;;; eldoc.el --- show function arglist or variable docstring in echo area
-;; Copyright (C) 1995 Noah S. Friedman
+;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
-;; Author: Noah Friedman <friedman@prep.ai.mit.edu>
-;; Maintainer: friedman@prep.ai.mit.edu
+;; Author: Noah Friedman <friedman@splode.com>
+;; Maintainer: friedman@splode.com
;; Keywords: extensions
-;; Status: Works in Emacs 19 and XEmacs.
;; Created: 1995-10-06
-;; LCD Archive Entry:
-;; eldoc|Noah Friedman|friedman@prep.ai.mit.edu|
-;; show function arglist or variable docstring in echo area|
-;; $Date: 1996/07/14 16:46:25 $|$Revision: 1.6 $|~/misc/eldoc.el.gz|
+;; This file is part of GNU Emacs.
-;; $Id: eldoc.el,v 1.6 1996/07/14 16:46:25 friedman Exp friedman $
-
-;; This program is free software; you can redistribute it and/or modify
+;; GNU Emacs 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.
-;;
-;; This program is distributed in the hope that it will be useful,
+
+;; GNU Emacs 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 this program; if not, you can either send email to this
-;; program's maintainer or write to: The Free Software Foundation,
-;; Inc.; 59 Temple Place, Suite 330; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
-;; This program was inspired by the behavior of the Lisp Machine "mouse
-;; documentation window"; as you type a function's symbol name as part of a
-;; sexp, it will print the argument list for that function. However, this
-;; program's behavior is different in a couple of significant ways. For
-;; one, you need not actually type the function name; you need only move
-;; point around in a sexp that calls it. However, if point is over a
-;; documented variable, it will print the one-line documentation for that
-;; variable instead, to remind you of that variable's purpose.
+;; This program was inspired by the behavior of the "mouse documentation
+;; window" on many Lisp Machine systems; as you type a function's symbol
+;; name as part of a sexp, it will print the argument list for that
+;; function. Behavior is not identical; for example, you need not actually
+;; type the function name, you need only move point around in a sexp that
+;; calls it. Also, if point is over a documented variable, it will print
+;; the one-line documentation for that variable instead, to remind you of
+;; that variable's meaning.
;; One useful way to enable this minor mode is to put the following in your
;; .emacs:
;;
-;; (autoload 'turn-on-eldoc-mode "eldoc" nil t)
;; (add-hook 'emacs-lisp-mode-hook 'turn-on-eldoc-mode)
;; (add-hook 'lisp-interaction-mode-hook 'turn-on-eldoc-mode)
+;; (add-hook 'ielm-mode-hook 'turn-on-eldoc-mode)
-;;; Code:
-
-;;;###autoload
-(defvar eldoc-mode nil
- "*If non-nil, show the defined parameters for the elisp function near point.
-
-For the emacs lisp function at the beginning of the sexp which point is
-within, show the defined parameters for the function in the echo area.
-This information is extracted directly from the function or macro if it is
-in pure lisp.
+;; Major modes for other languages may use Eldoc by defining an
+;; appropriate function as the buffer-local value of
+;; `eldoc-documentation-function'.
-If the emacs function is a subr, the parameters are obtained from the
-documentation string if possible.
+;;; Code:
-If point is over a documented variable, print that variable's docstring
-instead; see function `eldoc-print-var-docstring'.
+(require 'help-fns) ;For fundoc-usage handling functions.
-This variable is buffer-local.")
-(make-variable-buffer-local 'eldoc-mode)
+(defgroup eldoc nil
+ "Show function arglist or variable docstring in echo area."
+ :group 'lisp
+ :group 'extensions)
-(defvar eldoc-idle-delay 0.50
+(defcustom eldoc-idle-delay 0.50
"*Number of seconds of idle time to wait before printing.
If user input arrives before this interval of time has elapsed after the
last input, no documentation will be printed.
-If this variable is set to 0, no idle time is required.")
+If this variable is set to 0, no idle time is required."
