; Overlays
 683
 684 ;; Search
 685
 686 (defun viper-flash-search-pattern ()
 687   (if (viper-overlay-p viper-search-overlay)
 688       (viper-move-overlay
 689        viper-search-overlay (match-beginning 0) (match-end 0))
 690     (setq viper-search-overlay
 691           (viper-make-overlay
 692            (match-beginning 0) (match-end 0) (current-buffer))))
 693
 694   (viper-overlay-put
 695    viper-search-overlay 'priority viper-search-overlay-priority)
 696   (if (viper-has-face-support-p)
 697       (progn
 698         (viper-overlay-put viper-search-overlay 'face viper-search-face)
 699         (sit-for 2)
 700         (viper-overlay-put viper-search-overlay 'face nil))))
 701
 702
 703 ;; Replace state
 704
 705 (defsubst viper-move-replace-overlay (beg end)
 706   (viper-move-overlay viper-replace-overlay beg end))
 707
 708 (defun viper-set-replace-overlay (beg end)
 709   (if (viper-overlay-live-p viper-replace-overlay)
 710       (viper-move-replace-overlay beg end)
 711     (setq viper-replace-overlay (viper-make-overlay beg end (current-buffer)))
 712     ;; never detach
 713     (viper-overlay-put
 714      viper-replace-overlay (if viper-emacs-p 'evaporate 'detachable) nil)
 715     (viper-overlay-put
 716      viper-replace-overlay 'priority viper-replace-overlay-priority)
 717     ;; If Emacs will start supporting overlay maps, as it currently supports
 718     ;; text-property maps, we could do away with viper-replace-minor-mode and
 719     ;; just have keymap attached to replace overlay.
 720     ;;(viper-overlay-put
 721     ;; viper-replace-overlay
 722     ;; (if viper-xemacs-p 'keymap 'local-map)
 723     ;; viper-replace-map)
 724     )
 725   (if (viper-has-face-support-p)
 726       (viper-overlay-put
 727        viper-replace-overlay 'face viper-replace-overlay-face))
 728   (viper-save-cursor-color 'before-replace-mode)
 729   (viper-change-cursor-color viper-replace-overlay-cursor-color)
 730   )
 731
 732
 733 (defun viper-set-replace-overlay-glyphs (before-glyph after-glyph)
 734   (or (viper-overlay-live-p viper-replace-overlay)
 735       (viper-set-replace-overlay (point-min) (point-min)))
 736   (if (or (not (viper-has-face-support-p))
 737           viper-use-replace-region-delimiters)
 738       (let ((before-name (if viper-xemacs-p 'begin-glyph 'before-string))
 739             (after-name (if viper-xemacs-p 'end-glyph 'after-string)))
 740         (viper-overlay-put viper-replace-overlay before-name before-glyph)
 741         (viper-overlay-put viper-replace-overlay after-name after-glyph))))
 742
 743 (defun viper-hide-replace-overlay ()
 744   (viper-set-replace-overlay-glyphs nil nil)
 745   (viper-restore-cursor-color 'after-replace-mode)
 746   (viper-restore-cursor-color 'after-insert-mode)
 747   (if (viper-has-face-support-p)
 748       (viper-overlay-put viper-replace-overlay 'face nil)))
 749
 750
 751 (defsubst viper-replace-start ()
 752   (viper-overlay-start viper-replace-overlay))
 753 (defsubst viper-replace-end ()
 754   (viper-overlay-end viper-replace-overlay))
 755
 756
 757 ;; Minibuffer
 758
 759 (defun viper-set-minibuffer-overlay ()
 760   (viper-check-minibuffer-overlay)
 761   (if (viper-has-face-support-p)
 762       (progn
 763         (viper-overlay-put
 764          viper-minibuffer-overlay 'face viper-minibuffer-current-face)
 765         (viper-overlay-put
 766          viper-minibuffer-overlay 'priority viper-minibuffer-overlay-priority)
 767         ;; never detach
 768         (viper-overlay-put
 769          viper-minibuffer-overlay
 770          (if viper-emacs-p 'evaporate 'detachable)
 771          nil)
 772         ;; make viper-minibuffer-overlay open-ended
 773         ;; In emacs, it is made open ended at creation time
 774         (if viper-xemacs-p
 775             (progn
 776               (viper-overlay-put viper-minibuffer-overlay 'start-open nil)
 777               (viper-overlay-put viper-minibuffer-overlay 'end-open nil)))
 778         )))
 779
 780 (defun viper-check-minibuffer-overlay ()
 781   (or (viper-overlay-p viper-minibuffer-overlay)
 782       (setq viper-minibuffer-overlay
 783             (if viper-xemacs-p
 784                 (viper-make-overlay 1 (1+ (buffer-size)) (current-buffer))
 785               ;; make overlay open-ended
 786               (viper-make-overlay
 787                1 (1+ (buffer-size)) (current-buffer) nil 'rear-advance)))
 788       ))
 789
 790
 791 (defsubst viper-is-in-minibuffer ()
 792   (save-match-data
 793     (string-match "\*Minibuf-" (buffer-name))))
 794
 795
 796 \f
 797 ;;; XEmacs compatibility
 798
 799 (defun viper-abbreviate-file-name (file)
 800   (if viper-emacs-p
 801       (abbreviate-file-name file)
 802     ;; XEmacs requires addl argument
 803     (abbreviate-file-name file t)))
 804
 805 ;; Sit for VAL milliseconds.  XEmacs doesn't support the millisecond arg
 806 ;; in sit-for, so this function smoothes out the differences.
