(help-xref-on-pp): New function.

[gnu-emacs] / lisp / help.el

diff --git a/lisp/help.el b/lisp/help.el
index b0ca05a747447672f1d8e33fcf97ec574643ffd8..fed3dd7f691d29e8f3a97e73ce04ba3862a8a2d4 100644 (file)
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -1,6 +1,6 @@
 ;;; help.el --- help commands for Emacs
 
 ;;; 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
 
 ;; Maintainer: FSF
 ;; Keywords: help, internal


@@ -25,13 +25,14 @@
 ;;; Commentary:
 
 ;; This code implements GNU Emacs' on-line help system, the one invoked by
 ;;; 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))
 
 ;;; 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.")
 
 (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)
 
 (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)
 (define-key help-map "s" 'describe-syntax)
 
 (define-key help-map "t" 'help-with-tutorial)


@@ -101,26 +104,6 @@
 ;; Documentation only, since we use minor-mode-overriding-map-alist.
 (define-key help-mode-map "\r" 'help-follow)
 
 ;; 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'.
 (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'.


@@ -135,6 +118,11 @@ The format is (FUNCTION ARGS...).")
 
 (setq-default help-xref-stack nil help-xref-stack-item nil)
 
 
 (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'.
 (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'.


@@ -216,6 +204,19 @@ With arg, you are asked to choose which language."
       (goto-char (point-min))
       (set-buffer-modified-p nil))))
 
       (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."
 (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."


@@ -236,7 +237,8 @@ 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.
            (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))
            (key-desc (key-description key)))
        (if (or (null defn) (integerp defn))
            (princ (format "%s is undefined" key-desc))


@@ -317,7 +319,7 @@ If FUNCTION is nil, applies `message' to it, thus printing it."
          (progn
            (set-buffer (window-buffer window))
            (goto-char position)))
          (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*"
        (if (or (null defn) (integerp defn))
            (message "%s is undefined" (key-description key))
          (with-output-to-temp-buffer "*Help*"


@@ -438,7 +440,13 @@ With numeric argument display information on correspondingly older changes."
 (defun view-emacs-FAQ ()
   "Display the Emacs Frequently Asked Questions (FAQ) file."
   (interactive)
 (defun view-emacs-FAQ ()
   "Display the Emacs Frequently Asked Questions (FAQ) file."
   (interactive)

-  (find-file-read-only (expand-file-name "FAQ" data-directory)))
+;;;  (find-file-read-only (expand-file-name "FAQ" data-directory))
+  (info "(emacs-faq)"))
+
+(defun view-emacs-problems ()
+  "Display info on known problems with Emacs and possible workarounds."
+  (interactive)
+  (view-file (expand-file-name "PROBLEMS" data-directory)))

 
 (defun view-lossage ()
   "Display last 100 input keystrokes."
 
 (defun view-lossage ()
   "Display last 100 input keystrokes."


@@ -632,6 +640,18 @@ It can also be nil, if the definition is not associated with any file."
                         (if (eq (nth 4 def) 'keymap) "keymap"
                           (if (nth 4 def) "Lisp macro" "Lisp 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)
                (t "")))
     (when (and parens (not (equal string "")))
       (setq need-close t)


@@ -641,7 +661,8 @@ It can also be nil, if the definition is not associated with any file."
       (save-excursion
        (save-match-data
          (if (re-search-backward "alias for `\\([^`']+\\)'" nil t)
       (save-excursion
        (save-match-data
          (if (re-search-backward "alias for `\\([^`']+\\)'" nil t)

-             (help-xref-button 1 #'describe-function def)))))
+             (help-xref-button 1 #'describe-function def
+                               "mouse-2, RET: describe this function")))))

     (or file-name
        (setq file-name (symbol-file function)))
     (if file-name
     (or file-name
        (setq file-name (symbol-file function)))
     (if file-name


@@ -660,7 +681,8 @@ It can also be nil, if the definition is not associated with any file."
                                             (find-function-noselect arg)))
                                        (pop-to-buffer (car location))
                                        (goto-char (cdr location))))
                                             (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)
     (if need-close (princ ")"))
     (princ ".")
     (terpri)