+ :type 'number
+ :group 'eldoc)
-(defvar eldoc-argument-case 'upcase
+;;;###autoload
+(defcustom eldoc-minor-mode-string " ElDoc"
+ "*String to display in mode line when Eldoc Mode is enabled; nil for none."
+ :type '(choice string (const :tag "None" nil))
+ :group 'eldoc)
+
+(defcustom eldoc-argument-case 'upcase
"Case to display argument names of functions, as a symbol.
This has two preferred values: `upcase' or `downcase'.
Actually, any name of a function which takes a string as an argument and
-returns another string is acceptable.")
-
-(defvar eldoc-mode-message-commands nil
- "*Obarray of command names where it is appropriate to print in the echo area.
-
-This is not done for all commands since some print their own
-messages in the echo area, and these functions would instantly overwrite
-them. But self-insert-command as well as most motion commands are good
-candidates.
-
-It is probably best to manipulate this data structure with the commands
-`eldoc-add-command' and `eldoc-remove-command'.")
-
-(cond ((null eldoc-mode-message-commands)
- ;; If you increase the number of buckets, keep it a prime number.
- (setq eldoc-mode-message-commands (make-vector 31 0))
- (let ((list '("self-insert-command"
- "next-" "previous-"
- "forward-" "backward-"
- "beginning-of-" "end-of-"
- "goto-"
- "recenter"
- "scroll-"))
- (syms nil))
- (while list
- (setq syms (all-completions (car list) obarray 'fboundp))
- (setq list (cdr list))
- (while syms
- (set (intern (car syms) eldoc-mode-message-commands) t)
- (setq syms (cdr syms)))))))
-
-;; Bookkeeping; the car contains the last symbol read from the buffer.
-;; The cdr contains the string last displayed in the echo area, so it can
-;; be printed again if necessary without reconsing.
-(defvar eldoc-last-data '(nil . nil))
-
-(defvar eldoc-minor-mode-string " ElDoc"
- "*String to display in mode line when Eldoc Mode is enabled.")
-
-;; Put this minor mode on the global minor-mode-alist.
-(or (assq 'eldoc-mode (default-value 'minor-mode-alist))
- (setq-default minor-mode-alist
- (append (default-value 'minor-mode-alist)
- '((eldoc-mode eldoc-minor-mode-string)))))
-
-;; In emacs 19.29 and later, and XEmacs 19.13 and later, all messages are
-;; recorded in a log. Do not put eldoc messages in that log since
-;; they are Legion.
-(defmacro eldoc-message (&rest args)
- (if (fboundp 'display-message)
- ;; XEmacs 19.13 way of preventing log messages.
- (list 'display-message '(quote no-log) (apply 'list 'format args))
- (list 'let (list (list 'message-log-max 'nil))
- (apply 'list 'message args))))
+returns another string is acceptable."
+ :type '(radio (function-item upcase)
+ (function-item downcase)
+ function)
+ :group 'eldoc)
+
+(defcustom eldoc-echo-area-use-multiline-p 'truncate-sym-name-if-fit
+ "*Allow long eldoc messages to resize echo area display.
+If value is t, never attempt to truncate messages; complete symbol name
+and function arglist or 1-line variable documentation will be displayed
+even if echo area must be resized to fit.
+
+If value is any non-nil value other than t, symbol name may be truncated
+if it will enable the function arglist or documentation string to fit on a
+single line without resizing window. Otherwise, behavior is just like
+former case.
+
+If value is nil, messages are always truncated to fit in a single line of
+display in the echo area. Function or variable symbol name may be
+truncated to make more of the arglist or documentation string visible."
+ :type '(radio (const :tag "Always" t)
+ (const :tag "Never" nil)
+ (const :tag "Yes, but truncate symbol names if it will\
+ enable argument list to fit on one line" truncate-sym-name-if-fit))
+ :group 'eldoc)
+
+;;; No user options below here.
+
+(defvar eldoc-message-commands-table-size 31
+ "This is used by eldoc-add-command to initialize eldoc-message-commands
+as an obarray.
+It should probably never be necessary to do so, but if you
+choose to increase the number of buckets, you must do so before loading
+this file since the obarray is initialized at load time.
+Remember to keep it a prime number to improve hash performance.")
