X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/582b6241efe64b45aa8747a9dc2557c730ac889a..e1483c383115cc874a07ce2353567125ec36941f:/lisp/help.el diff --git a/lisp/help.el b/lisp/help.el index ba3c6d6d4c..aa3e7c42e3 100644 --- a/lisp/help.el +++ b/lisp/help.el @@ -1,6 +1,6 @@ ;;; 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 @@ -25,13 +25,14 @@ ;;; 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.") @@ -82,6 +83,8 @@ (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) @@ -101,31 +104,13 @@ ;; 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'. -An element looks like (POSITION FUNCTION ARGS...). -To use the element, do (apply FUNCTION ARGS) then (goto-char POSITION).") +An element looks like (POSITION FUNCTION ARGS...), where POSITION is +`(POINT . BUFFER-NAME)'. +To use the element, do (apply FUNCTION ARGS) then goto the point in +the named buffer.") (put 'help-xref-stack 'permanent-local t) (defvar help-xref-stack-item nil @@ -135,6 +120,11 @@ The format is (FUNCTION ARGS...).") (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'. @@ -154,10 +144,14 @@ Commands: ;; `help-mode-maybe'. (run-hooks 'help-mode-hook)) -(defun help-mode-maybe () - (if (eq major-mode 'fundamental-mode) - (help-mode)) - (when (eq major-mode 'help-mode) +(defun help-mode-setup () + (help-mode) + (setq buffer-read-only nil)) + +(add-hook 'temp-buffer-setup-hook 'help-mode-setup) + +(defun help-mode-finish () + (when (eq major-mode 'help-mode) ;; View mode's read-only status of existing *Help* buffer is lost ;; by with-output-to-temp-buffer. (toggle-read-only 1) @@ -165,9 +159,10 @@ Commands: (setq view-return-to-alist (list (cons (selected-window) help-return-method)))) -(add-hook 'temp-buffer-show-hook 'help-mode-maybe) +(add-hook 'temp-buffer-show-hook 'help-mode-finish) (defun help-quit () + "Just exit from the Help command's command loop." (interactive) nil) @@ -211,6 +206,19 @@ With arg, you are asked to choose which language." (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." @@ -231,7 +239,8 @@ 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)) @@ -265,6 +274,10 @@ If FUNCTION is nil, applies `message' to it, thus printing it." ;; Secondly, the buffer has not been displayed yet, ;; so we don't know whether its frame will be selected. nil) + (display-buffer-reuse-frames + (setq help-return-method (cons (selected-window) + 'quit-window)) + nil) ((not (one-window-p t)) (setq help-return-method (cons (selected-window) 'quit-window)) @@ -280,9 +293,8 @@ If FUNCTION is nil, applies `message' to it, thus printing it." (funcall (or function 'message) (concat (if first-message - (substitute-command-keys first-message) - "") - (if first-message " " "") + (substitute-command-keys first-message)) + (if first-message " ") ;; If the help buffer will go in a separate frame, ;; it's no use mentioning a command to scroll, so don't. (if (special-display-p (buffer-name standard-output)) @@ -312,7 +324,7 @@ If FUNCTION is nil, applies `message' to it, thus printing it." (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*" @@ -322,25 +334,35 @@ If FUNCTION is nil, applies `message' to it, thus printing it." (princ " runs the command ") (prin1 defn) (princ "\n which is ") - (describe-function-1 defn nil) + (describe-function-1 defn nil (interactive-p)) (print-help-return-message))))))) (defun describe-mode () "Display documentation of current major mode and minor modes. +The major mode description comes first, followed by the minor modes, +each on a separate page. + For this to work correctly for a minor mode, the mode's indicator variable \(listed in `minor-mode-alist') must also be a function whose documentation describes the minor mode." (interactive) (with-output-to-temp-buffer "*Help*" - (let ((minor-modes minor-mode-alist) - (first t)) + (when minor-mode-alist + (princ "The major mode is described first. +For minor modes, see following pages.