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+ − 1 ;;; ehelp.el --- bindings for electric-help mode
+ − 2
+ − 3 ;; Copyright (C) 1986, 1995 Free Software Foundation, Inc.
+ − 4
+ − 5 ;; Author: Richard Mlynarik <mly@ai.mit.edu>
+ − 6 ;; Maintainer: FSF
+ − 7 ;; Keywords: help, extensions
+ − 8
+ − 9 ;; This file is part of XEmacs.
+ − 10
+ − 11 ;; XEmacs is free software; you can redistribute it and/or modify it
+ − 12 ;; 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 ;; XEmacs is distributed in the hope that it will be useful, but
+ − 17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
+ − 18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ − 19 ;; General Public License for more details.
+ − 20
+ − 21 ;; You should have received a copy of the GNU General Public License
+ − 22 ;; along with XEmacs; see the file COPYING. If not, write to the Free
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+ − 23 ;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ − 24 ;; 02111-1307, USA.
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+ − 25
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+ − 26 ;;; Synched up with: FSF 19.34.
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+ − 27
+ − 28 ;;; Commentary:
+ − 29
+ − 30 ;; This package provides a pre-packaged `Electric Help Mode' for
+ − 31 ;; browsing on-line help screens. There is one entry point,
+ − 32 ;; `with-electric-help'; all you have to give it is a no-argument
+ − 33 ;; function that generates the actual text of the help into the current
+ − 34 ;; buffer.
+ − 35
+ − 36 ;; To make this the default, you must do
+ − 37 ;; (require 'ehelp)
+ − 38 ;; (define-key global-map "\C-h" 'ehelp-command)
+ − 39 ;; (define-key global-map [help] 'ehelp-command)
+ − 40 ;; (define-key global-map [f1] 'ehelp-command)
+ − 41
+ − 42 ;;; Code:
+ − 43
+ − 44 (require 'electric)
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+ − 45 (defvar electric-help-map ()
+ − 46 "Keymap defining commands available in `electric-help-mode'.")
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+ − 47
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+ − 48 (defvar electric-help-form-to-execute nil)
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+ − 49
+ − 50 (put 'electric-help-undefined 'suppress-keymap t)
+ − 51 (if electric-help-map
+ − 52 ()
+ − 53 (let ((map (make-keymap)))
+ − 54 ;; allow all non-self-inserting keys - search, scroll, etc, but
+ − 55 ;; let M-x and C-x exit ehelp mode and retain buffer:
+ − 56 (suppress-keymap map)
+ − 57 (define-key map "\C-u" 'electric-help-undefined)
+ − 58 (define-key map [(control ?0)] 'electric-help-undefined)
+ − 59 (define-key map [(control ?1)] 'electric-help-undefined)
+ − 60 (define-key map [(control ?2)] 'electric-help-undefined)
+ − 61 (define-key map [(control ?3)] 'electric-help-undefined)
+ − 62 (define-key map [(control ?4)] 'electric-help-undefined)
+ − 63 (define-key map [(control ?5)] 'electric-help-undefined)
+ − 64 (define-key map [(control ?6)] 'electric-help-undefined)
+ − 65 (define-key map [(control ?7)] 'electric-help-undefined)
+ − 66 (define-key map [(control ?8)] 'electric-help-undefined)
+ − 67 (define-key map [(control ?9)] 'electric-help-undefined)
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+ − 68 (define-key map (vector help-char) 'electric-help-help)
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+ − 69 (define-key map "?" 'electric-help-help)
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+ − 70 ;; XEmacs addition
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+ − 71 (define-key map 'help 'electric-help-help)
+ − 72 (define-key map " " 'scroll-up)
+ − 73 (define-key map "\^?" 'scroll-down)
+ − 74 (define-key map "." 'beginning-of-buffer)
+ − 75 (define-key map "<" 'beginning-of-buffer)
+ − 76 (define-key map ">" 'end-of-buffer)
+ − 77 ;(define-key map "\C-g" 'electric-help-exit)
+ − 78 (define-key map "q" 'electric-help-exit)
+ − 79 (define-key map "Q" 'electric-help-exit)
+ − 80 ;;a better key than this?