+
+(defconst eldoc-message-commands
+ (make-vector eldoc-message-commands-table-size 0)
+ "Commands after which it is appropriate to print in the echo area.
+Eldoc does not try to print function arglists, etc. after just any command,
+because some commands print their own messages in the echo area and these
+functions would instantly overwrite them. But self-insert-command as well
+as most motion commands are good candidates.
+This variable contains an obarray of symbols; do not manipulate it
+directly. Instead, use `eldoc-add-command' and `eldoc-remove-command'.")
+
+(defconst eldoc-last-data (make-vector 3 nil)
+ "Bookkeeping; elements are as follows:
+ 0 - contains the last symbol read from the buffer.
+ 1 - contains the string last displayed in the echo area for that
+ symbol, so it can be printed again if necessary without reconsing.
+ 2 - 'function if function args, 'variable if variable documentation.")
+(defvar eldoc-last-message nil)
+
+(defvar eldoc-timer nil "eldoc's timer object.")
+
+(defvar eldoc-current-idle-delay eldoc-idle-delay
+ "idle time delay currently in use by timer.
+This is used to determine if `eldoc-idle-delay' is changed by the user.")
\f
;;;###autoload
-(defun eldoc-mode (&optional prefix)
- "*If non-nil, then enable eldoc-mode (see variable docstring)."
- (interactive "P")
-
- ;; Make sure it's on the post-command-idle-hook if defined, otherwise put
- ;; it on post-command-hook. The former first appeared in Emacs 19.30.
- (add-hook (if (boundp 'post-command-idle-hook)
- 'post-command-idle-hook
- 'post-command-hook)
- 'eldoc-mode-print-current-symbol-info)
-
- (setq eldoc-mode (if prefix
- (>= (prefix-numeric-value prefix) 0)
- (not eldoc-mode)))
-
- (and (interactive-p)
- (if eldoc-mode
- (message "eldoc-mode is enabled")
- (message "eldoc-mode is disabled")))
- eldoc-mode)
+(define-minor-mode eldoc-mode
+ "Toggle ElDoc mode on or off.
+In ElDoc mode, the echo area displays information about a
+function or variable in the text where point is. If point is
+on a documented variable, it displays the first line of that
+variable's doc string. Otherwise it displays the argument list
+of the function called in the expression point is on.
+
+With prefix ARG, turn ElDoc mode on if and only if ARG is positive."
+ :group 'eldoc :lighter eldoc-minor-mode-string
+ (setq eldoc-last-message nil)
+ (if eldoc-mode
+ (progn
+ (add-hook 'post-command-hook 'eldoc-schedule-timer nil t)
+ (add-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area t))
+ (remove-hook 'post-command-hook 'eldoc-schedule-timer)
+ (remove-hook 'pre-command-hook 'eldoc-pre-command-refresh-echo-area)))
;;;###autoload
(defun turn-on-eldoc-mode ()
(interactive)
(eldoc-mode 1))
-(defun eldoc-add-command (cmd)
- "Add COMMAND to the list of commands which causes function arg display.
-If called interactively, completion matches any bound function.
-
-When point is in a sexp, the function args are not reprinted in the echo
-area after every possible interactive command because some of them print
-their own messages in the echo area; the eldoc functions would instantly
-overwrite them unless it is more restrained."
- (interactive "aAdd function to eldoc message commands list: ")
- (and (fboundp cmd)
- (set (intern (symbol-name cmd) eldoc-mode-message-commands) t)))
-
-(defun eldoc-remove-command (cmd)
- "Remove COMMAND from the list of commands which causes function arg display.
-If called interactively, completion matches only those functions currently
-in the list.
-
-When point is in a sexp, the function args are not reprinted in the echo
-area after every possible interactive command because some of them print
-their own messages in the echo area; the eldoc functions would instantly
-overwrite them unless it is more restrained."
