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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>
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+ − 6
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+ − 7 ;; Maintainer: FSF
+ − 8 ;; Keywords: help, extensions
+ − 9
+ − 10 ;; This file is part of XEmacs.
+ − 11
+ − 12 ;; XEmacs is free software; you can redistribute it and/or modify it
+ − 13 ;; under the terms of the GNU General Public License as published by
+ − 14 ;; the Free Software Foundation; either version 2, or (at your option)
+ − 15 ;; any later version.
+ − 16
+ − 17 ;; XEmacs is distributed in the hope that it will be useful, but
+ − 18 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
+ − 19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ − 20 ;; General Public License for more details.
+ − 21
+ − 22 ;; You should have received a copy of the GNU General Public License
+ − 23 ;; along with XEmacs; see the file COPYING. If not, write to the Free
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+ − 24 ;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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+ − 25
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+ − 26 ;;; Synched up with: FSF 19.30.
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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
+ − 46 (defvar electric-help-map nil
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+ − 47 "Keymap defining commands available in `electric-help-mode'.")
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+ − 48
+ − 49 (put 'electric-help-undefined 'suppress-keymap t)
+ − 50 (if electric-help-map
+ − 51 ()
+ − 52 (let ((map (make-keymap)))
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+ − 53 (set-keymap-name map 'electric-help-map)
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+ − 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)
+ − 68 (define-key map (char-to-string help-char) 'electric-help-help)
+ − 69 (define-key map "?" 'electric-help-help)
+ − 70 (define-key map 'help 'electric-help-help)
+ − 71 (define-key map " " 'scroll-up)
+ − 72 (define-key map "\^?" 'scroll-down)
+ − 73 (define-key map "." 'beginning-of-buffer)
+ − 74 (define-key map "<" 'beginning-of-buffer)
+ − 75 (define-key map ">" 'end-of-buffer)
+ − 76 ;(define-key map "\C-g" 'electric-help-exit)
+ − 77 (define-key map "q" 'electric-help-exit)
+ − 78 (define-key map "Q" 'electric-help-exit)
+ − 79 ;;a better key than this?
+ − 80 (define-key map "r" 'electric-help-retain)
+ − 81 (define-key map "R" 'electric-help-retain)
+ − 82 (define-key map "\ex" 'electric-help-execute-extended)
+ − 83 (define-key map "\C-x" 'electric-help-ctrl-x-prefix)
+ − 84
+ − 85 (setq electric-help-map map)))
+ − 86
+ − 87 (defun electric-help-mode ()
+ − 88 "`with-electric-help' temporarily places its buffer in this mode.
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+ − 89 \(On exit from `with-electric-help', the buffer is put in `default-major-mode'.\)"
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+ − 90 (setq buffer-read-only t)
+ − 91 (setq mode-name "Help")
+ − 92 (setq major-mode 'help)
+ − 93 (setq modeline-buffer-identification '(" Help: %b"))
+ − 94 (use-local-map electric-help-map)
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+ − 95 (setq mouse-leave-buffer-hook '(electric-help-retain))
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+ − 96 ;; this is done below in with-electric-help
+ − 97 ;(run-hooks 'electric-help-mode-hook)
+ − 98 )
+ − 99
+ − 100 ;;;###autoload
+ − 101 (defun with-electric-help (thunk &optional buffer noerase minheight)
+ − 102 "Pop up an \"electric\" help buffer.
+ − 103 The arguments are THUNK &optional BUFFER NOERASE MINHEIGHT.
+ − 104 THUNK is a function of no arguments which is called to initialize the
+ − 105 contents of BUFFER. BUFFER defaults to `*Help*'. BUFFER will be
+ − 106 erased before THUNK is called unless NOERASE is non-nil. THUNK will
+ − 107 be called while BUFFER is current and with `standard-output' bound to
+ − 108 the buffer specified by BUFFER.
+ − 109
+ − 110 If THUNK returns nil, we display BUFFER starting at the top, and
+ − 111 shrink the window to fit. If THUNK returns non-nil, we don't do those things.
+ − 112
+ − 113 After THUNK has been called, this function \"electrically\" pops up a window
+ − 114 in which BUFFER is displayed and allows the user to scroll through that buffer
+ − 115 in electric-help-mode. The window's height will be at least MINHEIGHT if
+ − 116 this value is non-nil.
+ − 117
+ − 118 If THUNK returns nil, we display BUFFER starting at the top, and
+ − 119 shrink the window to fit. If THUNK returns non-nil, we don't do those
+ − 120 things.
