;;; help.el --- help commands for Emacs
-;; Copyright (C) 1985, 1986, 1993, 1994, 1998 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: help, internal
;;; Commentary:
;; This code implements GNU Emacs' on-line help system, the one invoked by
-;;`M-x help-for-help'.
+;; `M-x help-for-help'.
;;; Code:
;; Get the macro make-help-screen when this is compiled,
;; or run interpreted, but not when the compiled code is loaded.
(eval-when-compile (require 'help-macro))
+(eval-when-compile (require 'view))
(defvar help-map (make-sparse-keymap)
"Keymap for characters following the Help key.")
(autoload 'finder-by-keyword "finder"
"Find packages matching a given keyword." t)
+(define-key help-map "P" 'view-emacs-problems)
+
(define-key help-map "s" 'describe-syntax)
(define-key help-map "t" 'help-with-tutorial)
;; Documentation only, since we use minor-mode-overriding-map-alist.
(define-key help-mode-map "\r" 'help-follow)
-;; Font-locking is incompatible with the new xref stuff.
-;(defvar help-font-lock-keywords
-; (eval-when-compile
-; (let ((name-char "[-+a-zA-Z0-9_*]") (sym-char "[-+a-zA-Z0-9_:*]"))
-; (list
-; ;;
-; ;; The symbol itself.
-; (list (concat "\\`\\(" name-char "+\\)\\(\\(:\\)\\|\\('\\)\\)")
-; '(1 (if (match-beginning 3)
-; font-lock-function-name-face
-; font-lock-variable-name-face)))
-; ;;
-; ;; Words inside `' which tend to be symbol names.
-; (list (concat "`\\(" sym-char sym-char "+\\)'")
-; 1 'font-lock-constant-face t)
-; ;;
-; ;; CLisp `:' keywords as references.
-; (list (concat "\\<:" sym-char "+\\>") 0 'font-lock-builtin-face t))))
-; "Default expressions to highlight in Help mode.")
-
(defvar help-xref-stack nil
"A stack of ways by which to return to help buffers after following xrefs.
Used by `help-follow' and `help-xref-go-back'.
(setq-default help-xref-stack nil help-xref-stack-item nil)
+(defcustom help-mode-hook nil
+ "Hook run by `help-mode'."
+ :type 'hook
+ :group 'help)
+
(defun help-mode ()
"Major mode for viewing help text and navigating references in it.
Entry to this mode runs the normal hook `help-mode-hook'.
(goto-char (point-min))
(set-buffer-modified-p nil))))
+(defun mode-line-key-binding (key)
+ "Value is the binding of KEY in the mode line or nil if none."
+ (let (string-info defn)
+ (when (and (eq 'mode-line (aref key 0))
+ (consp (setq string-info (nth 4 (event-start (aref key 1))))))
+ (let* ((string (car string-info))
+ (pos (cdr string-info))
+ (local-map (and (> pos 0)
+ (< pos (length string))
+ (get-text-property pos 'local-map string))))
+ (setq defn (and local-map (lookup-key local-map key)))))
+ defn))
+
(defun describe-key-briefly (key &optional insert)
"Print the name of the function KEY invokes. KEY is a string.
If INSERT (the prefix arg) is non-nil, insert the message in the buffer."
(set-buffer (window-buffer window))
(goto-char position)))
;; Ok, now look up the key and name the command.
- (let ((defn (key-binding key))
+ (let ((defn (or (mode-line-key-binding key)
+ (key-binding key)))
(key-desc (key-description key)))
(if (or (null defn) (integerp defn))
(princ (format "%s is undefined" key-desc))
(progn
(set-buffer (window-buffer window))
(goto-char position)))
- (let ((defn (key-binding key)))
+ (let ((defn (or (mode-line-key-binding key) (key-binding key))))
(if (or (null defn) (integerp defn))
(message "%s is undefined" (key-description key))
(with-output-to-temp-buffer "*Help*"
(defun view-emacs-FAQ ()
"Display the Emacs Frequently Asked Questions (FAQ) file."