\n\n")) + (princ mode-name) + (princ " mode:\n") + (princ (documentation major-mode)) + (help-setup-xref (list #'help-xref-mode (current-buffer)) (interactive-p)) + (let ((minor-modes minor-mode-alist)) (while minor-modes (let* ((minor-mode (car (car minor-modes))) (indicator (car (cdr (car minor-modes))))) ;; Document a minor mode if it is listed in minor-mode-alist, ;; bound locally in this buffer, non-nil, and has a function ;; definition. - (if (and (symbol-value minor-mode) + (if (and (boundp minor-mode) + (symbol-value minor-mode) (fboundp minor-mode)) (let ((pretty-minor-mode minor-mode)) (if (string-match "-mode$" (symbol-name minor-mode)) @@ -348,24 +370,18 @@ describes the minor mode." (capitalize (substring (symbol-name minor-mode) 0 (match-beginning 0))))) - (while (and indicator (symbolp indicator)) + (while (and indicator (symbolp indicator) + (boundp indicator) + (not (eq indicator (symbol-value indicator)))) (setq indicator (symbol-value indicator))) - (if first - (princ "The minor modes are described first, -followed by the major mode, which is described on the last page.\n\f\n")) - (setq first nil) + (princ "\n\f\n") (princ (format "%s minor mode (%s):\n" pretty-minor-mode (if indicator (format "indicator%s" indicator) "no indicator"))) - (princ (documentation minor-mode)) - (princ "\n\f\n")))) + (princ (documentation minor-mode))))) (setq minor-modes (cdr minor-modes)))) - (princ mode-name) - (princ " mode:\n") - (princ (documentation major-mode)) - (help-setup-xref (list #'help-xref-mode (current-buffer)) (interactive-p)) (print-help-return-message))) ;; So keyboard macro definitions are documented correctly @@ -420,17 +436,30 @@ of the key sequence that ran this command." (defun view-emacs-news (&optional arg) "Display info on recent changes to Emacs. -With numeric argument display information on correspondingly older changes." +With numeric argument, display information on correspondingly older changes." (interactive "P") - (let* ((arg (if arg (prefix-numeric-value arg) 0))) - (find-file-read-only - (expand-file-name (concat (make-string arg ?O) "NEWS") - data-directory)))) + (let* ((arg (if arg (prefix-numeric-value arg) 0)) + (file (cond ((eq arg 0) "NEWS") + ((eq arg 1) "ONEWS") + (t + (nth (- arg 2) + (nreverse (directory-files data-directory + nil "^NEWS\\.[0-9]+$" + nil))))))) + (if file + (find-file-read-only (expand-file-name file data-directory)) + (error "No such old news")))) (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 "(efaq)")) + +(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." @@ -457,7 +486,7 @@ With numeric argument display information on correspondingly older changes." (defalias 'help 'help-for-help) (make-help-screen help-for-help "a b c C f F C-f i I k C-k l L m n p s t v w C-c C-d C-n C-p C-w; ? for help:" - "You have typed \\[help-command], the help character. Type a Help option: + "You have typed %THIS-KEY%, the help character. Type a Help option: \(Use SPC or DEL to scroll through this text. Type \\\\[help-quit] to exit the Help command.) a command-apropos. Give a substring, and see a list of commands @@ -475,17 +504,19 @@ C-f Info-goto-emacs-command-node. Type a function name; 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. @@ -503,41 +534,57 @@ C-p Display information about the GNU project. C-w Display information on absence of warranty for GNU Emacs." help-map) -;; Return a function which is called by the list containing point. -;; If that gives no function, return a function whose name is around point. -;; If that doesn't give a function, return nil. (defun function-called-at-point () - (let ((stab (syntax-table))) - (set-syntax-table emacs-lisp-mode-syntax-table) - (unwind-protect - (or (condition-case () - (save-excursion - (save-restriction - (narrow-to-region (max (point-min) (- (point) 1000)) (point-max)) - ;; Move up to surrounding paren, then after the open. - (backward-up-list 1) - (forward-char 1) - ;; If there is space here, this is probably something - ;; other than a real Lisp function call, so ignore it. - (if (looking-at "[ \t]") - (error "Probably not a Lisp function call")) - (let (obj) - (setq obj (read (current-buffer))) - (and (symbolp obj) (fboundp obj) obj)))) - (error nil)) - (condition-case () - (save-excursion - (or (not (zerop (skip-syntax-backward "_w"))) - (eq (char-syntax (following-char)) ?w) - (eq (char-syntax (following-char)) ?