+ − 121
+ − 122 When the user exits (with `electric-help-exit', or otherwise) the help
+ − 123 buffer's window disappears (i.e., we use `save-window-excursion')
+ − 124 BUFFER is put into `default-major-mode' (or `fundamental-mode') when we exit."
+ − 125 (setq buffer (get-buffer-create (or buffer "*Help*")))
+ − 126 (let ((one (one-window-p t))
+ − 127 (config (current-window-configuration))
+ − 128 (bury nil)
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+ − 129 (to-be-executed nil))
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+ − 130 (unwind-protect
+ − 131 (save-excursion
+ − 132 (if one (goto-char (window-start (selected-window))))
+ − 133 (let ((pop-up-windows t))
+ − 134 (pop-to-buffer buffer))
+ − 135 (save-excursion
+ − 136 (set-buffer buffer)
+ − 137 (if (and minheight (< (window-height) minheight))
+ − 138 (enlarge-window (- minheight (window-height))))
+ − 139 (electric-help-mode)
+ − 140 (setq buffer-read-only nil)
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+ − 141 (or noerase (erase-buffer)))
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+ − 142 (let ((standard-output buffer))
+ − 143 (if (not (funcall thunk))
+ − 144 (progn
+ − 145 (set-buffer buffer)
+ − 146 (set-buffer-modified-p nil)
+ − 147 (goto-char (point-min))
+ − 148 (if one (shrink-window-if-larger-than-buffer (selected-window))))))
+ − 149 (set-buffer buffer)
+ − 150 (run-hooks 'electric-help-mode-hook)
+ − 151 (if (eq (car-safe
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+ − 152 ;; Don't be screwed by minor-modes (view-minor-mode)
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+ − 153 (let ((overriding-local-map electric-help-map))
+ − 154 (electric-help-command-loop)))
+ − 155 'retain)
+ − 156 (setq config (current-window-configuration))
+ − 157 (setq bury t)))
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+ − 158 (message nil)
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+ − 159 (set-buffer buffer)
+ − 160 (setq buffer-read-only nil)
+ − 161 (condition-case ()
+ − 162 (funcall (or default-major-mode 'fundamental-mode))
+ − 163 (error nil))
+ − 164 (set-window-configuration config)
+ − 165 (if bury
+ − 166 (progn
+ − 167 ;;>> Perhaps this shouldn't be done.
+ − 168 ;; so that when we say "Press space to bury" we mean it
+ − 169 (replace-buffer-in-windows buffer)
+ − 170 ;; must do this outside of save-window-excursion
+ − 171 (bury-buffer buffer)))
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+ − 172 (eval to-be-executed))))
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+ − 173
+ − 174 (defun electric-help-command-loop ()
+ − 175 (catch 'exit
+ − 176 (if (pos-visible-in-window-p (point-max))
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+ − 177 (progn (message (substitute-command-keys "<<< Press Space to bury the help buffer, Press \\[electric-help-retain] to retain it >>>"))
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+ − 178 (if (equal (setq unread-command-events
+ − 179 (list (next-command-event)))
+ − 180 '(?\ ))
+ − 181 (progn (setq unread-command-events nil)
+ − 182 (throw 'exit t)))))
+ − 183 (let (up down both neither
+ − 184 (standard (and (eq (key-binding " ")
+ − 185 'scroll-up)
+ − 186 (eq (key-binding "\^?")
+ − 187 'scroll-down)
+ − 188 (eq (key-binding "q")
+ − 189 'electric-help-exit)
+ − 190 (eq (key-binding "r")
+ − 191 'electric-help-retain))))
+ − 192 (Electric-command-loop
+ − 193 'exit
+ − 194 (function (lambda ()
+ − 195 (sit-for 0) ;necessary if last command was end-of-buffer or
+ − 196 ;beginning-of-buffer - otherwise pos-visible-in-window-p
+ − 197 ;will yield a wrong result.