(interactive)
- (find-file-read-only (expand-file-name "FAQ" data-directory)))
+;;; (find-file-read-only (expand-file-name "FAQ" data-directory))
+ (info "(emacs-faq)"))
+
+(defun view-emacs-problems ()
+ "Display info on known problems with Emacs and possible workarounds."
+ (interactive)
+ (view-file (expand-file-name "PROBLEMS" data-directory)))
(defun view-lossage ()
"Display last 100 input keystrokes."
i info. The info documentation reader.
I describe-input-method. Describe a specific input method (if you type
its name) or the current input method (if you type just RET).
+C-i info-lookup-symbol. Display the definition of a specific symbol
+ as found in the manual for the language this buffer is written in.
k describe-key. Type a command key sequence;
it displays the full documentation.
C-k Info-goto-emacs-key-command-node. Type a command key sequence;
it takes you to the Info node for the command bound to that key.
-l view-lossage. Shows last 100 characters you typed.
+l view-lossage. Show last 100 characters you typed.
L describe-language-environment. This describes either the a
specific language environment (if you type its name)
or the current language environment (if you type just RET).
m describe-mode. Print documentation of current minor modes,
and the current major mode, including their special commands.
-n view-emacs-news. Shows emacs news file.
+n view-emacs-news. Display news of recent Emacs changes.
p finder-by-keyword. Find packages matching a given topic keyword.
s describe-syntax. Display contents of syntax table, plus explanations
t help-with-tutorial. Select the Emacs learn-by-doing tutorial.
(if (eq (nth 4 def) 'keymap) "keymap"
(if (nth 4 def) "Lisp macro" "Lisp function"))
))
+ ;; perhaps use keymapp here instead
+ ((eq (car-safe def) 'keymap)
+ (let ((is-full nil)
+ (elts (cdr-safe def)))
+ (while elts
+ (if (char-table-p (car-safe elts))
+ (setq is-full t
+ elts nil))
+ (setq elts (cdr-safe elts)))
+ (if is-full
+ "a full keymap"
+ "a sparse keymap")))
(t "")))
(when (and parens (not (equal string "")))
(setq need-close t)
(save-excursion
(save-match-data
(if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
- (help-xref-button 1 #'describe-function def)))))
+ (help-xref-button 1 #'describe-function def
+ "mouse-2, RET: describe this function")))))
(or file-name
(setq file-name (symbol-file function)))
(if file-name
(find-function-noselect arg)))
(pop-to-buffer (car location))
(goto-char (cdr location))))
- function)))))
+ function
+ "mouse-2, RET: find function's definition")))))
(if need-close (princ ")"))
(princ ".")
(terpri)
(car (append def nil)))
((eq (car-safe def) 'lambda)
(nth 1 def))
+ ((and (eq (car-safe def) 'autoload)
+ (not (eq (nth 4 def) 'keymap)))
+ (concat "[Arg list not available until "
+ "function definition is loaded.]"))
(t t))))
- (if (listp arglist)
- (progn
- (princ (cons (if (symbolp function) function "anonymous")
- (mapcar (lambda (arg)
- (if (memq arg '(&optional &rest))
- arg
- (intern (upcase (symbol-name arg)))))
- arglist)))
- (terpri))))
+ (cond ((listp arglist)
+ (princ (cons (if (symbolp function) function "anonymous")
+ (mapcar (lambda (arg)
+ (if (memq arg '(&optional &rest))
+ arg
+ (intern (upcase (symbol-name arg)))))
+ arglist)))
+ (terpri))
+ ((stringp arglist)
+ (princ arglist)
+ (terpri))))
(let ((doc (documentation function)))
(if doc
(progn (terpri)
(princ doc)
- (help-setup-xref (list #'describe-function function) interactive-p))
+ (with-current-buffer standard-output
+ (beginning-of-line)
+ ;; Builtins get the calling sequence at the end of
+ ;; the doc string. Move it to the same place as
+ ;; for other functions.