+ − 81 (define-key map "r" 'electric-help-retain)
+ − 82 (define-key map "R" 'electric-help-retain)
+ − 83 (define-key map "\ex" 'electric-help-execute-extended)
+ − 84 (define-key map "\C-x" 'electric-help-ctrl-x-prefix)
+ − 85
+ − 86 (setq electric-help-map map)))
+ − 87
+ − 88 (defun electric-help-mode ()
+ − 89 "`with-electric-help' temporarily places its buffer in this mode.
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+ − 90 \(On exit from `with-electric-help', the buffer is put in `default-major-mode'.)"
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+ − 91 (setq buffer-read-only t)
+ − 92 (setq mode-name "Help")
+ − 93 (setq major-mode 'help)
+ − 94 (setq modeline-buffer-identification '(" Help: %b"))
+ − 95 (use-local-map electric-help-map)
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+ − 96 (add-hook 'mouse-leave-buffer-hook 'electric-help-retain)
+ − 97 (view-mode -1)
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+ − 98 ;; this is done below in with-electric-help
+ − 99 ;(run-hooks 'electric-help-mode-hook)
+ − 100 )
+ − 101
+ − 102 ;;;###autoload
+ − 103 (defun with-electric-help (thunk &optional buffer noerase minheight)
+ − 104 "Pop up an \"electric\" help buffer.
+ − 105 The arguments are THUNK &optional BUFFER NOERASE MINHEIGHT.
+ − 106 THUNK is a function of no arguments which is called to initialize the
+ − 107 contents of BUFFER. BUFFER defaults to `*Help*'. BUFFER will be
+ − 108 erased before THUNK is called unless NOERASE is non-nil. THUNK will
+ − 109 be called while BUFFER is current and with `standard-output' bound to
+ − 110 the buffer specified by BUFFER.
+ − 111
+ − 112 If THUNK returns nil, we display BUFFER starting at the top, and
+ − 113 shrink the window to fit. If THUNK returns non-nil, we don't do those things.
+ − 114
+ − 115 After THUNK has been called, this function \"electrically\" pops up a window
+ − 116 in which BUFFER is displayed and allows the user to scroll through that buffer
+ − 117 in electric-help-mode. The window's height will be at least MINHEIGHT if
+ − 118 this value is non-nil.
+ − 119
+ − 120 If THUNK returns nil, we display BUFFER starting at the top, and
+ − 121 shrink the window to fit. If THUNK returns non-nil, we don't do those
+ − 122 things.
+ − 123
+ − 124 When the user exits (with `electric-help-exit', or otherwise) the help
+ − 125 buffer's window disappears (i.e., we use `save-window-excursion')
+ − 126 BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
+ − 127 (setq buffer (get-buffer-create (or buffer "*Help*")))
+ − 128 (let ((one (one-window-p t))
+ − 129 (config (current-window-configuration))
+ − 130 (bury nil)
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+ − 131 (electric-help-form-to-execute nil))
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+ − 132 (unwind-protect
+ − 133 (save-excursion
+ − 134 (if one (goto-char (window-start (selected-window))))
+ − 135 (let ((pop-up-windows t))
+ − 136 (pop-to-buffer buffer))
+ − 137 (save-excursion
+ − 138 (set-buffer buffer)
+ − 139 (if (and minheight (< (window-height) minheight))
+ − 140 (enlarge-window (- minheight (window-height))))
+ − 141 (electric-help-mode)
+ − 142 (setq buffer-read-only nil)
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+ − 143 (or noerase
+ − 144 (erase-buffer)))
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+ − 145 (let ((standard-output buffer))
+ − 146 (if (not (funcall thunk))
+ − 147 (progn
+ − 148 (set-buffer buffer)
+ − 149 (set-buffer-modified-p nil)
+ − 150 (goto-char (point-min))
+ − 151 (if one (shrink-window-if-larger-than-buffer (selected-window))))))
+ − 152 (set-buffer buffer)
+ − 153 (run-hooks 'electric-help-mode-hook)
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+ − 154 (setq buffer-read-only t)
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+ − 155 (if (eq (car-safe
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+ − 156 ;; XEmacs: Don't be screwed by minor-modes (view-minor-mode)
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+ − 157 (let ((overriding-local-map electric-help-map))
+ − 158 (electric-help-command-loop)))
+ − 159 'retain)
+ − 160 (setq config (current-window-configuration))
+ − 161 (setq bury t)))
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+ − 162 (message "")
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+ − 163 (set-buffer buffer)
+ − 164 (setq buffer-read-only nil)
+ − 165 (condition-case ()
+ − 166 (funcall (or default-major-mode 'fundamental-mode))
+ − 167 (error nil))
+ − 168 (set-window-configuration config)
+ − 169 (if bury
+ − 170 (progn
+ − 171 ;;>> Perhaps this shouldn't be done.