+ − 198 (let ((min (pos-visible-in-window-p (point-min)))
+ − 199 (max (pos-visible-in-window-p (point-max))))
+ − 200 (cond (isearch-mode 'noprompt)
+ − 201 ((and min max)
+ − 202 (cond (standard "Press q to exit, r to retain ")
+ − 203 (neither)
+ − 204 (t (setq neither (substitute-command-keys "Press \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
+ − 205 (min
+ − 206 (cond (standard "Press SPC to scroll, q to exit, r to retain ")
+ − 207 (up)
+ − 208 (t (setq up (substitute-command-keys "Press \\[scroll-up] to scroll, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
+ − 209 (max
+ − 210 (cond (standard "Press DEL to scroll back, q to exit, r to retain ")
+ − 211 (down)
+ − 212 (t (setq down (substitute-command-keys "Press \\[scroll-down] to scroll back, \\[electric-help-exit] to exit, \\[electric-help-retain] to retain ")))))
+ − 213 (t
+ − 214 (cond (standard "Press SPC to scroll, DEL to scroll back, q to exit, r to retain ")
+ − 215 (both)
+ − 216 (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 ")))))))))
+ − 217 t))))
+ − 218
+ − 219
+ − 220
+ − 221 ;(defun electric-help-scroll-up (arg)
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+ − 222 ; "####Doc"
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+ − 223 ; (interactive "P")
+ − 224 ; (if (and (null arg) (pos-visible-in-window-p (point-max)))
+ − 225 ; (electric-help-exit)
+ − 226 ; (scroll-up arg)))
+ − 227
+ − 228 (defun electric-help-exit ()
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+ − 229 "####Doc"
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+ − 230 (interactive)
+ − 231 (throw 'exit t))
+ − 232
+ − 233 (defun electric-help-retain ()
+ − 234 "Exit `electric-help', retaining the current window/buffer configuration.
+ − 235 \(The *Help* buffer will not be selected, but \\[switch-to-buffer-other-window] RET
+ − 236 will select it.)"
+ − 237 (interactive)
+ − 238 ;; Make sure that we don't throw twice, even if two events cause
+ − 239 ;; calling this function:
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+ − 240 (if mouse-leave-buffer-hook
+ − 241 (progn
+ − 242 (setq mouse-leave-buffer-hook nil)
+ − 243 (throw 'exit '(retain)))))
+ − 244
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+ − 245
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+ − 246 ;(defun electric-help-undefined ()
+ − 247 ; (interactive)
+ − 248 ; (let* ((keys (this-command-keys))
+ − 249 ; (n (length keys)))
+ − 250 ; (if (or (= n 1)
+ − 251 ; (and (= n 2)
+ − 252 ; meta-flag
+ − 253 ; (eq (aref keys 0) meta-prefix-char)))
+ − 254 ; (setq unread-command-char last-input-char
+ − 255 ; current-prefix-arg prefix-arg)
+ − 256 ; ;;#### I don't care.
+ − 257 ; ;;#### The emacs command-loop is too much pure pain to
+ − 258 ; ;;#### duplicate
+ − 259 ; ))
+ − 260 ; (throw 'exit t))
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+ − 261
+ − 262 (defun electric-help-undefined ()
+ − 263 (interactive)
+ − 264 (error "%s is undefined -- Press %s to exit"
+ − 265 (mapconcat 'single-key-description (this-command-keys) " ")
+ − 266 (if (eq (key-binding "q") 'electric-help-exit)
+ − 267 "q"
+ − 268 (substitute-command-keys "\\[electric-help-exit]"))))
+ − 269
+ − 270
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+ − 271 ;#### this needs to be hairified (recursive help, anybody?)
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+ − 272 (defun electric-help-help ()
+ − 273 (interactive)
+ − 274 (if (and (eq (key-binding "q") 'electric-help-exit)
+ − 275 (eq (key-binding " ") 'scroll-up)
+ − 276 (eq (key-binding "\^?") 'scroll-down)
+ − 277 (eq (key-binding "r") 'electric-help-retain))
+ − 278 (message "SPC scrolls up, DEL scrolls down, q exits burying help buffer, r exits")
+ − 279 (message "%s" (substitute-command-keys "\\[scroll-up] scrolls up, \\[scroll-down] scrolls down, \\[electric-help-exit] exits burying help buffer, \\[electric-help-retain] exits")))
+ − 280 (sit-for 2))
+ − 281
+ − 282
+ − 283 ;;;###autoload
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+ − 284 (defun electric-helpify (fun &optional buffer-name)
+ − 285 (or buffer-name (setq buffer-name "*Help*"))
+ − 286 (let* ((p (symbol-function 'print-help-return-message))
+ − 287 (b (get-buffer buffer-name))
+ − 288 (tick (and b (buffer-modified-tick b))))
+ − 289 (and b (not (get-buffer-window b))
+ − 290 (setq b nil))
+ − 291 (if (unwind-protect
+ − 292 (save-window-excursion
+ − 293 (message "%s..." (capitalize (symbol-name fun)))
+ − 294 ;; kludge-o-rama
+ − 295 (fset 'print-help-return-message 'ignore)
+ − 296 (let ((a (call-interactively fun 'lambda)))
+ − 297 (let ((temp-buffer-show-function 'ignore))
+ − 298 (apply fun a)))
+ − 299 (message nil)
+ − 300 ;; Was a non-empty help buffer created/modified?