@@ -673,21 +695,41 @@ It can also be nil, if the definition is not associated with any file."
                          (car (append def nil)))
                         ((eq (car-safe def) 'lambda)
                          (nth 1 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))))
                         (t t))))

-      (if (listp arglist)
-         (progn
-           (princ (cons (if (symbolp function) function "anonymous")
-                        (mapcar (lambda (arg)
-                                  (if (memq arg '(&optional &rest))
-                                      arg
-                                    (intern (upcase (symbol-name arg)))))
-                                arglist)))
-           (terpri))))
+      (cond ((listp arglist)
+            (princ (cons (if (symbolp function) function "anonymous")
+                         (mapcar (lambda (arg)
+                                   (if (memq arg '(&optional &rest))
+                                       arg
+                                     (intern (upcase (symbol-name arg)))))
+                                 arglist)))
+            (terpri))
+           ((stringp arglist)
+            (princ arglist)
+            (terpri))))

     (let ((doc (documentation function)))
       (if doc
          (progn (terpri)
                 (princ doc)
     (let ((doc (documentation function)))
       (if doc
          (progn (terpri)
                 (princ doc)

-                (help-setup-xref (list #'describe-function function) interactive-p))
+                (with-current-buffer standard-output
+                  (beginning-of-line)
+                  ;; Builtins get the calling sequence at the end of
+                  ;; the doc string.  Move it to the same place as
+                  ;; for other functions.
+                  (when (looking-at (format "(%S[ )]" function))
+                    (let ((start (point-marker)))
+                      (goto-char (point-min))
+                      (forward-paragraph)
+                      (insert-buffer-substring (current-buffer) start)
+                      (insert ?\n)
+                      (delete-region (1- start) (point-max))
+                      (goto-char (point-max)))))
+                (help-setup-xref (list #'describe-function function)
+                                 interactive-p))

        (princ "not documented")))))
 
 (defun variable-at-point ()
        (princ "not documented")))))
 
 (defun variable-at-point ()


@@ -709,6 +751,29 @@ Return 0 if there is no such symbol."
          (set-syntax-table stab)))
     (error 0)))
 
          (set-syntax-table stab)))
     (error 0)))
 

+(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
+                            (buffer-substring (match-beginning 1) (match-end 1))))
+                      (fn (cond ((fboundp sym) #'describe-function)
+                                ((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)
   "Display the full documentation of VARIABLE (a symbol).
 Returns the documentation as a string, also."
 (defun describe-variable (variable)
   "Display the full documentation of VARIABLE (a symbol).
 Returns the documentation as a string, also."


@@ -730,26 +795,34 @@ Returns the documentation as a string, also."
          (if (not (boundp variable))
              (progn
                (princ " is void")
          (if (not (boundp variable))
              (progn
                (princ " is void")

-               (terpri)

                (setq valvoid t))
                (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")
          (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)
+                     (let ((from (point)))
+                       (pp val)
+                       (help-xref-on-pp from (point))))))

                (terpri)))
          (terpri)
          (save-current-buffer
            (set-buffer standard-output)
            (if (> (count-lines (point-min) (point-max)) 10)
                (progn
                (terpri)))
          (terpri)
          (save-current-buffer
            (set-buffer standard-output)
            (if (> (count-lines (point-min) (point-max)) 10)
                (progn

+                 (set-syntax-table emacs-lisp-mode-syntax-table)

                  (goto-char (point-min))
                  (if valvoid
                      (forward-line 1)
                  (goto-char (point-min))
                  (if valvoid
                      (forward-line 1)


@@ -768,9 +841,9 @@ Returns the documentation as a string, also."
          ;; 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.
          ;; Note, it is not reliable to test only for a custom-type property
          ;; because those are only present after the var's definition
          ;; has been loaded.