+ − 172 ;; so that when we say "Press space to bury" we mean it
+ − 173 (replace-buffer-in-windows buffer)
+ − 174 ;; must do this outside of save-window-excursion
+ − 175 (bury-buffer buffer)))
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+ − 176 (eval electric-help-form-to-execute))))
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+ − 177
+ − 178 (defun electric-help-command-loop ()
+ − 179 (catch 'exit
+ − 180 (if (pos-visible-in-window-p (point-max))
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+ − 181 (progn (message "%s" (substitute-command-keys "<<< Press Space to bury the help buffer, Press \\[electric-help-retain] to retain it >>>"))
+ − 182 ;; XEmacs change
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+ − 183 (if (equal (setq unread-command-events
+ − 184 (list (next-command-event)))
+ − 185 '(?\ ))
+ − 186 (progn (setq unread-command-events nil)
+ − 187 (throw 'exit t)))))
+ − 188 (let (up down both neither
+ − 189 (standard (and (eq (key-binding " ")
+ − 190 'scroll-up)
+ − 191 (eq (key-binding "\^?")
+ − 192 'scroll-down)
+ − 193 (eq (key-binding "q")
+ − 194 'electric-help-exit)
+ − 195 (eq (key-binding "r")
+ − 196 'electric-help-retain))))
+ − 197 (Electric-command-loop
+ − 198 'exit
+ − 199 (function (lambda ()
+ − 200 (sit-for 0) ;necessary if last command was end-of-buffer or
+ − 201 ;beginning-of-buffer - otherwise pos-visible-in-window-p
+ − 202 ;will yield a wrong result.
+ − 203 (let ((min (pos-visible-in-window-p (point-min)))
+ − 204 (max (pos-visible-in-window-p (point-max))))
+ − 205 (cond (isearch-mode 'noprompt)
+ − 206 ((and min max)
+ − 207 (cond (standard "Press q to exit, r to retain ")
+ − 208 (neither)
+ − 209 (t (setq neither (substitute-command-keys "Press \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
+ − 210 (min
+ − 211 (cond (standard "Press SPC to scroll, q to exit, r to retain ")
+ − 212 (up)
+ − 213 (t (setq up (substitute-command-keys "Press \\[scroll-up] to scroll, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
+ − 214 (max
+ − 215 (cond (standard "Press DEL to scroll back, q to exit, r to retain ")
+ − 216 (down)
+ − 217 (t (setq down (substitute-command-keys "Press \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
+ − 218 (t
+ − 219 (cond (standard "Press SPC to scroll, DEL to scroll back, q to exit, r to retain ")
+ − 220 (both)
+ − 221 (t (setq both (substitute-command-keys "Press \\[scroll-up] to scroll, \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))))))
+ − 222 t))))
+ − 223
+ − 224
+ − 225
+ − 226 ;(defun electric-help-scroll-up (arg)
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+ − 227 ; ">>>Doc"
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+ − 228 ; (interactive "P")
+ − 229 ; (if (and (null arg) (pos-visible-in-window-p (point-max)))
+ − 230 ; (electric-help-exit)
+ − 231 ; (scroll-up arg)))
+ − 232
+ − 233 (defun electric-help-exit ()
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+ − 234 ">>>Doc"
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+ − 235 (interactive)
+ − 236 (throw 'exit t))
+ − 237
+ − 238 (defun electric-help-retain ()
+ − 239 "Exit `electric-help', retaining the current window/buffer configuration.
+ − 240 \(The *Help* buffer will not be selected, but \\[switch-to-buffer-other-window] RET
+ − 241 will select it.)"