+ (when (looking-at (format "(%S[ )]" function))
+ (let ((start (point-marker)))
+ (goto-char (point-min))
+ (forward-paragraph)
+ (insert-buffer-substring (current-buffer) start)
+ (insert ?\n)
+ (delete-region (1- start) (point-max))
+ (goto-char (point-max)))))
+ (help-setup-xref (list #'describe-function function)
+ interactive-p))
(princ "not documented")))))
(defun variable-at-point ()
(set-buffer standard-output)
(if (> (count-lines (point-min) (point-max)) 10)
(progn
+ (set-syntax-table emacs-lisp-mode-syntax-table)
(goto-char (point-min))
(if valvoid
(forward-line 1)
;; Note, it is not reliable to test only for a custom-type property
;; because those are only present after the var's definition
;; has been loaded.
- (if (or (user-variable-p variable)
- (get variable 'custom-loads)
- (get variable 'custom-type))
+ (if (or (get variable 'custom-type) ; after defcustom
+ (get variable 'custom-loads) ; from loaddefs.el
+ (get variable 'standard-value)) ; from cus-start.el
(let ((customize-label "customize"))
(terpri)
(terpri)
(re-search-backward
(concat "\\(" customize-label "\\)") nil t)
(help-xref-button 1 #'(lambda (v)
- (customize-variable v)) variable)
+ (customize-variable v))
+ variable
+ "mouse-2, RET: customize variable")
))))
;; Make a hyperlink to the library if appropriate. (Don't
;; change the format of the buffer's initial line in case
(with-current-buffer "*Help*"
(save-excursion
(re-search-backward "`\\([^`']+\\)'" nil t)
- (help-xref-button 1 (lambda (arg)
- (let ((location
- (find-variable-noselect arg)))
- (pop-to-buffer (car location))
- (goto-char (cdr location))))
- variable)))))
+ (help-xref-button
+ 1 (lambda (arg)
+ (let ((location
+ (find-variable-noselect arg)))
+ (pop-to-buffer (car location))
+ (goto-char (cdr location))))
+ variable "mouse-2, RET: find variable's definition")))))
(print-help-return-message)
(save-excursion
(setq val (completing-read (if fn
(format "Where is command (default %s): " fn)
"Where is command: ")
- obarray 'fboundp t))
+ obarray 'commandp t))
(list (if (equal val "")
fn (intern val))
current-prefix-arg)))
(defcustom help-highlight-p t
"*If non-nil, `help-make-xrefs' highlight cross-references.
Under a window system it highlights them with face defined by
-`help-highlight-face'. On a character terminal highlighted
-references look like cross-references in info mode."
+`help-highlight-face'."
:group 'help
:version "20.3"
:type 'boolean)
:version "20.3"
:type 'face)
-(defvar help-back-label "[back]"
+(defvar help-back-label (purecopy "[back]")
"Label to use by `help-make-xrefs' for the go-back reference.")
-(defvar help-xref-symbol-regexp
- (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
- "\\(function\\|command\\)\\|"
- "\\(symbol\\)\\)\\s-+\\)?"
- ;; Note starting with word-syntax character:
- "`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'")
+(defconst help-xref-symbol-regexp
+ (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
+ "\\(function\\|command\\)\\|"
+ "\\(symbol\\)\\)\\s-+\\)?"
+ ;; Note starting with word-syntax character:
+ "`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'"))
"Regexp matching doc string references to symbols.
The words preceding the quoted symbol can be used in doc strings to
distinguish references to variables, functions and symbols.")
-(defvar help-xref-info-regexp
- "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'"
+(defconst help-xref-info-regexp
+ (purecopy "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'")
"Regexp matching doc string references to an Info node.")