-         (if (or (user-variable-p variable)
-                 (get variable 'custom-loads)
-                 (get variable 'custom-type))
+         (if (or (get variable 'custom-type) ; after defcustom
+                 (get variable 'custom-loads) ; from loaddefs.el
+                 (get variable 'standard-value)) ; from cus-start.el

              (let ((customize-label "customize"))
                (terpri)
                (terpri)
              (let ((customize-label "customize"))
                (terpri)
                (terpri)


@@ -780,7 +853,9 @@ Returns the documentation as a string, also."
                    (re-search-backward 
                     (concat "\\(" customize-label "\\)") nil t)
                    (help-xref-button 1 #'(lambda (v)
                    (re-search-backward 
                     (concat "\\(" customize-label "\\)") nil t)
                    (help-xref-button 1 #'(lambda (v)

-                                           (customize-variable v)) variable)
+                                           (customize-variable v))
+                                     variable
+                                     "mouse-2, RET: customize variable")

                    ))))
          ;; Make a hyperlink to the library if appropriate.  (Don't
          ;; change the format of the buffer's initial line in case
                    ))))
          ;; Make a hyperlink to the library if appropriate.  (Don't
          ;; change the format of the buffer's initial line in case


@@ -793,12 +868,13 @@ Returns the documentation as a string, also."
              (with-current-buffer "*Help*"
                (save-excursion
                  (re-search-backward "`\\([^`']+\\)'" nil t)
              (with-current-buffer "*Help*"
                (save-excursion
                  (re-search-backward "`\\([^`']+\\)'" nil t)

-                 (help-xref-button 1 (lambda (arg)
-                                       (let ((location
-                                              (find-variable-noselect arg)))
-                                         (pop-to-buffer (car location))
-                                         (goto-char (cdr location))))
-                                   variable)))))
+                 (help-xref-button
+                  1 (lambda (arg)
+                      (let ((location
+                             (find-variable-noselect arg)))
+                        (pop-to-buffer (car location))
+                        (goto-char (cdr location))))
+                  variable "mouse-2, RET: find variable's definition")))))

 
          (print-help-return-message)
          (save-excursion
 
          (print-help-return-message)
          (save-excursion


@@ -834,7 +910,7 @@ 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: ")
      (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)))
      (list (if (equal val "")
               fn (intern val))
           current-prefix-arg)))


@@ -914,8 +990,7 @@ and the file name is displayed in the echo area."
 (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
 (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)
  :group 'help
  :version "20.3"
  :type 'boolean)


@@ -927,22 +1002,22 @@ Must be previously-defined."
   :version "20.3"
   :type 'face)
 
   :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.")
 
   "Label to use by `help-make-xrefs' for the go-back reference.")
 

-(defvar help-xref-symbol-regexp
-  (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
-          "\\(function\\|command\\)\\|"
-          "\\(symbol\\)\\)\\s-+\\)?"
-          ;; Note starting with word-syntax character:
-          "`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'")
+(defconst help-xref-symbol-regexp
+  (purecopy (concat "\\(\\<\\(\\(variable\\|option\\)\\|"
+                   "\\(function\\|command\\)\\|"
+                   "\\(symbol\\)\\)\\s-+\\)?"
+                   ;; Note starting with word-syntax character:
+                   "`\\(\\sw\\(\\sw\\|\\s_\\)+\\)'"))

   "Regexp matching doc string references to symbols.
 
 The words preceding the quoted symbol can be used in doc strings to
 distinguish references to variables, functions and symbols.")
 
   "Regexp matching doc string references to symbols.
 
 The words preceding the quoted symbol can be used in doc strings to
 distinguish references to variables, functions and symbols.")
 

-(defvar help-xref-info-regexp
-  "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'"
+(defconst help-xref-info-regexp
+  (purecopy "\\<[Ii]nfo[ \t\n]+node[ \t\n]+`\\([^']+\\)'")

   "Regexp matching doc string references to an Info node.")
 
 (defun help-setup-xref (item interactive-p)
   "Regexp matching doc string references to an Info node.")
 