+ − 242 (interactive)
+ − 243 ;; Make sure that we don't throw twice, even if two events cause
+ − 244 ;; calling this function:
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+ − 245 (if (memq 'electric-help-retain mouse-leave-buffer-hook)
+ − 246 (progn
+ − 247 (remove-hook 'mouse-leave-buffer-hook 'electric-help-retain)
+ − 248 (throw 'exit '(retain)))))
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+ − 249
+ − 250
+ − 251 (defun electric-help-undefined ()
+ − 252 (interactive)
+ − 253 (error "%s is undefined -- Press %s to exit"
+ − 254 (mapconcat 'single-key-description (this-command-keys) " ")
+ − 255 (if (eq (key-binding "q") 'electric-help-exit)
+ − 256 "q"
+ − 257 (substitute-command-keys "\\[electric-help-exit]"))))
+ − 258
+ − 259
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+ − 260 ;>>> this needs to be hairified (recursive help, anybody?)
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+ − 261 (defun electric-help-help ()
+ − 262 (interactive)
+ − 263 (if (and (eq (key-binding "q") 'electric-help-exit)
+ − 264 (eq (key-binding " ") 'scroll-up)
+ − 265 (eq (key-binding "\^?") 'scroll-down)
+ − 266 (eq (key-binding "r") 'electric-help-retain))
+ − 267 (message "SPC scrolls up, DEL scrolls down, q exits burying help buffer, r exits")
+ − 268 (message "%s" (substitute-command-keys "\\[scroll-up] scrolls up, \\[scroll-down] scrolls down, \\[electric-help-exit] exits burying help buffer, \\[electric-help-retain] exits")))
+ − 269 (sit-for 2))
+ − 270
+ − 271
+ − 272 ;;;###autoload
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+ − 273 (defun electric-helpify (fun &optional name)
+ − 274 (let ((name (or name "*Help*")))
+ − 275 (if (save-window-excursion
+ − 276 ;; kludge-o-rama
+ − 277 (let* ((p (symbol-function 'print-help-return-message))
+ − 278 (b (get-buffer name))
+ − 279 (m (buffer-modified-p b)))
+ − 280 (and b (not (get-buffer-window b))
+ − 281 (setq b nil))
+ − 282 (unwind-protect
+ − 283 (progn
+ − 284 (message "%s..." (capitalize (symbol-name fun)))
+ − 285 ;; with-output-to-temp-buffer marks the buffer as unmodified.
+ − 286 ;; kludging excessively and relying on that as some sort
+ − 287 ;; of indication leads to the following abomination...
+ − 288 ;;>> This would be doable without such icky kludges if either
+ − 289 ;;>> (a) there were a function to read the interactive
+ − 290 ;;>> args for a command and return a list of those args.
+ − 291 ;;>> (To which one would then just apply the command)
+ − 292 ;;>> (The only problem with this is that interactive-p
+ − 293 ;;>> would break, but that is such a misfeature in
+ − 294 ;;>> any case that I don't care)
+ − 295 ;;>> It is easy to do this for emacs-lisp functions;
+ − 296 ;;>> the only problem is getting the interactive spec
+ − 297 ;;>> for subrs
+ − 298 ;;>> (b) there were a function which returned a
+ − 299 ;;>> modification-tick for a buffer. One could tell
+ − 300 ;;>> whether a buffer had changed by whether the
+ − 301 ;;>> modification-tick were different.
+ − 302 ;;>> (Presumably there would have to be a way to either
+ − 303 ;;>> restore the tick to some previous value, or to
+ − 304 ;;>> suspend updating of the tick in order to allow
+ − 305 ;;>> things like momentary-string-display)
+ − 306 (and b
+ − 307 (save-excursion
+ − 308 (set-buffer b)
+ − 309 (set-buffer-modified-p t)))
+ − 310 (fset 'print-help-return-message 'ignore)
+ − 311 (call-interactively fun)
+ − 312 (and (get-buffer name)
+ − 313 (get-buffer-window (get-buffer name))
+ − 314 (or (not b)
+ − 315 (not (eq b (get-buffer name)))
+ − 316 (not (buffer-modified-p b)))))
+ − 317 (fset 'print-help-return-message p)
+ − 318 (and b (buffer-name b)
+ − 319 (save-excursion
+ − 320 (set-buffer b)
+ − 321 (set-buffer-modified-p m))))))
+ − 322 (with-electric-help 'ignore name t))))
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+ − 323
+ − 324
+ − 325
+ − 326 ;; This is to be bound to M-x in ehelp mode. Retains ehelp buffer and then
+ − 327 ;; continues with execute-extended-command.