(defun help-setup-xref (item interactive-p)
(save-match-data
(unless (string-match "^([^)]+)" data)
(setq data (concat "(emacs)" data))))
- (help-xref-button 1 #'info data))))
+ (help-xref-button 1 #'info data
+ "mouse-2, RET: read this Info node"))))
;; Quoted symbols
(save-excursion
(while (re-search-forward help-xref-symbol-regexp nil t)
((match-string 3) ; `variable' &c
(and (boundp sym) ; `variable' doesn't ensure
; it's actually bound
- (help-xref-button 6 #'describe-variable sym)))
+ (help-xref-button
+ 6 #'describe-variable sym
+ "mouse-2, RET: describe this variable")))
((match-string 4) ; `function' &c
(and (fboundp sym) ; similarly
- (help-xref-button 6 #'describe-function sym)))
+ (help-xref-button
+ 6 #'describe-function sym
+ "mouse-2, RET: describe this function")))
((match-string 5)) ; nothing for symbol
((and (boundp sym) (fboundp sym))
;; We can't intuit whether to use the
;; variable or function doc -- supply both.
- (help-xref-button 6 #'help-xref-interned sym))
+ (help-xref-button
+ 6 #'help-xref-interned sym
+ "mouse-2, RET: describe this symbol"))
((boundp sym)
- (help-xref-button 6 #'describe-variable sym))
- ((fboundp sym)
- (help-xref-button 6 #'describe-function sym)))))))
+ (help-xref-button
+ 6 #'describe-variable sym
+ "mouse-2, RET: describe this variable"))
+ ((fboundp sym)
+ (help-xref-button
+ 6 #'describe-function sym
+ "mouse-2, RET: describe this function")))))))
;; An obvious case of a key substitution:
(save-excursion
(while (re-search-forward
"\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t)
(let ((sym (intern-soft (match-string 1))))
(if (fboundp sym)
- (help-xref-button 1 #'describe-function sym)))))
+ (help-xref-button
+ 1 #'describe-function sym
+ "mouse-2, RET: describe this command")))))
;; Look for commands in whole keymap substitutions:
(save-excursion
;; Make sure to find the first keymap.
(while
;; Ignore single blank lines in table, but not
;; double ones, which should terminate it.
- (and (not (looking-at "\n\n"))
+ (and (not (looking-at "\n\\s-*\n"))
(progn
(and (eolp) (forward-line))
(end-of-line)
(let ((sym (intern-soft (match-string 0))))
(if (fboundp sym)
(help-xref-button
- 0 #'describe-function sym))))
+ 0 #'describe-function sym
+ "mouse-2, RET: describe this function"))))
(zerop (forward-line)))))))))
(set-syntax-table stab))
;; Make a back-reference in this buffer if appropriate.
map))))
(set-buffer-modified-p old-modified))))
-(defun help-xref-button (match-number function data)
+(defun help-xref-button (match-number function data &optional help-echo)
"Make a hyperlink for cross-reference text previously matched.
MATCH-NUMBER is the subexpression of interest in the last matched
regexp. FUNCTION is a function to invoke when the button is
activated, applied to DATA. DATA may be a single value or a list.
-See `help-make-xrefs'."
+See `help-make-xrefs'.
+If optional arg HELP-ECHO is supplied, it is used as a help string."
;; Don't mung properties we've added specially in some instances.
(unless (get-text-property (match-beginning match-number) 'help-xref)
(add-text-properties (match-beginning match-number)
(if (listp data)
data
(list data)))))
+ (if help-echo
+ (put-text-property (match-beginning match-number)
+ (match-end match-number)
+ 'help-echo help-echo))
(if help-highlight-p
(put-text-property (match-beginning match-number)
(match-end match-number)
Both variable and function documentation are extracted into a single
help buffer."
- (let ((fdoc (describe-function symbol)))
- (describe-variable symbol)
- ;; We now have a help buffer on the variable. Insert the function
- ;; text after it.