 (defun help-setup-xref (item interactive-p)


@@ -991,7 +1066,8 @@ that."
                    (save-match-data
                      (unless (string-match "^([^)]+)" data)
                        (setq data (concat "(emacs)" data))))
                    (save-match-data
                      (unless (string-match "^([^)]+)" data)
                        (setq data (concat "(emacs)" data))))

-                   (help-xref-button 1 #'info data))))
+                   (help-xref-button 1 #'info data
+                                     "mouse-2, RET: read this Info node"))))

               ;; Quoted symbols
               (save-excursion
                 (while (re-search-forward help-xref-symbol-regexp nil t)
               ;; Quoted symbols
               (save-excursion
                 (while (re-search-forward help-xref-symbol-regexp nil t)


@@ -1002,19 +1078,29 @@ that."
                          ((match-string 3) ; `variable' &c
                           (and (boundp sym) ; `variable' doesn't ensure
                                         ; it's actually bound
                          ((match-string 3) ; `variable' &c
                           (and (boundp sym) ; `variable' doesn't ensure
                                         ; it's actually bound

-                               (help-xref-button 6 #'describe-variable sym)))
+                               (help-xref-button
+                               6 #'describe-variable sym
+                               "mouse-2, RET: describe this variable")))

                          ((match-string 4) ; `function' &c
                           (and (fboundp sym) ; similarly
                          ((match-string 4) ; `function' &c
                           (and (fboundp sym) ; similarly

-                               (help-xref-button 6 #'describe-function sym)))
+                               (help-xref-button
+                               6 #'describe-function sym
+                               "mouse-2, RET: describe this function")))

                          ((match-string 5)) ; nothing for symbol
                          ((and (boundp sym) (fboundp sym))
                           ;; We can't intuit whether to use the
                           ;; variable or function doc -- supply both.
                          ((match-string 5)) ; nothing for symbol
                          ((and (boundp sym) (fboundp sym))
                           ;; We can't intuit whether to use the
                           ;; variable or function doc -- supply both.

-                          (help-xref-button 6 #'help-xref-interned sym))
+                          (help-xref-button
+                          6 #'help-xref-interned sym
+                          "mouse-2, RET: describe this symbol"))

                          ((boundp sym)
                          ((boundp sym)

-                          (help-xref-button 6 #'describe-variable sym))
-                         ((fboundp sym)
-                          (help-xref-button 6 #'describe-function sym)))))))
+                         (help-xref-button
+                          6 #'describe-variable sym
+                          "mouse-2, RET: describe this variable"))
+                        ((fboundp sym)
+                         (help-xref-button
+                          6 #'describe-function sym
+                          "mouse-2, RET: describe this function")))))))

               ;; An obvious case of a key substitution:
               (save-excursion              
                 (while (re-search-forward
               ;; An obvious case of a key substitution:
               (save-excursion              
                 (while (re-search-forward


@@ -1023,7 +1109,9 @@ that."
                         "\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t)
                   (let ((sym (intern-soft (match-string 1))))
                     (if (fboundp sym)
                         "\\<M-x\\s-+\\(\\sw\\(\\sw\\|-\\)+\\)" nil t)
                   (let ((sym (intern-soft (match-string 1))))
                     (if (fboundp sym)

-                        (help-xref-button 1 #'describe-function sym)))))
+                        (help-xref-button
+                        1 #'describe-function sym
+                        "mouse-2, RET: describe this command")))))

               ;; Look for commands in whole keymap substitutions:
               (save-excursion
                ;; Make sure to find the first keymap.
               ;; Look for commands in whole keymap substitutions:
               (save-excursion
                ;; Make sure to find the first keymap.


@@ -1036,7 +1124,7 @@ that."
                     (while
                         ;; Ignore single blank lines in table, but not
                         ;; double ones, which should terminate it.
                     (while
                         ;; Ignore single blank lines in table, but not
                         ;; double ones, which should terminate it.

-                        (and (not (looking-at "\n\n"))
+                        (and (not (looking-at "\n\\s-*\n"))

                              (progn
                               (and (eolp) (forward-line))
                               (end-of-line)
                              (progn
                               (and (eolp) (forward-line))
                               (end-of-line)


@@ -1046,7 +1134,8 @@ that."
                                    (let ((sym (intern-soft (match-string 0))))
                                      (if (fboundp sym)
                                          (help-xref-button 
                                    (let ((sym (intern-soft (match-string 0))))
                                      (if (fboundp sym)
                                          (help-xref-button 

-                                          0 #'describe-function sym))))
+                                          0 #'describe-function sym
+                                         "mouse-2, RET: describe this function"))))

                               (zerop (forward-line)))))))))
           (set-syntax-table stab))
         ;; Make a back-reference in this buffer if appropriate.
                               (zerop (forward-line)))))))))
           (set-syntax-table stab))
         ;; Make a back-reference in this buffer if appropriate.