 807 (defsubst viper-sit-for-short (val &optional nodisp)
 808   (if viper-xemacs-p
 809       (sit-for (/ val 1000.0) nodisp)
 810     (sit-for 0 val nodisp)))
 811
 812 ;; EVENT may be a single event of a sequence of events
 813 (defsubst viper-ESC-event-p (event)
 814   (let ((ESC-keys '(?\e (control \[) escape))
 815         (key (viper-event-key event)))
 816     (member key ESC-keys)))
 817
 818 ;; checks if object is a marker, has a buffer, and points to within that buffer
 819 (defun viper-valid-marker (marker)
 820   (if (and (markerp marker) (marker-buffer marker))
 821       (let ((buf (marker-buffer marker))
 822             (pos (marker-position marker)))
 823         (save-excursion
 824           (set-buffer buf)
 825           (and (<= pos (point-max)) (<= (point-min) pos))))))
 826
 827 (defsubst viper-mark-marker ()
 828   (if viper-xemacs-p
 829       (mark-marker t)
 830     (mark-marker)))
 831
 832 ;; like (set-mark-command nil) but doesn't push twice, if (car mark-ring)
 833 ;; is the same as (mark t).
 834 (defsubst viper-set-mark-if-necessary ()
 835   (setq mark-ring (delete (viper-mark-marker) mark-ring))
 836   (set-mark-command nil)
 837   (setq viper-saved-mark (point)))
 838
 839 ;; In transient mark mode (zmacs mode), it is annoying when regions become
 840 ;; highlighted due to Viper's pushing marks.  So, we deactivate marks, unless
 841 ;; the user explicitly wants highlighting, e.g., by hitting '' or ``
 842 (defun viper-deactivate-mark ()
 843   (if viper-xemacs-p
 844       (zmacs-deactivate-region)
 845     (deactivate-mark)))
 846
 847 (defsubst viper-leave-region-active ()
 848   (if viper-xemacs-p
 849       (setq zmacs-region-stays t)))
 850
 851 ;; Check if arg is a valid character for register
 852 ;; TYPE is a list that can contain `letter', `Letter', and `digit'.
 853 ;; Letter means lowercase letters, Letter means uppercase letters, and
 854 ;; digit means digits from 1 to 9.
 855 ;; If TYPE is nil, then down/uppercase letters and digits are allowed.
 856 (defun viper-valid-register (reg &optional type)
 857   (or type (setq type '(letter Letter digit)))
 858   (or (if (memq 'letter type)
 859           (and (<= ?a reg) (<= reg ?z)))
 860       (if (memq 'digit type)
 861           (and (<= ?1 reg) (<= reg ?9)))
 862       (if (memq 'Letter type)
 863           (and (<= ?A reg) (<= reg ?Z)))
 864       ))
 865
 866
 867 (defsubst viper-events-to-keys (events)
 868   (cond (viper-xemacs-p (events-to-keys events))
 869         (t events)))
 870
 871
 872 ;; it is suggested that an event must be copied before it is assigned to
 873 ;; last-command-event in XEmacs
 874 (defun viper-copy-event (event)
 875   (if viper-xemacs-p
 876       (copy-event event)
 877     event))
 878
 879 ;; like read-event, but in XEmacs also try to convert to char, if possible
 880 (defun viper-read-event-convert-to-char ()
 881   (let (event)
 882     (if viper-emacs-p
 883         (read-event)
 884       (setq event (next-command-event))
 885       (or (event-to-character event)
 886           event))
 887     ))
 888
 889 ;; This function lets function-key-map convert key sequences into logical
 890 ;; keys.  This does a better job than viper-read-event when it comes to kbd
 891 ;; macros, since it enables certain macros to be shared between X and TTY modes
 892 ;; by correctly mapping key sequences for Left/Right/... (one an ascii
 893 ;; terminal) into logical keys left, right, etc.