_) - (forward-sexp -1)) - (skip-chars-forward "'") - (let ((obj (read (current-buffer)))) - (and (symbolp obj) (fboundp obj) obj))) - (error nil))) - (set-syntax-table stab)))) - -(defun describe-function-find-file (function) + "Return a function around point or else called by the list containing point. +If that doesn't give a function, return nil." + (with-syntax-table emacs-lisp-mode-syntax-table + (or (condition-case () + (save-excursion + (or (not (zerop (skip-syntax-backward "_w"))) + (eq (char-syntax (following-char)) ?w) + (eq (char-syntax (following-char)) ?_) + (forward-sexp -1)) + (skip-chars-forward "'") + (let ((obj (read (current-buffer)))) + (and (symbolp obj) (fboundp obj) obj))) + (error nil)) + (condition-case () + (save-excursion + (save-restriction + (narrow-to-region (max (point-min) + (- (point) 1000)) (point-max)) + ;; Move up to surrounding paren, then after the open. + (backward-up-list 1) + (forward-char 1) + ;; If there is space here, this is probably something + ;; other than a real Lisp function call, so ignore it. + (if (looking-at "[ \t]") + (error "Probably not a Lisp function call")) + (let ((obj (read (current-buffer)))) + (and (symbolp obj) (fboundp obj) obj)))) + (error nil))))) + +(defvar symbol-file-load-history-loaded nil + "Non-nil means we have loaded the file `fns-VERSION.el' in `exec-directory'. +That file records the part of `load-history' for preloaded files, +which is cleared out before dumping to make Emacs smaller.") + +(defun symbol-file (function) + "Return the input source from which FUNCTION was loaded. +The value is normally a string that was passed to `load': +either an absolute file name, or a library name +\(with no directory name and no `.el' or `.elc' at the end). +It can also be nil, if the definition is not associated with any file." + (unless symbol-file-load-history-loaded + (load (expand-file-name + ;; fns-XX.YY.ZZ.el does not work on DOS filesystem. + (if (eq system-type 'ms-dos) + "fns.el" + (format "fns-%s.el" emacs-version)) + exec-directory) + ;; The file name fns-%s.el already has a .el extension. + nil nil t) + (setq symbol-file-load-history-loaded t)) (let ((files load-history) file functions) (while files @@ -564,7 +611,7 @@ C-w Display information on absence of warranty for GNU Emacs." ;; Use " is " instead of a colon so that ;; it is easier to get out the function name using forward-sexp. (princ " is ") - (describe-function-1 function nil) + (describe-function-1 function nil (interactive-p)) (print-help-return-message) (save-excursion (set-buffer standard-output) @@ -572,8 +619,10 @@ C-w Display information on absence of warranty for GNU Emacs." (buffer-string))) (message "You didn't specify a function"))) -(defun describe-function-1 (function parens) - (let* ((def (symbol-function function)) +(defun describe-function-1 (function parens interactive-p) + (let* ((def (if (symbolp function) + (symbol-function function) + function)) file-name string need-close (beg (if (commandp def) "an interactive " "a "))) (setq string @@ -581,11 +630,15 @@ C-w Display information on absence of warranty for GNU Emacs." (vectorp def)) "a keyboard macro") ((subrp def) - (concat beg "built-in function")) + (if (eq 'unevalled (cdr (subr-arity def))) + (concat beg "special form") + (concat beg "built-in function"))) ((byte-code-function-p def) (concat beg "compiled Lisp function")) ((symbolp def) - (format "alias for `%s'" def)) + (while (symbolp (symbol-function def)) + (setq def (symbol-function def))) + (format "an alias for `%s'" def)) ((eq (car-safe def) 'lambda) (concat beg "Lisp function")) ((eq (car-safe def) 'macro) @@ -594,17 +647,36 @@ C-w Display information on absence of warranty for GNU Emacs." "a mocklisp function") ((eq (car-safe def) 'autoload) (setq file-name (nth 1 def)) - (format "%s autoloaded Lisp %s" + (format "%s autoloaded %s" (if (commandp def) "an interactive" "an") - (if (nth 4 def) "macro" "function") + (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) (princ "(")) (princ string) + (with-current-buffer "*Help*" + (save-excursion + (save-match-data + (if (re-search-backward "alias for `\\([^`']+\\)'" nil t) + (help-xref-button 1 #'describe-function def + "mouse-2, RET: describe this function"))))) (or file-name - (setq file-name (describe-function-find-file function))) + (setq file-name (symbol-file function))) (if file-name (progn (princ " in `") @@ -621,130 +693,236 @@ C-w Display information on absence of warranty for GNU Emacs." (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) - (let* ((inner-function (if (and (listp def) 'macro) - (cdr def) - def)) - (arglist (cond ((byte-code-function-p inner-function) - (car (append inner-function nil))) - ((eq (car-safe inner-function) 'lambda) - (nth 1 inner-function)) - (t t)))) - (if (listp arglist) - (progn - (princ (cons function - (mapcar (lambda (arg) - (if (memq arg '(&optional &rest)) - arg - (intern (upcase (symbol-name arg))))) - arglist))) - (terpri)))) + ;; Handle symbols aliased to other symbols. + (setq def (indirect-function def)) + ;; If definition is a macro, find the function inside it. + (if (eq (car-safe def) 'macro) + (setq def (cdr def))) + (let ((arglist (cond ((byte-code-function-p def) + (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)))) + (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))) + (if (subrp (symbol-function function)) + (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. + + ;; In cases where `function' has been fset to a + ;; subr we can't search for function's name in + ;; the doc string. Kluge round that using the + ;; printed representation. The arg list then + ;; shows the wrong function name, but that + ;; might be a useful hint. + (let* ((rep (prin1-to-string def)) + (name (progn + (string-match " \\([^ ]+\\)>$" rep) + (match-string 1 rep)))) + (if (looking-at (format "(%s[ )]" name)) + (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-min)) + (forward-paragraph) + (insert + "[Missing arglist. Please make a bug report.]\n"))) + (goto-char (point-max)))) + (help-setup-xref (list #'describe-function function) + interactive-p)) (princ "not documented"))))) -;; We return 0 if we can't find a variable to return. (defun variable-at-point () + "Return the bound variable symbol found around point. +Return 0 if there is no such symbol." (condition-case () - (let ((stab (syntax-table))) - (unwind-protect - (save-excursion - (set-syntax-table emacs-lisp-mode-syntax-table) - (or (not (zerop (skip-syntax-backward "_w"))) - (eq (char-syntax (following-char)) ?w) - (eq (char-syntax (following-char)) ?_) - (forward-sexp -1)) - (skip-chars-forward "'") - (let ((obj (read (current-buffer)))) - (or (and (symbolp obj) (boundp obj) obj) - 0))) - (set-syntax-table stab))) + (with-syntax-table emacs-lisp-mode-syntax-table + (save-excursion + (or (not (zerop (skip-syntax-backward "_w"))) + (eq (char-syntax (following-char)) ?w) + (eq (char-syntax (following-char)) ?_) + (forward-sexp -1)) + (skip-chars-forward "'") + (let ((obj (read (current-buffer)))) + (or (and (symbolp obj) (boundp obj) obj) + 0)))) (error 0))) -(defun describe-variable (variable) +(defun help-xref-on-pp (from to) + "Add xrefs for symbols in `pp's output between FROM and TO." + (let ((ost (syntax-table))) + (unwind-protect + (save-excursion + (save-restriction + (set-syntax-table emacs-lisp-mode-syntax-table) + (narrow-to-region from to) + (goto-char (point-min)) + (while (not (eobp)) + (cond + ((looking-at "\"") (forward-sexp 1)) + ((looking-at "#<") (search-forward ">" nil 'move)) + ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)") + (let* ((sym (intern-soft (match-string 1))) + (fn (cond ((fboundp sym) #'describe-function) + ((or (memq sym '(t nil)) + (keywordp sym)) + nil) + ((and sym (boundp sym)) + #'describe-variable)))) + (when fn (help-xref-button 1 fn sym))) + (goto-char (match-end 1))) + (t (forward-char 1)))))) + (set-syntax-table ost)))) + +(defun describe-variable (variable &optional buffer) "Display the full documentation of VARIABLE (a symbol). -Returns the documentation as a string, also." - (interactive +Returns the documentation as a string, also. +If VARIABLE has a buffer-local value in BUFFER (default to the current buffer), +it is displayed along with the global