- (interactive (list (completing-read
- "Remove function from eldoc message commands list: "
- eldoc-mode-message-commands 'boundp t)))
- (and (symbolp cmd)
- (setq cmd (symbol-name cmd)))
- (if (fboundp 'unintern)
- (unintern cmd eldoc-mode-message-commands)
- (let ((s (intern-soft cmd eldoc-mode-message-commands)))
- (and s
- (makunbound s)))))
-
-(defun eldoc-mode-print-current-symbol-info ()
- (and eldoc-mode
- (not executing-macro)
- ;; Having this mode operate in the minibuffer makes it impossible to
- ;; see what you're doing.
- (not (eq (selected-window) (minibuffer-window)))
- (sit-for eldoc-idle-delay)
- (symbolp this-command)
- (intern-soft (symbol-name this-command) eldoc-mode-message-commands)
- (let ((current-symbol (eldoc-current-symbol))
- (current-fnsym (eldoc-fnsym-in-current-sexp)))
- (cond ((eq current-symbol current-fnsym)
- (eldoc-print-fnsym-args current-fnsym))
- (t
- (or (eldoc-print-var-docstring current-symbol)
- (eldoc-print-fnsym-args current-fnsym)))))))
-
\f
-(defun eldoc-print-var-docstring (&optional sym)
- "Print the brief (one-line) documentation string for the variable at point.
-If called with no argument, print the first line of the variable
-documentation string for the symbol at point in the echo area.
-If called with a symbol, print the line for that symbol.
-
-If the entire line cannot fit in the echo area, the variable name may be
-truncated or eliminated entirely from the output to make room.
-Any leading `*' in the docstring (which indicates the variable is a user
-option) is not printed."
- (interactive)
- (let* ((s (or sym (eldoc-current-symbol)))
- (name (symbol-name s))
- (doc (and s (documentation-property s 'variable-documentation t))))
- (and doc
- (save-match-data
- (and (string-match "\n" doc)
- (setq doc (substring doc 0 (match-beginning 0))))
- (and (string-match "^\\*" doc)
- (setq doc (substring doc 1)))
- (let* ((doclen (+ (length name) (length ": ") (length doc)))
- ;; Subtract 1 from window width since emacs seems not to
- ;; write any chars to the last column, at least for some
- ;; terminal types.
- (strip (- doclen (1- (window-width (minibuffer-window))))))
- (cond ((> strip 0)
- (let* ((len (length name)))
- (cond ((>= strip len)
- (eldoc-message "%s" doc))
- (t
- (setq name (substring name 0 (- len strip)))
- (eldoc-message "%s: %s" name doc)))))
- (t
- (eldoc-message "%s: %s" s doc))))
- t))))
+(defun eldoc-schedule-timer ()
+ (or (and eldoc-timer
+ (memq eldoc-timer timer-idle-list))
+ (setq eldoc-timer
+ (run-with-idle-timer eldoc-idle-delay t
+ 'eldoc-print-current-symbol-info)))
+
+ ;; If user has changed the idle delay, update the timer.
+ (cond ((not (= eldoc-idle-delay eldoc-current-idle-delay))
+ (setq eldoc-current-idle-delay eldoc-idle-delay)
+ (timer-set-idle-time eldoc-timer eldoc-idle-delay t))))
+
+(defun eldoc-message (&rest args)
+ (let ((omessage eldoc-last-message))
+ (setq eldoc-last-message
+ (cond ((eq (car args) eldoc-last-message) eldoc-last-message)
+ ((null (car args)) nil)
+ ;; If only one arg, no formatting to do, so put it in
+ ;; eldoc-last-message so eq test above might succeed on
+ ;; subsequent calls.
+ ((null (cdr args)) (car args))
+ (t (apply 'format args))))
+ ;; In emacs 19.29 and later, and XEmacs 19.13 and later, all messages
+ ;; are recorded in a log. Do not put eldoc messages in that log since
+ ;; they are Legion.
+ ;; Emacs way of preventing log messages.
+ (let ((message-log-max nil))
+ (cond (eldoc-last-message (message "%s" eldoc-last-message))
+ (omessage (message nil)))))
+ eldoc-last-message)
+
+;; This function goes on pre-command-hook for XEmacs or when using idle
+;; timers in Emacs. Motion commands clear the echo area for some reason,
+;; which make eldoc messages flicker or disappear just before motion
+;; begins. This function reprints the last eldoc message immediately
+;; before the next command executes, which does away with the flicker.
