;;; eldoc.el --- show function arglist or variable docstring in echo area
-;; Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+;; 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
;; Created: 1995-10-06
-;; $Id: eldoc.el,v 1.8 1997/02/03 06:13:34 friedman Exp $
-
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; 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:
-
-;; Use idle timers if available in the version of emacs running.
-;; Please don't change this to use `require'; this package works as-is in
-;; XEmacs (which doesn't have timer.el as of 19.14), and I would like to
-;; maintain compatibility with that since I must use it sometimes. --Noah
-(or (featurep 'timer)
- (load "timer" t))
-
-;;;###autoload
-(defvar eldoc-mode nil
- "*If non-nil, show the defined parameters for the elisp function near point.
+;; Major modes for other languages may use Eldoc by defining an
+;; appropriate function as the buffer-local value of
+;; `eldoc-documentation-function'.
-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. 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.
+(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)
-(defconst 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.")
-
-(defconst eldoc-minor-mode-string " ElDoc"
- "*String to display in mode line when Eldoc Mode is enabled.")
+If this variable is set to 0, no idle time is required."
+ :type 'number
+ :group 'eldoc)
-;; 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)))))
+;;;###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)
-(defconst eldoc-argument-case 'upcase
+(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-message-commands nil
- "*Commands after which it is appropriate to print in the echo area.
-
+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)
-This variable contains an obarray of symbols; it is probably best to
-manipulate this data structure with the commands `eldoc-add-command' and
-`eldoc-remove-command'.")
-
-(cond ((null eldoc-message-commands)
- ;; If you increase the number of buckets, keep it a prime number.
- (setq eldoc-message-commands (make-vector 31 0))
- (let ((list '("self-insert-command"
- "next-" "previous-"
- "forward-" "backward-"
- "beginning-of-" "end-of-"
- "goto-"
- "recenter"
- "scroll-"
- "mouse-set-point"))
- (syms nil))
- (while list
- (setq syms (all-completions (car list) obarray 'fboundp))
- (setq list (cdr list))
- (while syms
- (set (intern (car syms) eldoc-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))
-
-;; Idle timers are supported in Emacs 19.31 and later.
-(defconst eldoc-use-idle-timer-p (fboundp 'run-with-idle-timer))
-
-;; eldoc's timer object, if using idle timers
-(defvar eldoc-timer nil)
-
-;; idle time delay currently in use by timer.
-;; This is used to determine if eldoc-idle-delay is changed by the user.
-(defvar eldoc-current-idle-delay eldoc-idle-delay)
-
-;; 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))))
+(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)
- "*Enable or disable eldoc mode.
-See documentation for the variable of the same name for more details.
-
-If called interactively with no prefix argument, toggle current condition
-of the mode.
-If called with a positive or negative prefix argument, enable or disable
-the mode, respectively."
- (interactive "P")
-
- (cond (eldoc-use-idle-timer-p
- (add-hook 'post-command-hook 'eldoc-schedule-timer))
- (t
- ;; Use post-command-idle-hook if defined, otherwise use
- ;; post-command-hook. The former is only proper to use in Emacs
- ;; 19.30; that is the first version in which it appeared, but it
- ;; was obsolesced by idle timers in Emacs 19.31.
- (add-hook (if (boundp 'post-command-idle-hook)
- 'post-command-idle-hook
- 'post-command-hook)
- 'eldoc-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 on defined commands is available.
-
-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 "CAdd function to eldoc message commands list: ")
- (and (fboundp cmd)
- (set (intern (symbol-name cmd) eldoc-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-message-commands 'boundp t)))
- (and (symbolp cmd)
- (setq cmd (symbol-name cmd)))
- (if (fboundp 'unintern)
- (unintern cmd eldoc-message-commands)
- (let ((s (intern-soft cmd eldoc-message-commands)))
- (and s
- (makunbound s)))))
-
-;; Idle timers are part of Emacs 19.31 and later.
+\f
(defun eldoc-schedule-timer ()
(or (and eldoc-timer
(memq eldoc-timer timer-idle-list))
(setq eldoc-current-idle-delay eldoc-idle-delay)
(timer-set-idle-time eldoc-timer eldoc-idle-delay t))))
-\f
-(defun eldoc-print-current-symbol-info ()
- (and (eldoc-display-message-p)
- (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)))))))
+(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)))
-
- (cond (eldoc-use-idle-timer-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)))
- (t
- ;; If we don't have idle timers, this function is
- ;; running on post-command-hook directly; that means the
- ;; user's last command is still on `this-command', and we
- ;; must wait briefly for input to see whether to do display.
- (and (symbolp this-command)
- (intern-soft (symbol-name this-command)
- eldoc-message-commands)
- (sit-for eldoc-idle-delay))))))
-
-(defun eldoc-print-fnsym-args (&optional symbol)
- (interactive)
- (let ((sym (or symbol (eldoc-fnsym-in-current-sexp)))
- (args nil))
- (cond ((not (and (symbolp sym)
- (fboundp sym))))
- ((eq sym (car eldoc-last-data))
- (setq args (cdr eldoc-last-data)))
- ((subrp (eldoc-symbol-function sym))
- (setq args (or (eldoc-function-argstring-from-docstring sym)
- (eldoc-docstring-first-line (documentation sym t))))
- (setcar eldoc-last-data sym)
- (setcdr eldoc-last-data args))
+ (not (eq (selected-window) (minibuffer-window)))))
+
+\f
+;;;###autoload
+(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))
- (setcar eldoc-last-data sym)
- (setcdr eldoc-last-data args)))
- (and args
- (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)))
+ (eldoc-function-argstring-format (help-function-arglist fn)))
(defun eldoc-function-argstring-format (arglist)
(cond ((not (listp arglist))
(concat "(" (mapconcat 'identity arglist " ") ")"))
\f
-(defun eldoc-print-var-docstring (&optional sym)
- (or sym (setq sym (eldoc-current-symbol)))
- (eldoc-print-docstring sym (documentation-property
- sym 'variable-documentation t)))
-
-;; Print the brief (one-line) documentation string for the symbol.