 894 (defun viper-read-key ()
 895   (let ((overriding-local-map viper-overriding-map)
 896         (inhibit-quit t)
 897         help-char key)
 898     (use-global-map viper-overriding-map)
 899     (unwind-protect
 900         (setq key (elt (read-key-sequence nil) 0))
 901       (use-global-map global-map))
 902     key))
 903
 904
 905 ;; Emacs has a bug in eventp, which causes (eventp nil) to return (nil)
 906 ;; instead of nil, if '(nil) was previously inadvertently assigned to
 907 ;; unread-command-events
 908 (defun viper-event-key (event)
 909   (or (and event (eventp event))
 910       (error "viper-event-key: Wrong type argument, eventp, %S" event))
 911   (when (cond (viper-xemacs-p (or (key-press-event-p event)
 912                                   (mouse-event-p event)))
 913               (t t))
 914     (let ((mod (event-modifiers event))
 915           basis)
 916       (setq basis
 917             (cond
 918              (viper-xemacs-p
 919               (cond ((key-press-event-p event)
 920                      (event-key event))
 921                     ((button-event-p event)
 922                      (concat "mouse-" (prin1-to-string (event-button event))))
 923                     (t
 924                      (error "viper-event-key: Unknown event, %S" event))))
 925              (t
 926               ;; Emacs doesn't handle capital letters correctly, since
 927               ;; \S-a isn't considered the same as A (it behaves as
 928               ;; plain `a' instead).  So we take care of this here
 929               (cond ((and (viper-characterp event) (<= ?A event) (<= event ?Z))
 930                      (setq mod nil
 931                            event event))
 932                     ;; Emacs has the oddity whereby characters 128+char
 933                     ;; represent M-char *if* this appears inside a string.
 934                     ;; So, we convert them manually to (meta char).
 935                     ((and (viper-characterp event)
 936                           (< ?\C-? event) (<= event 255))
 937                      (setq mod '(meta)
 938                            event (- event ?\C-? 1)))
 939                     ((and (null mod) (eq event 'return))
 940                      (setq event ?\C-m))
 941                     ((and (null mod) (eq event 'space))
 942                      (setq event ?\ ))
 943                     ((and (null mod) (eq event 'delete))
 944                      (setq event ?\C-?))
 945                     ((and (null mod) (eq event 'backspace))
 946                      (setq event ?\C-h))
 947                     (t (event-basic-type event)))
 948               )))
 949       (if (viper-characterp basis)
 950           (setq basis
 951                 (if (= basis ?\C-?)