+;; This doesn't seem to be required for Emacs 19.28 and earlier.
+(defun eldoc-pre-command-refresh-echo-area ()
+ (and eldoc-last-message
+ (if (eldoc-display-message-no-interference-p)
+ (eldoc-message eldoc-last-message)
+ (setq eldoc-last-message nil))))
+
+;; Decide whether now is a good time to display a message.
+(defun eldoc-display-message-p ()
+ (and (eldoc-display-message-no-interference-p)
+ ;; If this-command is non-nil while running via an idle
+ ;; timer, we're still in the middle of executing a command,
+ ;; e.g. a query-replace where it would be annoying to
+ ;; overwrite the echo area.
+ (and (not this-command)
+ (symbolp last-command)
+ (intern-soft (symbol-name last-command)
+ eldoc-message-commands))))
+
+;; Check various conditions about the current environment that might make
+;; it undesirable to print eldoc messages right this instant.
+(defun eldoc-display-message-no-interference-p ()
+ (and eldoc-mode
+ (not executing-kbd-macro)
+ (not (and (boundp 'edebug-active) edebug-active))
+ ;; Having this mode operate in an active minibuffer/echo area causes
+ ;; interference with what's going on there.
+ (not cursor-in-echo-area)
+ (not (eq (selected-window) (minibuffer-window)))))
\f
;;;###autoload
-(defun eldoc-print-fnsym-args (&optional symbol)
- "*Show the defined parameters for the function near point.
-For the function at the beginning of the sexp which point is within, show
-the defined parameters for the function in the echo area.
-This information is extracted directly from the function or macro if it is
-in pure lisp.
-If the emacs function is a subr, the parameters are obtained from the
-documentation string if possible."
- (interactive)
- (let ((sym (or symbol (eldoc-fnsym-in-current-sexp)))
- (printit t)
- (args nil))
- (cond ((not (and (symbolp sym)
- (fboundp sym))))
- ((eq sym (car eldoc-last-data))
- (setq printit nil)
- (setq args (cdr eldoc-last-data)))
- ((subrp (eldoc-symbol-function sym))
- (setq args (eldoc-function-argstring-from-docstring sym))
- (setcdr eldoc-last-data args))
+(defvar eldoc-documentation-function nil
+ "If non-nil, function to call to return doc string.
+The function of no args should return a one-line string for displaying
+doc about a function etc. appropriate to the context around point.
+It should return nil if there's no doc appropriate for the context.
+Typically doc is returned if point is on a function-like name or in its
+arg list.
+
+This variable is expected to be made buffer-local by modes (other than
+Emacs Lisp mode) that support Eldoc.")
+
+(defun eldoc-print-current-symbol-info ()
+ (condition-case err
+ (and (eldoc-display-message-p)
+ (if eldoc-documentation-function
+ (eldoc-message (funcall eldoc-documentation-function))
+ (let* ((current-symbol (eldoc-current-symbol))
+ (current-fnsym (eldoc-fnsym-in-current-sexp))
+ (doc (cond
+ ((eq current-symbol current-fnsym)
+ (or (eldoc-get-fnsym-args-string current-fnsym)
+ (eldoc-get-var-docstring current-symbol)))
+ (t
+ (or (eldoc-get-var-docstring current-symbol)
+ (eldoc-get-fnsym-args-string current-fnsym))))))
+ (eldoc-message doc))))
+ ;; This is run from post-command-hook or some idle timer thing,
+ ;; so we need to be careful that errors aren't ignored.
+ (error (message "eldoc error: %s" err))))
+
+;; Return a string containing the function parameter list, or 1-line
+;; docstring if function is a subr and no arglist is obtainable from the
+;; docstring or elsewhere.
