home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Fresh Fish 8
/
FreshFishVol8-CD1.bin
/
new
/
util
/
edit
/
jade
/
lisp
/
help.jl
< prev
next >
Wrap
Lisp/Scheme
|
1994-10-06
|
7KB
|
232 lines
;;;; help.jl -- Online help system
;;; Copyright (C) 1993, 1994 John Harper <jsh@ukc.ac.uk>
;;; This file is part of Jade.
;;; Jade is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2, or (at your option)
;;; any later version.
;;; Jade is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;; You should have received a copy of the GNU General Public License
;;; along with Jade; see the file COPYING. If not, write to
;;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
(provide 'help)
(defvar help-buffer (make-buffer "*Help*"))
(set-buffer-special help-buffer t)
(defvar help-keymap (make-keylist))
(bind-keys help-keymap
"SPC" 'next-screen
"BS" 'prev-screen
"q" 'bury-buffer)
(defvar help-prompt-keymap (make-keylist))
(bind-keys help-prompt-keymap
"a" 'apropos-function
"b" 'describe-keymap
"e" 'apropos-variable
"f" 'describe-function
"h" 'help-help
"Ctrl-h" 'help-help
"i" 'info
"Ctrl-i" '(info t)
"k" 'describe-key
"m" 'describe-mode
"?" 'help-help
"v" 'describe-variable
"SPC" '(progn (next-screen) (help))
"BS" '(progn (prev-screen) (help)))
(with-buffer help-buffer
(setq keymap-path '(help-keymap global-keymap)
mode-name "Help"
buffer-record-undo nil))
;;;###autoload
(defun help ()
"Entrance to the online-help system."
(interactive)
(message "Type: a b f h i k m v -- h for more help")
(setq next-keymap-path '(help-prompt-keymap)))
(defun help-help ()
"Displays some text describing the options in the help system."
(interactive)
(clear-buffer help-buffer)
(insert
"\nHelp mode -- Type one of the following:\n
a `apropos-function'
Search for functions which match a regular expression.
b `describe-keymap'
Print the key bindings which are currently active.
f `describe-function'
View the documentation for a particular function.
h `help-help'
Display this text.
i `info'
Enter the info hypertext viewer.
k `describe-key'
Display the command (and its documentation) that a particular
sequence of keys is currently bound to.
m `describe-mode'
Show the documentation for the edit mode of the current buffer.
v `describe-variable'
View the documentation and value of a variable."
(buffer-start) help-buffer)
(goto-buffer help-buffer)
(goto-buffer-start)
(help))
;; Setup the help-buffer for insertion of the help text
(defun help-setup ()
(clear-buffer help-buffer)
(goto-buffer help-buffer)
(insert "\n----\nType `q' to return to the buffer you were in.")
(goto-buffer-start))
(defun apropos-function (regexp)
(interactive "sRegular expression:")
(help-setup)
(format help-buffer "Apropos for expression %S:\n" regexp)
(print (apropos regexp 'fboundp) help-buffer)
(goto-buffer-start))
(defun apropos-variable (regexp)
(interactive "sRegular expression:")
(help-setup)
(format help-buffer "Apropos for expression %S:\n" regexp)
(print (apropos regexp 'boundp) help-buffer)
(goto-buffer-start))
(defun describe-keymap ()
"Print the full contents of the current keymap (and the keymaps that
it leads to)."
(interactive)
(let
((old-buf (current-buffer))
(km-list keymap-path))
(help-setup)
(print-keymap km-list old-buf)
(goto-buffer-start)))
(defun describe-function (fun &aux doc)
"Display the documentation of a function, macro or special-form."
(interactive "aDescribe function:")
(setq doc (documentation fun))
(help-setup)
(let*
((fval (symbol-function fun))
(type (cond
((special-form-p fval)
"Special Form")
((subrp fval)
"Built-in Function")
((eq (car fval) 'macro)
"Macro")
(t
"Function"))))
(when (consp fval)
;; Check if it's been compiled.
(when (assq 'jade-byte-code fval)
;; compiled forms
(setq type (concat "Compiled " type))))
(format help-buffer "\n%s: %s\n\n" type fun)
(when (fboundp fun)
(unless (subrp fval)
;; A Lisp function or macro, print its argument spec.
(let
((lambda-list (nth (if (eq (car fval) 'macro) 2 1) fval)))
(prin1 fun help-buffer)
(when (eq (car lambda-list) 'lambda)
;; A macro
(setq lambda-list (cdr lambda-list)))
;; Print the arg list (one at a time)
(while lambda-list
(let
((arg-name (symbol-name (car lambda-list))))
;; Unless the argument starts with a `&' print it in capitals
(unless (= (aref arg-name 0) ?&)
(setq arg-name (translate-string (copy-sequence arg-name)
upcase-table)))
(format help-buffer " %s" arg-name))
(setq lambda-list (cdr lambda-list)))
(insert "\n\n")))))
(insert (or doc "Undocumented."))
(insert "\n")
(goto-buffer-start))
(defun describe-variable (var)
(interactive "vDescribe variable:")
(let
((doc (documentation var t))
(old-buf (current-buffer)))
(help-setup)
(format help-buffer
"\n%s: %s\nCurrent value: %S\n\n%s\n"
(if (const-variable-p var)
"Constant"
"Variable")
(symbol-name var)
(with-buffer old-buf (symbol-value var t))
(or doc "Undocumented."))
(goto-buffer-start)))
;;;###autoload
(defun describe-mode ()
"Print the help text for the current editing mode."
(interactive)
(let
((mode major-mode))
(help-setup)
(let
((doc (documentation mode)))
(when (stringp doc)
(format help-buffer "\n%s\n" doc)
(goto-buffer-start)))))
;;;###autoload
(defun documentation (symbol &optional is-variable)
"Returns the documentation-string for SYMBOL. If IS-VARIABLE is t the
documentation for the variable stored in SYMBOL is returned, else
the function doc is provided."
(when (symbolp symbol)
(let
(doc)
(if is-variable
(setq doc (get symbol 'variable-documentation))
(when (eq (car (symbol-function symbol)) 'autoload)
(load (nth 1 (symbol-function symbol))))
(setq symbol (symbol-function symbol))
(cond
((subrp symbol)
(setq doc (subr-documentation symbol)))
((or (eq 'macro (car symbol)) (eq 'special (car symbol)))
(setq doc (nth 3 symbol)))
(t
(setq doc (nth 2 symbol)))))
(when (numberp doc)
(setq doc (get-doc-string doc)))
(when (stringp doc)
doc))))
;;;###autoload
(defun document-var (symbol doc-string)
"Sets the `variable-documentation' property of SYMBOL to DOC-STRING."
(put symbol 'variable-documentation doc-string)
symbol)