 952                     (list 'control '\?) ; taking care of an emacs bug
 953                   (intern (char-to-string basis)))))
 954       (if mod
 955           (append mod (list basis))
 956         basis))))
 957
 958 (defun viper-key-to-emacs-key (key)
 959   (let (key-name char-p modifiers mod-char-list base-key base-key-name)
 960     (cond (viper-xemacs-p key)
 961
 962           ((symbolp key)
 963            (setq key-name (symbol-name key))
 964            (cond ((= (length key-name) 1) ; character event
 965                   (string-to-char key-name))
 966                  ;; Emacs doesn't recognize `return' and `escape' as events on
 967                  ;; dumb terminals, so we translate them into characters
 968                  ((and viper-emacs-p (not (viper-window-display-p))
 969                        (string= key-name "return"))
 970                   ?\C-m)
 971                  ((and viper-emacs-p (not (viper-window-display-p))
 972                        (string= key-name "escape"))
 973                   ?\e)
 974                  ;; pass symbol-event as is
 975                  (t key)))
 976
 977           ((listp key)
 978            (setq modifiers (subseq key 0 (1- (length key)))
 979                  base-key (viper-seq-last-elt key)
 980                  base-key-name (symbol-name base-key)
 981                  char-p (= (length base-key-name) 1))
 982            (setq mod-char-list
 983                  (mapcar
 984                   '(lambda (elt) (upcase (substring (symbol-name elt) 0 1)))
 985                   modifiers))
 986            (if char-p
 987                (setq key-name
 988                      (car (read-from-string
 989                            (concat
 990                             "?\\"
 991                             (mapconcat 'identity mod-char-list "-\\")
 992                             "-"
 993                             base-key-name))))
 994              (setq key-name
 995                    (intern
 996                     (concat
 997                      (mapconcat 'identity mod-char-list "-")
 998                      "-"
 999                      base-key-name))))))
1000     ))
1001
1002
1003 ;; Args can be a sequence of events, a string, or a Viper macro.  Will try to
1004 ;; convert events to keys and, if all keys are regular printable
1005 ;; characters, will return a string.  Otherwise, will return a string
1006 ;; representing a vector of converted events.  If the input was a Viper macro,
1007 ;; will return a string that represents this macro as a vector.
1008 (defun viper-array-to-string (event-seq)
1009   (let (temp temp2)
1010     (cond ((stringp event-seq) event-seq)
1011           ((viper-event-vector-p event-seq)
1012             (setq temp (mapcar 'viper-event-key event-seq))
1013             (cond ((viper-char-symbol-sequence-p temp)
1014                    (mapconcat 'symbol-name temp ""))
1015                   ((and (viper-char-array-p
1016                          (setq temp2 (mapcar 'viper-key-to-character temp))))
1017                    (mapconcat 'char-to-string temp2 ""))
1018                   (t (prin1-to-string (vconcat temp)))))
1019           ((viper-char-symbol-sequence-p event-seq)
1020            (mapconcat 'symbol-name event-seq ""))
1021           ((and (vectorp event-seq)
1022                 (viper-char-array-p
1023                  (setq temp (mapcar 'viper-key-to-character event-seq))))
1024            (mapconcat 'char-to-string temp ""))
1025           (t (prin1-to-string event-seq)))))
1026
1027 (defun viper-key-press-events-to-chars (events)
1028   (mapconcat (if viper-emacs-p
1029                  'char-to-string
1030                (lambda (elt) (char-to-string (event-to-character elt))))
1031              events
1032              ""))
1033
1034
1035 ;; Uses different timeouts for ESC-sequences and others
1036 (defsubst viper-fast-keysequence-p ()
1037   (not (viper-sit-for-short
1038         (if (viper-ESC-event-p last-input-event)
1039             viper-ESC-keyseq-timeout
1040           viper-fast-keyseq-timeout)
1041         t)))
1042
1043 (defun viper-read-char-exclusive ()
1044   (let (char
1045         (echo-keystrokes 1))
1046     (while (null char)
1047       (condition-case nil
1048           (setq char (read-char))
1049         (error
1050          ;; skip event if not char
1051          (viper-read-event))))
1052     char))
1053
1054 ;; key is supposed to be in viper's representation, e.g., (control l), a
1055 ;; character, etc.
1056 (defun viper-key-to-character (key)
1057   (cond ((eq key 'space) ?\ )
1058         ((eq key 'delete) ?\C-?)
1059         ((eq key 'return) ?\C-m)
1060         ((eq key 'backspace) ?\C-h)
1061         ((and (symbolp key)
1062               (= 1 (length (symbol-name key))))
1063          (string-to-char (symbol-name key)))
1064         ((and (listp key)
1065               (eq (car key) 'control)
1066               (symbol-name (nth 1 key))
1067               (= 1 (length (symbol-name (nth 1 key)))))
1068          (read (format "?\\C-%s" (symbol-name (nth 1 key)))))
1069         (t key)))
1070
1071
1072 (defun viper-setup-master-buffer (&rest other-files-or-buffers)
1073   "Set up the current buffer as a master buffer.
1074 Arguments become related buffers.  This function should normally be used in
1075 the `Local variables' section of a file."