+(defun eldoc-get-fnsym-args-string (sym)
+ (let ((args nil)
+ (doc nil))
+ (cond ((not (and sym (symbolp sym) (fboundp sym))))
+ ((and (eq sym (aref eldoc-last-data 0))
+ (eq 'function (aref eldoc-last-data 2)))
+ (setq doc (aref eldoc-last-data 1)))
+ ((setq doc (help-split-fundoc (documentation sym t) sym))
+ (setq args (car doc))
+ (string-match "\\`[^ )]* ?" args)
+ (setq args (concat "(" (substring args (match-end 0)))))
(t
- (setq args (eldoc-function-argstring sym))
- (setcdr eldoc-last-data args)))
- (and args
- printit
- (eldoc-message "%s: %s" sym args))))
+ (setq args (eldoc-function-argstring sym))))
+ (cond (args
+ (setq doc (eldoc-docstring-format-sym-doc sym args))
+ (eldoc-last-data-store sym doc 'function)))
+ doc))
+
+;; Return a string containing a brief (one-line) documentation string for
+;; the variable.
+(defun eldoc-get-var-docstring (sym)
+ (when sym
+ (cond ((and (eq sym (aref eldoc-last-data 0))
+ (eq 'variable (aref eldoc-last-data 2)))
+ (aref eldoc-last-data 1))
+ (t
+ (let ((doc (documentation-property sym 'variable-documentation t)))
+ (cond (doc
+ (setq doc (eldoc-docstring-format-sym-doc
+ sym (eldoc-docstring-first-line doc)))
+ (eldoc-last-data-store sym doc 'variable)))
+ doc)))))
+
+(defun eldoc-last-data-store (symbol doc type)
+ (aset eldoc-last-data 0 symbol)
+ (aset eldoc-last-data 1 doc)
+ (aset eldoc-last-data 2 type))
+
+;; Note that any leading `*' in the docstring (which indicates the variable
+;; is a user option) is removed.
+(defun eldoc-docstring-first-line (doc)
+ (and (stringp doc)
+ (substitute-command-keys
+ (save-match-data
+ (let ((start (if (string-match "^\\*" doc) (match-end 0) 0)))
+ (cond ((string-match "\n" doc)
+ (substring doc start (match-beginning 0)))
+ ((zerop start) doc)
+ (t (substring doc start))))))))
+
+;; If the entire line cannot fit in the echo area, the symbol name may be
+;; truncated or eliminated entirely from the output to make room for the
+;; description.
+(defun eldoc-docstring-format-sym-doc (sym doc)
+ (save-match-data
+ (let* ((name (symbol-name sym))
+ (ea-multi eldoc-echo-area-use-multiline-p)
+ ;; Subtract 1 from window width since emacs will not write
+ ;; any chars to the last column, or in later versions, will
+ ;; cause a wraparound and resize of the echo area.
+ (ea-width (1- (window-width (minibuffer-window))))
+ (strip (- (+ (length name) (length ": ") (length doc)) ea-width)))
+ (cond ((or (<= strip 0)
+ (eq ea-multi t)
+ (and ea-multi (> (length doc) ea-width)))
+ (format "%s: %s" sym doc))
+ ((> (length doc) ea-width)
+ (substring (format "%s" doc) 0 ea-width))
+ ((>= strip (length name))
+ (format "%s" doc))
+ (t
+ ;; Show the end of the partial symbol name, rather
+ ;; than the beginning, since the former is more likely
+ ;; to be unique given package namespace conventions.
+ (setq name (substring name strip))
+ (format "%s: %s" name doc))))))
+\f
(defun eldoc-fnsym-in-current-sexp ()
- (let* ((p (point))
- (sym (progn
- (while (and (eldoc-forward-sexp-safe -1)
- (> (point) (point-min))))
- (cond ((or (= (point) (point-min))
- (memq (or (char-after (point)) 0)
- '(?\( ?\"))
- ;; If we hit a quotation mark before a paren, we
- ;; are inside a specific string, not a list of
- ;; symbols.
- (eq (or (char-after (1- (point))) 0) ?\"))
- nil)
- (t (condition-case nil
- (read (current-buffer))
- (error nil)))))))
- (goto-char p)
- (and (symbolp sym)
- sym)))
+ (let ((p (point)))
+ (eldoc-beginning-of-sexp)
+ (prog1
+ ;; Don't do anything if current word is inside a string.