+ − 301 (let ((r (get-buffer buffer-name)))
+ − 302 (and r
+ − 303 ;(get-buffer-window r)
+ − 304 (or (not b)
+ − 305 (not (eq b r))
+ − 306 (not (eql tick (buffer-modified-tick b))))
+ − 307 (save-excursion
+ − 308 (set-buffer r)
+ − 309 (> (buffer-size) 0)))))
+ − 310 (fset 'print-help-return-message p)
+ − 311 )
+ − 312 (with-electric-help 'ignore buffer-name t))))
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+ − 313
+ − 314
+ − 315
+ − 316 ;; This is to be bound to M-x in ehelp mode. Retains ehelp buffer and then
+ − 317 ;; continues with execute-extended-command.
+ − 318 (defun electric-help-execute-extended (prefixarg)
+ − 319 (interactive "p")
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+ − 320 (setq to-be-executed '(execute-extended-command nil))
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+ − 321 (electric-help-retain))
+ − 322
+ − 323 ;; This is to be buond to C-x in ehelp mode. Retains ehelp buffer and then
+ − 324 ;; continues with ctrl-x prefix.
+ − 325 (defun electric-help-ctrl-x-prefix (prefixarg)
+ − 326 (interactive "p")
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+ − 327 (setq to-be-executed '(progn (message nil) (setq unread-command-char ?\C-x)))
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+ − 328 (electric-help-retain))
+ − 329
+ − 330
+ − 331 (defun electric-describe-key ()
+ − 332 (interactive)
+ − 333 (electric-helpify 'describe-key))
+ − 334
+ − 335 (defun electric-describe-mode ()
+ − 336 (interactive)
+ − 337 (electric-helpify 'describe-mode))
+ − 338
+ − 339 (defun electric-view-lossage ()
+ − 340 (interactive)
+ − 341 (electric-helpify 'view-lossage))
+ − 342
+ − 343 ;(defun electric-help-for-help ()
+ − 344 ; "See help-for-help"
+ − 345 ; (interactive)
+ − 346 ; )
+ − 347
+ − 348 (defun electric-describe-function ()
+ − 349 (interactive)
+ − 350 (electric-helpify 'describe-function))
+ − 351
+ − 352 (defun electric-describe-variable ()
+ − 353 (interactive)
+ − 354 (electric-helpify 'describe-variable))
+ − 355
+ − 356 (defun electric-describe-bindings ()
+ − 357 (interactive)
+ − 358 (electric-helpify 'describe-bindings))
+ − 359
+ − 360 (defun electric-describe-syntax ()
+ − 361 (interactive)
+ − 362 (electric-helpify 'describe-syntax))
+ − 363
+ − 364 (defun electric-command-apropos ()
+ − 365 (interactive)
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+ − 366 (electric-helpify 'command-apropos))
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+ − 367
+ − 368 ;(define-key help-map "a" 'electric-command-apropos)
+ − 369
+ − 370 (defun electric-apropos ()
+ − 371 (interactive)
+ − 372 (electric-helpify 'apropos))
+ − 373
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+ − 374
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+ − 375
+ − 376 ;;;; ehelp-map
+ − 377
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+ − 378 (defvar ehelp-map nil)
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+ − 379 (if ehelp-map
+ − 380 nil
+ − 381 ;; #### WTF? Why don't we just use substitute-key-definition
+ − 382 ;; like FSF does?
+ − 383 (let ((shadow '((apropos . electric-apropos)
+ − 384 (command-apropos . electric-command-apropos)
+ − 385 (describe-key . electric-describe-key)
+ − 386 (describe-mode . electric-describe-mode)
+ − 387 (view-lossage . electric-view-lossage)
+ − 388 (describe-function . electric-describe-function)
+ − 389 (describe-variable . electric-describe-variable)
+ − 390 (describe-bindings . electric-describe-bindings)
+ − 391 (describe-syntax . electric-describe-syntax)))
+ − 392 (map (make-sparse-keymap)))
+ − 393 (set-keymap-name map 'ehelp-map)
+ − 394 (set-keymap-parents map (list help-map))
+ − 395 ;; Shadow bindings which would be inherited from help-map
+ − 396 ;;#### This doesn't descend into sub-keymaps
+ − 397 (map-keymap (function (lambda (key binding)
+ − 398 (let ((tem (assq binding shadow)))
+ − 399 (if tem
+ − 400 (define-key map key (cdr tem))))))
+ − 401 help-map)
+ − 402 (setq ehelp-map map)
+ − 403 (fset 'ehelp-command map)))
+ − 404
+ − 405 ;; Do (define-key global-map "\C-h" 'ehelp-command) if you want to win
+ − 406
+ − 407 (provide 'ehelp)
+ − 408
+ − 409 ;;; ehelp.el ends here