1076   (setq viper-related-files-and-buffers-ring
1077         (make-ring (1+ (length other-files-or-buffers))))
1078   (mapcar '(lambda (elt)
1079              (viper-ring-insert viper-related-files-and-buffers-ring elt))
1080           other-files-or-buffers)
1081   (viper-ring-insert viper-related-files-and-buffers-ring (buffer-name))
1082   )
1083
1084 ;;; Movement utilities
1085
1086 ;; Characters that should not be considered as part of the word, in reformed-vi
1087 ;; syntax mode.
1088 (defconst viper-non-word-characters-reformed-vi
1089   "!@#$%^&*()-+=|\\~`{}[];:'\",<.>/?")
1090 ;; These are characters that are not to be considered as parts of a word in
1091 ;; Viper.
1092 ;; Set each time state changes and at loading time
1093 (viper-deflocalvar viper-non-word-characters  nil)
1094
1095 ;; must be buffer-local
1096 (viper-deflocalvar viper-ALPHA-char-class "w"
1097   "String of syntax classes characterizing Viper's alphanumeric symbols.
1098 In addition, the symbol `_' may be considered alphanumeric if
1099 `viper-syntax-preference' is `strict-vi' or `reformed-vi'.")
1100
1101 (defconst viper-strict-ALPHA-chars "a-zA-Z0-9_"
1102   "Regexp matching the set of alphanumeric characters acceptable to strict
1103 Vi.")
1104 (defconst viper-strict-SEP-chars " \t\n"
1105   "Regexp matching the set of alphanumeric characters acceptable to strict
1106 Vi.")
1107 (defconst viper-strict-SEP-chars-sans-newline " \t"
1108   "Regexp matching the set of alphanumeric characters acceptable to strict
1109 Vi.")
1110
1111 (defconst viper-SEP-char-class " -"
1112   "String of syntax classes for Vi separators.
1113 Usually contains ` ', linefeed, TAB or formfeed.")
1114
1115
1116 ;; Set Viper syntax classes and related variables according to
1117 ;; `viper-syntax-preference'.
1118 (defun viper-update-syntax-classes (&optional set-default)
1119   (let ((preference (cond ((eq viper-syntax-preference 'emacs)
1120                            "w")   ; Viper words have only Emacs word chars
1121                           ((eq viper-syntax-preference 'extended)
1122                            "w_")  ; Viper words have Emacs word & symbol chars
1123                           (t "w"))) ; Viper words are Emacs words plus `_'
1124         (non-word-chars (cond ((eq viper-syntax-preference 'reformed-vi)
1125                                (viper-string-to-list
1126                                 viper-non-word-characters-reformed-vi))
1127                               (t nil))))
1128     (if set-default
1129         (setq-default viper-ALPHA-char-class preference
1130                       viper-non-word-characters non-word-chars)
1131       (setq viper-ALPHA-char-class preference
1132             viper-non-word-characters non-word-chars))
1133     ))
1134
1135 ;; SYMBOL is used because customize requires it, but it is ignored, unless it
1136 ;; is `nil'.  If nil, use setq.
1137 (defun viper-set-syntax-preference (&optional symbol value)
1138   "Set Viper syntax preference.
1139 If called interactively or if SYMBOL is nil, sets syntax preference in current
1140 buffer.  If called non-interactively, preferably via the customization widget,
1141 sets the default value."
1142   (interactive)
1143   (or value
1144       (setq value
1145             (completing-read
1146              "Viper syntax preference: "
1147              '(("strict-vi") ("reformed-vi") ("extended") ("emacs"))
1148              nil 'require-match)))
1149   (if (stringp value) (setq value (intern value)))
1150   (or (memq value '(strict-vi reformed-vi extended emacs))
1151       (error "Invalid Viper syntax preference, %S" value))
1152   (if symbol
1153       (setq-default viper-syntax-preference value)
1154     (setq viper-syntax-preference value))
1155   (viper-update-syntax-classes))
1156
1157 (defcustom viper-syntax-preference 'reformed-vi
1158   "*Syntax type characterizing Viper's alphanumeric symbols.
1159 Affects movement and change commands that deal with Vi-style words.
1160 Works best when set in the hooks to various major modes.
1161
1162 `strict-vi' means Viper words are (hopefully) exactly as in Vi.
1163
1164 `reformed-vi' means Viper words are like Emacs words \(as determined using
1165 Emacs syntax tables, which are different for different major modes\) with two
1166 exceptions: the symbol `_' is always part of a word and typical Vi non-word
1167 symbols, such as `,',:,\",),{, etc., are excluded.