value." + (interactive (let ((v (variable-at-point)) (enable-recursive-minibuffers t) val) (setq val (completing-read (if (symbolp v) - (format "Describe variable (default %s): " v) + (format + "Describe variable (default %s): " v) "Describe variable: ") obarray 'boundp t nil nil (if (symbolp v) (symbol-name v)))) (list (if (equal val "") v (intern val))))) - (if (symbolp variable) - (let (valvoid) + (unless (bufferp buffer) (setq buffer (current-buffer))) + (if (not (symbolp variable)) + (message "You did not specify a variable") + (let (valvoid) + (with-current-buffer buffer (with-output-to-temp-buffer "*Help*" (prin1 variable) (if (not (boundp variable)) (progn (princ " is void") - (terpri) (setq valvoid t)) - (princ "'s value is ") - (terpri) - (pp (symbol-value variable)) - (terpri)) + (let ((val (symbol-value variable))) + (with-current-buffer standard-output + (princ "'s value is ") + (terpri) + (let ((from (point))) + (pp val) + (help-xref-on-pp from (point)))))) + (terpri) (if (local-variable-p variable) (progn (princ (format "Local in buffer %s; " (buffer-name))) (if (not (default-boundp variable)) (princ "globally void") - (princ "global value is ") - (terpri) - (pp (default-value variable))) + (let ((val (default-value variable))) + (with-current-buffer standard-output + (princ "global value is ") + (terpri) + ;; Fixme: pp can take an age if you happen to + ;; ask for a very large expression. We should + ;; probably print it raw once and check it's a + ;; sensible size before prettyprinting. -- fx + (let ((from (point))) + (pp val) + (help-xref-on-pp from (point)))))) (terpri))) (terpri) - (save-current-buffer - (set-buffer standard-output) + (with-current-buffer standard-output (if (> (count-lines (point-min) (point-max)) 10) (progn + ;; Note that setting the syntax table like below + ;; makes forward-sexp move over a `'s' at the end + ;; of a symbol. + (set-syntax-table emacs-lisp-mode-syntax-table) (goto-char (point-min)) (if valvoid (forward-line 1) (forward-sexp 1) (delete-region (point) (progn (end-of-line) (point))) - (insert "'s value is shown below.\n\n") + (insert " value is shown below.\n\n") (save-excursion (insert "\n\nValue:")))))) (princ "Documentation:") (terpri) (let ((doc (documentation-property variable 'variable-documentation))) (princ (or doc "not documented as a variable."))) - (help-setup-xref (list #'describe-variable variable) (interactive-p)) - + (help-setup-xref (list #'describe-variable variable (current-buffer)) + (interactive-p)) + ;; Make a link to customize if this variable can be customized. - ;; Note, it is not reliable to test for a custom-type property + ;; 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 (user-variable-p variable) + (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) (princ (concat "You can " customize-label " this variable.")) (with-current-buffer "*Help*" (save-excursion - (re-search-backward + (re-search-backward (concat "\\(" customize-label "\\)") nil t) - (help-xref-button 1 #'(lambda (v) - (customize-variable v)) variable) - )))) + (help-xref-button 1 (lambda (v) + (if help-xref-stack + (pop help-xref-stack)) + (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 + ;; anything expects the current format.) + (let ((file-name (symbol-file variable))) + (when file-name + (princ "\n\nDefined in `") + (princ file-name) + (princ "'.") + (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 "mouse-2, RET: find variable's definition"))))) (print-help-return-message) (save-excursion (set-buffer standard-output) ;; Return the text we displayed. - (buffer-string)))) - (message "You did not specify a variable"))) + (buffer-string))))))) (defun describe-bindings (&optional prefix buffer) "Show a list of all defined keys, and their definitions. @@ -763,7 +941,7 @@ to display (default, the current buffer)." (interactive-p)))) (defun where-is (definition &optional insert) - "Print message listing key sequences that invoke specified command. + "Print message listing key sequences that invoke the command DEFINITION. Argument is a command definition, usually a symbol with a function definition. If INSERT (the prefix