- (goto-char (point-max))
- (let ((inhibit-read-only t))
- (insert "\n\n" fdoc)))
- (goto-char (point-min))
- (help-setup-xref (list #'help-xref-interned symbol) nil))
+ (let ((fdoc (when (fboundp symbol) (describe-function symbol))))
+ (when (or (boundp symbol) (not fdoc))
+ (describe-variable symbol)
+ ;; We now have a help buffer on the variable. Insert the function
+ ;; text before it.
+ (when fdoc
+ (with-current-buffer "*Help*"
+ (goto-char (point-min))
+ (let ((inhibit-read-only t))
+ (insert fdoc "\n\n" (symbol-name symbol) " is also a variable.\n\n"))
+ (help-setup-xref (list #'help-xref-interned symbol) nil))))))
(defun help-xref-mode (buffer)
"Do a `describe-mode' for the specified BUFFER."
args (cddr item))
(setq help-xref-stack (cdr help-xref-stack))))
(apply method args)
- (goto-char position)))
+ ;; We're not in the right buffer to do this, and we don't actually
+ ;; know which we should be in.
+ ;;(goto-char position)
+ ))
(defun help-go-back ()
"Invoke the [back] button (if any) in the Help mode buffer."
For the cross-reference format, see `help-make-xrefs'."
(interactive "d")
- (let* ((help-data (or (and (not (= pos (point-max)))
- (get-text-property pos 'help-xref))
- (and (not (= pos (point-min)))
- (get-text-property (1- pos) 'help-xref))))
+ (unless pos
+ (setq pos (point)))
+ (let* ((help-data
+ (or (and (not (= pos (point-max)))
+ (get-text-property pos 'help-xref))
+ (and (not (= pos (point-min)))
+ (get-text-property (1- pos) 'help-xref))
+ ;; check if the symbol under point is a function or variable
+ (let ((sym
+ (intern
+ (save-excursion
+ (goto-char pos) (skip-syntax-backward "w_")
+ (buffer-substring (point)
+ (progn (skip-syntax-forward "w_")
+ (point)))))))
+ (when (or (boundp sym) (fboundp sym))
+ (list #'help-xref-interned sym)))))
(method (car help-data))
(args (cdr help-data)))
- (setq help-xref-stack (cons (cons (point) help-xref-stack-item)
- help-xref-stack))
- (setq help-xref-stack-item nil)
(when help-data
+ (setq help-xref-stack (cons (cons (point) help-xref-stack-item)
+ help-xref-stack))
+ (setq help-xref-stack-item nil)
;; There is a reference at point. Follow it.
(apply method args))))
(new-height (max (min text-height max-height) min-height)))
(enlarge-window (- new-height win-height)))))
+;; `help-manyarg-func-alist' is defined primitively (in doc.c).
+;; New primitives with `MANY' or `UNEVALLED' arglists should be added
+;; to this alist.
+;; The parens and function name are redundant, but it's messy to add
+;; them in `documentation'.