1168 This behaves very close to `strict-vi', but also works well with non-ASCII
1169 characters from various alphabets.
1170
1171 `extended' means Viper word constituents are symbols that are marked as being
1172 parts of words OR symbols in Emacs syntax tables.
1173 This is most appropriate for major modes intended for editing programs.
1174
1175 `emacs' means Viper words are the same as Emacs words as specified by Emacs
1176 syntax tables.
1177 This option is appropriate if you like Emacs-style words."
1178   :type '(radio (const strict-vi) (const reformed-vi)
1179                  (const extended) (const emacs))
1180   :set 'viper-set-syntax-preference
1181   :group 'viper)
1182 (make-variable-buffer-local 'viper-syntax-preference)
1183
1184
1185 ;; addl-chars are characters to be temporarily considered as alphanumerical
1186 (defun viper-looking-at-alpha (&optional addl-chars)
1187   (or (stringp addl-chars) (setq addl-chars ""))
1188   (if (eq viper-syntax-preference 'reformed-vi)
1189       (setq addl-chars (concat addl-chars "_")))
1190   (let ((char (char-after (point))))
1191     (if char
1192         (if (eq viper-syntax-preference 'strict-vi)
1193             (looking-at (concat "[" viper-strict-ALPHA-chars addl-chars "]"))
1194           (or
1195            ;; or one of the additional chars being asked to include
1196            (memq char (viper-string-to-list addl-chars))
1197            (and
1198             ;; not one of the excluded word chars
1199             (not (memq char viper-non-word-characters))
1200             ;; char of the Viper-word syntax class
1201             (memq (char-syntax char)
1202                   (viper-string-to-list viper-ALPHA-char-class))))))
1203     ))
1204
1205 (defun viper-looking-at-separator ()
1206   (let ((char (char-after (point))))
1207     (if char
1208         (if (eq viper-syntax-preference 'strict-vi)
1209             (memq char (viper-string-to-list viper-strict-SEP-chars))
1210           (or (eq char ?\n) ; RET is always a separator in Vi
1211               (memq (char-syntax char)
1212                     (viper-string-to-list viper-SEP-char-class)))))
1213     ))
1214
1215 (defsubst viper-looking-at-alphasep (&optional addl-chars)
1216   (or (viper-looking-at-separator) (viper-looking-at-alpha addl-chars)))
1217
1218 (defun viper-skip-alpha-forward (&optional addl-chars)
1219   (or (stringp addl-chars) (setq addl-chars ""))
1220   (viper-skip-syntax
1221    'forward
1222    (cond ((eq viper-syntax-preference 'strict-vi)
1223           "")
1224          (t viper-ALPHA-char-class))
1225    (cond ((eq viper-syntax-preference 'strict-vi)
1226           (concat viper-strict-ALPHA-chars addl-chars))
1227          (t addl-chars))))
1228
1229 (defun viper-skip-alpha-backward (&optional addl-chars)
1230   (or (stringp addl-chars) (setq addl-chars ""))
1231   (viper-skip-syntax
1232    'backward
1233    (cond ((eq viper-syntax-preference 'strict-vi)
1234           "")
1235          (t viper-ALPHA-char-class))
1236    (cond ((eq viper-syntax-preference 'strict-vi)
1237           (concat viper-strict-ALPHA-chars addl-chars))
1238          (t addl-chars))))
1239
1240 ;; weird syntax tables may confuse strict-vi style
1241 (defsubst viper-skip-all-separators-forward (&optional within-line)
1242   (if (eq viper-syntax-preference 'strict-vi)
1243       (if within-line
1244           (skip-chars-forward viper-strict-SEP-chars-sans-newline)
1245         (skip-chars-forward viper-strict-SEP-chars))
1246     (viper-skip-syntax 'forward
1247                        viper-SEP-char-class
1248                        (or within-line "\n")
1249                        (if within-line (viper-line-pos 'end)))))
1250 (defsubst viper-skip-all-separators-backward (&optional within-line)
1251   (if (eq viper-syntax-preference 'strict-vi)
1252       (if within-line
1253           (skip-chars-backward viper-strict-SEP-chars-sans-newline)
1254         (skip-chars-backward viper-strict-SEP-chars))
1255     (viper-skip-syntax 'backward
1256                        viper-SEP-char-class
1257                        (or within-line "\n")
1258                        (if within-line (viper-line-pos 'start)))))
1259 (defun viper-skip-nonseparators (direction)