-(defun eldoc-print-docstring (symbol doc)
- (and doc
- (eldoc-message "%s" (eldoc-docstring-message symbol doc))))
-
-;; 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."
-(defun eldoc-docstring-message (symbol doc)
- (and doc
- (let ((name (symbol-name symbol)))
- (setq doc (eldoc-docstring-first-line doc))
- (save-match-data
- (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)
- (format "%s" doc))
- (t
- (setq name (substring name 0 (- len strip)))
- (format "%s: %s" name doc)))))
- (t
- (format "%s: %s" symbol doc))))))))
-
-(defun eldoc-docstring-first-line (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))))
- doc)
-
-\f
-;; Alist of predicate/action pairs.
-;; Each member of the list is a sublist consisting of a predicate function
-;; used to determine if the arglist for a function can be found using a
-;; certain pattern, and a function which returns the actual arglist from
-;; that docstring.
-;;
-;; The order in this table is significant, since later predicates may be
-;; more general than earlier ones.
-;;
-;; Compiler note for Emacs 19.29 and later: these functions will be
-;; compiled to bytecode, but can't be lazy-loaded even if you set
-;; byte-compile-dynamic; to do that would require making them named
-;; top-level defuns, and that's not particularly desirable either.
-(defconst eldoc-function-argstring-from-docstring-method-table
- (list
- ;; Try first searching for args starting with symbol name.
- ;; This is to avoid matching parenthetical remarks in e.g. sit-for.
- (list (function (lambda (doc fn)
- (string-match (format "^(%s[^\n)]*)$" fn) doc)))
- (function (lambda (doc)
- ;; end does not include trailing ")" sequence.
- (let ((end (- (match-end 0) 1)))
- (if (string-match " +" doc (match-beginning 0))
- (substring doc (match-end 0) end)
- "")))))
-
- ;; Try again not requiring this symbol name in the docstring.
- ;; This will be the case when looking up aliases.
- (list (function (lambda (doc fn)
- (string-match "^([^\n)]+)$" doc)))
- (function (lambda (doc)
- ;; end does not include trailing ")" sequence.
- (let ((end (- (match-end 0) 1)))
- (and (string-match " +" doc (match-beginning 0))
- (substring doc (match-end 0) end))))))
-
- ;; Emacs subr docstring style:
- ;; (fn arg1 arg2 ...): description...
- (list (function (lambda (doc fn)
- (string-match "^([^\n)]+):" doc)))
- (function (lambda (doc)
- ;; end does not include trailing "):" sequence.
- (let ((end (- (match-end 0) 2)))
- (and (string-match " +" doc (match-beginning 0))
- (substring doc (match-end 0) end))))))
-
- ;; XEmacs subr docstring style:
- ;; "arguments: (arg1 arg2 ...)
- (list (function (lambda (doc fn)
- (string-match "^arguments: (\\([^\n)]+\\))" doc)))
- (function (lambda (doc)
- ;; also skip leading paren, but the first word is
- ;; actually an argument, not the function name.
- (substring doc (match-beginning 1) (match-end 1)))))
-
- ;; This finds the argstring for `condition-case'. Any others?
- (list (function (lambda (doc fn)
- (string-match
- (format "^Usage looks like \\((%s[^\n)]*)\\)\\.$" fn)
- doc)))
- (function (lambda (doc)
- ;; end does not include trailing ")" sequence.
- (let ((end (- (match-end 1) 1)))
- (and (string-match " +" doc (match-beginning 1))
- (substring doc (match-end 0) end))))))
-
- ;; This finds the argstring for `setq-default'. Any others?
- (list (function (lambda (doc fn)
- (string-match (format "^[ \t]+\\((%s[^\n)]*)\\)$" fn)
- doc)))
- (function (lambda (doc)
- ;; end does not include trailing ")" sequence.
- (let ((end (- (match-end 1) 1)))
- (and (string-match " +" doc (match-beginning 1))
- (substring doc (match-end 0) end))))))
-
- ;; This finds the argstring for `start-process'. Any others?
- (list (function (lambda (doc fn)
- (string-match "^Args are +\\([^\n]+\\)$" doc)))
- (function (lambda (doc)
- (substring doc (match-beginning 1) (match-end 1)))))
- ))
-
-(defun eldoc-function-argstring-from-docstring (fn)
- (let ((docstring (documentation fn 'raw))
- (table eldoc-function-argstring-from-docstring-method-table)
- (doc nil)
- (doclist nil))
- (save-match-data
- (while table
- (cond ((funcall (car (car table)) docstring fn)
- (setq doc (funcall (car (cdr (car table))) docstring))
- (setq table nil))
- (t
- (setq table (cdr table)))))
-
- (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) ")"))))))
+;; 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))))
\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))
-
-(defun eldoc-current-symbol ()
- (let ((c (char-after (point))))
- (and c
- (memq (char-syntax c) '(?w ?_))
- (intern-soft (current-word)))))
+;; 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