arg) is non-nil, insert the message in the buffer." (interactive @@ -773,7 +951,7 @@ If INSERT (the prefix arg) is non-nil, insert the message in the buffer." (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))) @@ -797,15 +975,19 @@ Optional second arg NOSUFFIX non-nil means don't add suffixes `.elc' or `.el' to the specified name LIBRARY. If the optional third arg PATH is specified, that list of directories -is used instead of `load-path'." +is used instead of `load-path'. + +When called from a program, the file name is normaly returned as a +string. When run interactively, the argument INTERACTIVE-CALL is t, +and the file name is displayed in the echo area." (interactive (list (read-string "Locate library: ") nil nil t)) (let (result) (catch 'answer - (mapcar + (mapc (lambda (dir) - (mapcar + (mapc (lambda (suf) (let ((try (expand-file-name (concat library suf) dir))) (and (file-readable-p try) @@ -849,8 +1031,7 @@ is used instead of `load-path'." (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) @@ -862,22 +1043,31 @@ Must be previously-defined." :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\\)\\|" + "\\(face\\)\\|" + "\\(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 - "\\ (move-to-column col) 0) - (looking-at "\\(\\sw\\|\\s_\\)+$")) - ;; + (and (eolp) (forward-line)) + (end-of-line) + (skip-chars-backward "^\t\n") + (if (and (>= (current-column) col) + (looking-at "\\(\\sw\\|-\\)+$")) (let ((sym (intern-soft (match-string 0)))) (if (fboundp sym) - (help-xref-button - 0 #'describe-function sym)))) - t) - (zerop (forward-line)) - (move-to-column 0))))))) + (help-xref-button + 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. - (when help-xref-stack + (when (and help-xref-following help-xref-stack) (goto-char (point-max)) (save-excursion (insert "\n\n" help-back-label)) @@ -995,24 +1256,44 @@ that." 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'." - (add-text-properties (match-beginning match-number) - (match-end match-number) - (list 'mouse-face 'highlight - 'help-xref (cons function - (if (listp data) - data - (list data))))) - (if help-highlight-p - (put-text-property (match-beginning match-number) - (match-end match-number) - 'face help-highlight-face))) +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) + (match-end match-number) + (list 'mouse-face 'highlight + 'help-xref (cons function + (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) + 'face help-highlight-face)))) + +(defun help-insert-xref-button (string function data &optional help-echo) + "Insert STRING and make a hyperlink from cross-reference text on it. + +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'. +If optional arg HELP-ECHO is supplied, it is used as a help string." + (let ((pos (point))) + (insert string) + (goto-char pos) + (search-forward string) + (help-xref-button 0 function data help-echo))) + ;; Additional functions for (re-)creating types of help buffers. @@ -1021,14 +1302,24 @@ See `help-make-xrefs'." 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)) - (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))) + (facedoc (when (facep symbol) (describe-face 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 (or fdoc facedoc) + (with-current-buffer "*Help*" + (goto-char (point-min)) + (let ((inhibit-read-only t)) + (when fdoc + (insert fdoc "\n\n")) + (when facedoc + (insert (make-string 30 ?-) "\n\n" (symbol-name symbol) + " is also a " "face." "\n\n" facedoc "\n\n")) + (insert (make-string 30 ?-) "\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." @@ -1048,21 +1339,24 @@ help buffer." (help-follow pos)))) (defun help-xref-go-back (buffer) - "Go back to the previous help buffer text using info on `help-xref-stack'." - (interactive) + "From BUFFER, go back to previous help buffer text using `help-xref-stack'." (let (item position method args) (with-current-buffer buffer (when help-xref-stack (setq help-xref-stack (cdr help-xref-stack)) ; due to help-follow - (setq item (car help-xref-stack) + (setq item (pop help-xref-stack) position (car item) method (cadr item) - args (cddr item)) - (setq help-xref-stack (cdr help-xref-stack)))) + args (cddr item)))) (apply method args) - (goto-char position))) + ;; We assume that the buffer we just recreated has the saved name, + ;; which might not always be true. + (when (get-buffer (cdr position)) + (with-current-buffer (cdr position) + (goto-char (car position)))))) (defun help-go-back () + "Invoke the [back] button (if any) in the Help mode buffer." (interactive) (help-follow (1- (point-max)))) @@ -1071,18 +1365,33 @@ help 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 (cons pos (buffer-name)) + help-xref-stack-item) + help-xref-stack)) + (setq help-xref-stack-item nil) ;; There is a reference at point. Follow it. - (apply method args)))) + (let ((help-xref-following t)) + (apply method args))))) ;; For tabbing through buffer. (defun help-next-ref () @@ -1117,4 +1426,148 @@ For the cross-reference format, see `help-make-xrefs'." (t ; be circular (goto-char (point-max))))))) + +;;; Automatic resizing of temporary buffers. + +(defcustom temp-buffer-max-height (lambda (buffer) (/ (- (frame-height) 2) 2)) + "*Maximum height of a window displaying a temporary buffer. +This is the maximum height (in text lines) which `resize-temp-buffer-window' +will give to a window displaying a temporary buffer. +It can also be a function which will be called with the object corresponding +to the buffer to be displayed as argument and should return an integer +positive number." + :type '(choice integer function) + :group 'help + :version "20.4") + +(define-minor-mode temp-buffer-resize-mode + "Toggle the mode which makes windows smaller for temporary buffers. +With prefix argument ARG, turn the resizing of windows displaying temporary +buffers on if ARG is positive or off otherwise. +This makes the window the right height for its contents, but never +more than `temp-buffer-max-height' nor less than `window-min-height'. +This applies to `help', `apropos' and `completion' buffers, and some others." + nil nil nil :global t :group 'help + (if temp-buffer-resize-mode + ;; `help-mode-maybe' may add a `back' button and thus increase the + ;; text size, so `resize-temp-buffer-window' must be run *after* it. + (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append) + (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window))) + +(defun resize-temp-buffer-window () + "Resize the current window to fit its contents. +Will not make it higher than `temp-buffer-max-height' nor smaller than +`window-min-height'. Do nothing if it is the only window on its frame, if it +is not as wide as the frame or if some of the window's contents are scrolled +out of view." + (unless (or (one-window-p 'nomini) + (not (pos-visible-in-window-p (point-min))) + (/= (frame-width) (window-width))) + (fit-window-to-buffer + (selected-window) + (if (functionp temp-buffer-max-height) + (funcall temp-buffer-max-height (current-buffer)) + temp-buffer-max-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'. + +;; This will find any missing items: +;; (let (l) +;; (mapatoms (lambda (x) +;; (if (and (fboundp x) +;; (subrp (symbol-function x)) +;; (not (numberp (cdr (subr-arity (symbol-function x))))) +;; (not (assq x help-manyarg-func-alist))) +;; (push x l)))) +;; l) +(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)") + (call-process-region + . "(call-process-region START END PROGRAM &optional DELETE 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-and-inherit . "(insert-and-inherit &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 BODY ...)") + (ml-if . "(ml-if COND THEN ELSE...)") + (ml-provide-prefix-argument . "(ml-provide-prefix-argument ARG1 ARG2)") + (ml-prefix-argument-loop . "(ml-prefix-argument-loop ...)") + (with-output-to-temp-buffer + . "(with-output-to-temp-buffer BUFFNAME BODY ...)") + (save-window-excursion . "(save-window-excursion BODY ...)") + (find-operation-coding-system + . "(find-operation-coding-system OPERATION ARGUMENTS ...)") + (insert-before-markers-and-inherit + . "(insert-before-markers-and-inherit &rest ARGS)")))) + +;; Provide this for the sake of define-minor-mode which generates +;; defcustoms which require 'help'. + +(provide 'help) + ;;; help.el ends here