+ (if (= (or (char-after (1- (point))) 0) ?\")
+ nil
+ (eldoc-current-symbol))
+ (goto-char p))))
+
+(defun eldoc-beginning-of-sexp ()
+ (let ((parse-sexp-ignore-comments t))
+ (condition-case err
+ (while (progn
+ (forward-sexp -1)
+ (or (= (char-before) ?\")
+ (> (point) (point-min)))))
+ (error nil))))
+
+;; returns nil unless current word is an interned symbol.
+(defun eldoc-current-symbol ()
+ (let ((c (char-after (point))))
+ (and c
+ (memq (char-syntax c) '(?w ?_))
+ (intern-soft (current-word)))))
+
+;; Do indirect function resolution if possible.
+(defun eldoc-symbol-function (fsym)
+ (let ((defn (and (fboundp fsym)
+ (symbol-function fsym))))
+ (and (symbolp defn)
+ (condition-case err
+ (setq defn (indirect-function fsym))
+ (error (setq defn nil))))
+ defn))
(defun eldoc-function-argstring (fn)
- (let* ((prelim-def (eldoc-symbol-function fn))
- (def (if (eq (car-safe prelim-def) 'macro)
- (cdr prelim-def)
- prelim-def))
- (arglist (cond ((null def) nil)
- ((byte-code-function-p def)
- (if (fboundp 'compiled-function-arglist)
- (funcall 'compiled-function-arglist def)
- (aref def 0)))
- ((eq (car-safe def) 'lambda)
- (nth 1 def))
- (t t))))
- (eldoc-function-argstring-format arglist)))
-
-(defun eldoc-function-argstring-from-docstring (fn)
- (let ((docstring (documentation fn 'raw))
- (doc nil)
- (doclist nil)
- (end nil))
- (save-match-data
- ;; TODO: Move these into a separate table that is iterated over until
- ;; a match is found.
- (cond
- ;; Try first searching for args starting with symbol name.
- ;; This is to avoid matching parenthetical remarks in e.g. sit-for.
- ((string-match (format "^(%s[^\n)]*)$" fn) docstring)
- ;; end does not include trailing ")" sequence.
- (setq end (- (match-end 0) 1))
- (if (string-match " +" docstring (match-beginning 0))
- (setq doc (substring docstring (match-end 0) end))
- (setq doc "")))
-
- ;; Try again not requiring this symbol name in the docstring.
- ;; This will be the case when looking up aliases.
- ((string-match (format "^([^\n)]+)$" fn) docstring)
- ;; end does not include trailing ")" sequence.
- (setq end (- (match-end 0) 1))
- (if (string-match " +" docstring (match-beginning 0))
- (setq doc (substring docstring (match-end 0) end))
- (setq doc "")))
-
- ;; Emacs subr docstring style:
- ;; (fn arg1 arg2 ...): description...
- ((string-match "^([^\n)]+):" docstring)
- ;; end does not include trailing "):" sequence.
- (setq end (- (match-end 0) 2))
- (if (string-match " +" docstring (match-beginning 0))
- (setq doc (substring docstring (match-end 0) end))
- (setq doc "")))
-
- ;; XEmacs subr docstring style:
- ;; "arguments: (arg1 arg2 ...)
- ((string-match "^arguments: (\\([^\n)]+\\))" docstring)
- ;; Also, skip leading paren, but the first word is actually an
- ;; argument, not the function name.
- (setq doc (substring docstring
- (match-beginning 1)
- (match-end 1))))
-
- ;; This finds the argstring for `condition-case'.
- ;; I don't know if there are any others with the same pattern.
- ((string-match (format "^Usage looks like \\((%s[^\n)]*)\\)\\.$" fn)
- docstring)
- ;; end does not include trailing ")" sequence.
- (setq end (- (match-end 1) 1))
- (if (string-match " +" docstring (match-beginning 1))
- (setq doc (substring docstring (match-end 0) end))
- (setq doc "")))
-
- ;; This finds the argstring for `setq-default'.
- ;; I don't know if there are any others with the same pattern.
- ((string-match (format "^[ \t]+\\((%s[^\n)]*)\\)$" fn) docstring)
- ;; end does not include trailing ")" sequence.