1260   (viper-skip-syntax
1261    direction
1262    (concat "^" viper-SEP-char-class)
1263    nil
1264    (viper-line-pos (if (eq direction 'forward) 'end 'start))))
1265
1266
1267 ;; skip over non-word constituents and non-separators
1268 (defun viper-skip-nonalphasep-forward ()
1269   (if (eq viper-syntax-preference 'strict-vi)
1270       (skip-chars-forward
1271        (concat "^" viper-strict-SEP-chars viper-strict-ALPHA-chars))
1272     (viper-skip-syntax
1273      'forward
1274      (concat "^" viper-ALPHA-char-class viper-SEP-char-class)
1275      ;; Emacs may consider some of these as words, but we don't want them
1276      viper-non-word-characters
1277      (viper-line-pos 'end))))
1278 (defun viper-skip-nonalphasep-backward ()
1279   (if (eq viper-syntax-preference 'strict-vi)
1280       (skip-chars-backward
1281        (concat "^" viper-strict-SEP-chars viper-strict-ALPHA-chars))
1282     (viper-skip-syntax
1283      'backward
1284      (concat "^" viper-ALPHA-char-class viper-SEP-char-class)
1285      ;; Emacs may consider some of these as words, but we don't want them
1286      viper-non-word-characters
1287      (viper-line-pos 'start))))
1288
1289 ;; Skip SYNTAX like skip-syntax-* and ADDL-CHARS like skip-chars-*
1290 ;; Return the number of chars traveled.
1291 ;; Both SYNTAX or ADDL-CHARS can be strings or lists of characters.
1292 ;; When SYNTAX is "w", then viper-non-word-characters are not considered to be
1293 ;; words, even if Emacs syntax table says they are.
1294 (defun viper-skip-syntax (direction syntax addl-chars &optional limit)
1295   (let ((total 0)
1296         (local 1)
1297         (skip-chars-func
1298          (if (eq direction 'forward)
1299              'skip-chars-forward 'skip-chars-backward))
1300         (skip-syntax-func
1301          (if (eq direction 'forward)
1302              'viper-forward-char-carefully 'viper-backward-char-carefully))
1303         char-looked-at syntax-of-char-looked-at negated-syntax)
1304     (setq addl-chars
1305           (cond ((listp addl-chars) (viper-charlist-to-string addl-chars))
1306                 ((stringp addl-chars) addl-chars)
1307                 (t "")))
1308     (setq syntax
1309           (cond ((listp syntax) syntax)
1310                 ((stringp syntax) (viper-string-to-list syntax))
1311                 (t nil)))
1312     (if (memq ?^ syntax) (setq negated-syntax t))
1313
1314     (while (and (not (= local 0))
1315                 (cond ((eq direction 'forward)
1316                        (not (eobp)))
1317                       (t (not (bobp)))))
1318       (setq char-looked-at (viper-char-at-pos direction)
1319             ;; if outside the range, set to nil
1320             syntax-of-char-looked-at (if char-looked-at
1321                                          (char-syntax char-looked-at)))
1322       (setq local
1323             (+ (if (and
1324                     (cond ((and limit (eq direction 'forward))
1325                            (< (point) limit))
1326                           (limit ; backward & limit
1327                            (> (point) limit))
1328                           (t t)) ; no limit
1329                     ;; char under/before cursor has appropriate syntax
1330                     (if negated-syntax
1331                         (not (memq syntax-of-char-looked-at syntax))
1332                       (memq syntax-of-char-looked-at syntax))
1333                     ;; if char-syntax class is "word", make sure it is not one
1334                     ;; of the excluded characters
1335                     (if (and (eq syntax-of-char-looked-at ?w)
1336                              (not negated-syntax))
1337                         (not (memq char-looked-at viper-non-word-characters))
1338                       t))
1339                    (funcall skip-syntax-func 1)
1340                  0)
1341                (funcall skip-chars-func addl-chars limit)))
1342       (setq total (+ total local)))
1343     total
1344     ))
1345
1346
1347
1348 (provide 'viper-util)
1349
1350
1351 ;;; Local Variables:
1352 ;;; eval: (put 'viper-deflocalvar 'lisp-indent-hook 'defun)
1353 ;;; End:
1354
1355 ;;;  viper-util.el ends here