+ − 328 (defun electric-help-execute-extended (prefixarg)
+ − 329 (interactive "p")
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+ − 330 (setq electric-help-form-to-execute '(execute-extended-command nil))
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+ − 331 (electric-help-retain))
+ − 332
+ − 333 ;; This is to be buond to C-x in ehelp mode. Retains ehelp buffer and then
+ − 334 ;; continues with ctrl-x prefix.
+ − 335 (defun electric-help-ctrl-x-prefix (prefixarg)
+ − 336 (interactive "p")
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+ − 337 (setq electric-help-form-to-execute '(progn (message nil) (setq unread-command-char ?\C-x)))
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+ − 338 (electric-help-retain))
+ − 339
+ − 340
+ − 341 (defun electric-describe-key ()
+ − 342 (interactive)
+ − 343 (electric-helpify 'describe-key))
+ − 344
+ − 345 (defun electric-describe-mode ()
+ − 346 (interactive)
+ − 347 (electric-helpify 'describe-mode))
+ − 348
+ − 349 (defun electric-view-lossage ()
+ − 350 (interactive)
+ − 351 (electric-helpify 'view-lossage))
+ − 352
+ − 353 ;(defun electric-help-for-help ()
+ − 354 ; "See help-for-help"
+ − 355 ; (interactive)
+ − 356 ; )
+ − 357
+ − 358 (defun electric-describe-function ()
+ − 359 (interactive)
+ − 360 (electric-helpify 'describe-function))
+ − 361
+ − 362 (defun electric-describe-variable ()
+ − 363 (interactive)
+ − 364 (electric-helpify 'describe-variable))
+ − 365
+ − 366 (defun electric-describe-bindings ()
+ − 367 (interactive)
+ − 368 (electric-helpify 'describe-bindings))
+ − 369
+ − 370 (defun electric-describe-syntax ()
+ − 371 (interactive)
+ − 372 (electric-helpify 'describe-syntax))
+ − 373
+ − 374 (defun electric-command-apropos ()
+ − 375 (interactive)
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+ − 376 (electric-helpify 'command-apropos "*Apropos*"))
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+ − 377
+ − 378 ;(define-key help-map "a" 'electric-command-apropos)
+ − 379
+ − 380 (defun electric-apropos ()
+ − 381 (interactive)
+ − 382 (electric-helpify 'apropos))
+ − 383
+ − 384
+ − 385 ;;;; ehelp-map
+ − 386
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+ − 387 (defvar ehelp-map ())
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+ − 388 (if ehelp-map
+ − 389 nil
+ − 390 ;; #### WTF? Why don't we just use substitute-key-definition
+ − 391 ;; like FSF does?
+ − 392 (let ((shadow '((apropos . electric-apropos)
+ − 393 (command-apropos . electric-command-apropos)
+ − 394 (describe-key . electric-describe-key)
+ − 395 (describe-mode . electric-describe-mode)
+ − 396 (view-lossage . electric-view-lossage)
+ − 397 (describe-function . electric-describe-function)
+ − 398 (describe-variable . electric-describe-variable)
+ − 399 (describe-bindings . electric-describe-bindings)
+ − 400 (describe-syntax . electric-describe-syntax)))
+ − 401 (map (make-sparse-keymap)))
+ − 402 (set-keymap-name map 'ehelp-map)
+ − 403 (set-keymap-parents map (list help-map))
+ − 404 ;; Shadow bindings which would be inherited from help-map
+ − 405 ;;#### This doesn't descend into sub-keymaps
+ − 406 (map-keymap (function (lambda (key binding)
+ − 407 (let ((tem (assq binding shadow)))
+ − 408 (if tem
+ − 409 (define-key map key (cdr tem))))))
+ − 410 help-map)
+ − 411 (setq ehelp-map map)
+ − 412 (fset 'ehelp-command map)))
+ − 413
+ − 414 ;; Do (define-key global-map "\C-h" 'ehelp-command) if you want to win
+ − 415
+ − 416 (provide 'ehelp)
+ − 417
+ − 418 ;;; ehelp.el ends here