- (setq end (- (match-end 1) 1))
- (if (string-match " +" docstring (match-beginning 1))
- (setq doc (substring docstring (match-end 0) end))
- (setq doc "")))
-
- ;; This finds the argstring for `start-process'.
- ;; I don't know if there are any others with the same pattern.
- ((string-match "^Args are +\\([^\n]+\\)$" docstring)
- (setq doc (substring docstring (match-beginning 1) (match-end 1))))
- )
-
- (cond ((not (stringp doc))
- nil)
- ((string-match "&" doc)
- (let ((p 0)
- (l (length doc)))
- (while (< p l)
- (cond ((string-match "[ \t\n]+" doc p)
- (setq doclist
- (cons (substring doc p (match-beginning 0))
- doclist))
- (setq p (match-end 0)))
- (t
- (setq doclist (cons (substring doc p) doclist))
- (setq p l))))
- (eldoc-function-argstring-format (nreverse doclist))))
- (t
- (concat "(" (funcall eldoc-argument-case doc) ")"))))))
+ (eldoc-function-argstring-format (help-function-arglist fn)))
(defun eldoc-function-argstring-format (arglist)
(cond ((not (listp arglist))
(concat "(" (mapconcat 'identity arglist " ") ")"))
\f
-;; forward-sexp calls scan-sexps, which returns an error if it hits the
-;; beginning or end of the sexp. This returns nil instead.
-(defun eldoc-forward-sexp-safe (&optional count)
- "Move forward across one balanced expression (sexp).
-With argument, do it that many times. Negative arg -COUNT means
-move backward across COUNT balanced expressions.
-Return distance in buffer moved, or nil."
- (or count (setq count 1))
- (condition-case err
- (- (- (point) (progn
- (let ((parse-sexp-ignore-comments t))
- (forward-sexp count))
- (point))))
- (error nil)))
-
-;; Do indirect function resolution if possible.
-(defun eldoc-symbol-function (fsym)
- (let ((defn (and (fboundp fsym)
- (symbol-function fsym))))
- (and (symbolp defn)
- (condition-case err
- (setq defn (indirect-function fsym))
- (error (setq defn nil))))
- defn))
+;; When point is in a sexp, the function args are not reprinted in the echo
+;; area after every possible interactive command because some of them print
+;; their own messages in the echo area; the eldoc functions would instantly
+;; overwrite them unless it is more restrained.
+;; These functions do display-command table management.
+
+(defun eldoc-add-command (&rest cmds)
+ (dolist (name cmds)
+ (and (symbolp name)
+ (setq name (symbol-name name)))
+ (set (intern name eldoc-message-commands) t)))
+
+(defun eldoc-add-command-completions (&rest names)
+ (dolist (name names)
+ (apply 'eldoc-add-command (all-completions name obarray 'commandp))))
+
+(defun eldoc-remove-command (&rest cmds)
+ (dolist (name cmds)
+ (and (symbolp name)
+ (setq name (symbol-name name)))
+ (unintern name eldoc-message-commands)))
+
+(defun eldoc-remove-command-completions (&rest names)
+ (dolist (name names)
+ (apply 'eldoc-remove-command
+ (all-completions name eldoc-message-commands))))
-(defun eldoc-current-symbol ()
- (let ((c (char-after (point))))
- (and c
- (memq (char-syntax c) '(?w ?_))
- (intern-soft (current-word)))))
+\f
+;; Prime the command list.
+(eldoc-add-command-completions
+ "backward-" "beginning-of-" "move-beginning-of-" "delete-other-windows"
+ "delete-window"
+ "end-of-" "move-end-of-" "exchange-point-and-mark" "forward-"
+ "indent-for-tab-command" "goto-" "mark-page" "mark-paragraph"
+ "mouse-set-point" "move-" "pop-global-mark" "next-" "other-window"
+ "previous-" "recenter" "scroll-" "self-insert-command"
+ "split-window-" "up-list" "down-list")
(provide 'eldoc)
+;; arch-tag: c9a58f9d-2055-46c1-9b82-7248b71a8375
;;; eldoc.el ends here