+(defconst help-manyarg-func-alist
+ (purecopy
+ '((list . "(list &rest OBJECTS)")
+ (vector . "(vector &rest OBJECTS)")
+ (make-byte-code . "(make-byte-code &rest ELEMENTS)")
+ (call-process
+ . "(call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)")
+ (string . "(string &rest CHARACTERS)")
+ (+ . "(+ &rest NUMBERS-OR-MARKERS)")
+ (- . "(- &optional NUMBER-OR-MARKER &rest MORE-NUMBERS-OR-MARKERS)")
+ (* . "(* &rest NUMBERS-OR-MARKERS)")
+ (/ . "(/ DIVIDEND DIVISOR &rest DIVISORS)")
+ (max . "(max NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)")
+ (min . "(min NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)")
+ (logand . "(logand &rest INTS-OR-MARKERS)")
+ (logior . "(logior &rest INTS-OR-MARKERS)")
+ (logxor . "(logxor &rest INTS-OR-MARKERS)")
+ (encode-time
+ . "(encode-time SECOND MINUTE HOUR DAY MONTH YEAR &optional ZONE)")
+ (insert . "(insert &rest ARGS)")
+ (insert-before-markers . "(insert-before-markers &rest ARGS)")
+ (message . "(message STRING &rest ARGUMENTS)")
+ (message-box . "(message-box STRING &rest ARGUMENTS)")
+ (message-or-box . "(message-or-box STRING &rest ARGUMENTS)")
+ (propertize . "(propertize STRING &rest PROPERTIES)")
+ (format . "(format STRING &rest OBJECTS)")
+ (apply . "(apply FUNCTION &rest ARGUMENTS)")
+ (run-hooks . "(run-hooks &rest HOOKS)")
+ (run-hook-with-args . "(run-hook-with-args HOOK &rest ARGS)")
+ (run-hook-with-args-until-failure
+ . "(run-hook-with-args-until-failure HOOK &rest ARGS)")
+ (run-hook-with-args-until-success
+ . "(run-hook-with-args-until-success HOOK &rest ARGS)")
+ (funcall . "(funcall FUNCTION &rest ARGUMENTS)")
+ (append . "(append &rest SEQUENCES)")
+ (concat . "(concat &rest SEQUENCES)")
+ (vconcat . "(vconcat vconcat)")
+ (nconc . "(nconc &rest LISTS)")
+ (widget-apply . "(widget-apply WIDGET PROPERTY &rest ARGS)")
+ (make-hash-table . "(make-hash-table &rest KEYWORD-ARGS)")
+ (insert-string . "(insert-string &rest ARGS)")
+ (start-process . "(start-process NAME BUFFER PROGRAM &rest PROGRAM-ARGS)")
+ (setq-default . "(setq-default SYMBOL VALUE [SYMBOL VALUE...])")
+ (save-excursion . "(save-excursion &rest BODY)")
+ (save-current-buffer . "(save-current-buffer &rest BODY)")
+ (save-restriction . "(save-restriction &rest BODY)")
+ (or . "(or CONDITIONS ...)")
+ (and . "(and CONDITIONS ...)")
+ (if . "(if COND THEN ELSE...)")
+ (cond . "(cond CLAUSES...)")
+ (progn . "(progn BODY ...)")
+ (prog1 . "(prog1 FIRST BODY...)")
+ (prog2 . "(prog2 X Y BODY...)")
+ (setq . "(setq SYM VAL SYM VAL ...)")
+ (quote . "(quote ARG)")
+ (function . "(function ARG)")
+ (defun . "(defun NAME ARGLIST [DOCSTRING] BODY...)")
+ (defmacro . "(defmacro NAME ARGLIST [DOCSTRING] BODY...)")
+ (defvar . "(defvar SYMBOL [INITVALUE DOCSTRING])")
+ (defconst . "(defconst SYMBOL INITVALUE [DOCSTRING])")
+ (let* . "(let* VARLIST BODY...)")
+ (let . "(let VARLIST BODY...)")
+ (while . "(while TEST BODY...)")
+ (catch . "(catch TAG BODY...)")
+ (unwind-protect . "(unwind-protect BODYFORM UNWINDFORMS...)")
+ (condition-case . "(condition-case VAR BODYFORM HANDLERS...)")
+ (track-mouse . "(track-mouse BOFY ...)")
+ (ml-if . "(ml-if COND THEN ELSE...)")
+ (ml-provide-prefix-argument . "(ml-provide-prefix-argument ARG1 ARG2)")
+ (with-output-to-temp-buffer
+ . "(with-output-to-temp-buffer BUFFNAME BODY ...)")
+ (save-window-excursion . "(save-window-excursion BODY ...)"))))
+
;;; help.el ends here