@@ -1066,13 +1155,14 @@ that."
                          map))))
       (set-buffer-modified-p old-modified))))
 
                          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.
   "Make a hyperlink for cross-reference text previously matched.
 
 MATCH-NUMBER is the subexpression of interest in the last matched
 regexp.  FUNCTION is a function to invoke when the button is
 activated, applied to DATA.  DATA may be a single value or a list.

-See `help-make-xrefs'."
+See `help-make-xrefs'.
+If optional arg HELP-ECHO is supplied, it is used as a help string."

   ;; Don't mung properties we've added specially in some instances.
   (unless (get-text-property (match-beginning match-number) 'help-xref)
     (add-text-properties (match-beginning match-number)
   ;; 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)


@@ -1082,6 +1172,10 @@ See `help-make-xrefs'."
                                                (if (listp data)
                                                    data
                                                  (list data)))))
                                                (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)
     (if help-highlight-p
        (put-text-property (match-beginning match-number)
                           (match-end match-number)


@@ -1094,15 +1188,17 @@ See `help-make-xrefs'."
 
 Both variable and function documentation are extracted into a single
 help buffer."
 
 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 before it.
-    (with-current-buffer "*Help*"
-      (goto-char (point-min))
-      (let ((inhibit-read-only t))
-       (insert fdoc "\n\n" (symbol-name symbol) " is also a variable.\n\n"))
-      (help-setup-xref (list #'help-xref-interned symbol) nil))))
+  (let ((fdoc (when (fboundp symbol) (describe-function symbol))))
+    (when (or (boundp symbol) (not fdoc))
+      (describe-variable symbol)
+      ;; We now have a help buffer on the variable.  Insert the function
+      ;; text before it.
+      (when fdoc
+       (with-current-buffer "*Help*"
+         (goto-char (point-min))
+         (let ((inhibit-read-only t))
+           (insert fdoc "\n\n" (symbol-name symbol) " is also a variable.\n\n"))
+         (help-setup-xref (list #'help-xref-interned symbol) nil))))))

 
 (defun help-xref-mode (buffer)
   "Do a `describe-mode' for the specified BUFFER."
 
 (defun help-xref-mode (buffer)
   "Do a `describe-mode' for the specified BUFFER."


@@ -1133,7 +1229,10 @@ help buffer."
              args (cddr item))
        (setq help-xref-stack (cdr help-xref-stack))))
     (apply method args)
              args (cddr item))
        (setq help-xref-stack (cdr help-xref-stack))))
     (apply method args)

-    (goto-char position)))
+    ;; We're not in the right buffer to do this, and we don't actually
+    ;; know which we should be in.
+    ;;(goto-char position)
+    ))

 
 (defun help-go-back ()
   "Invoke the [back] button (if any) in the Help mode buffer."
 
 (defun help-go-back ()
   "Invoke the [back] button (if any) in the Help mode buffer."


@@ -1145,16 +1244,29 @@ help buffer."
 
 For the cross-reference format, see `help-make-xrefs'."
   (interactive "d")
 
 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)))
          (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
     (when help-data

+      (setq help-xref-stack (cons (cons (point) help-xref-stack-item)
+                                 help-xref-stack))
+      (setq help-xref-stack-item nil)

       ;; There is a reference at point.  Follow it.
       (apply method args))))
 
       ;; There is a reference at point.  Follow it.
       (apply method args))))
 


@@ -1256,8 +1368,86 @@ out of view."
                          temp-buffer-max-height))
            (win-height (1- (window-height)))
            (min-height (1- window-min-height))
                          temp-buffer-max-height))
            (win-height (1- (window-height)))
            (min-height (1- window-min-height))

-           (text-height (window-buffer-height(selected-window)))
+           (text-height (count-screen-lines))

            (new-height (max (min text-height max-height) min-height)))
       (enlarge-window (- new-height win-height)))))
 
            (new-height (max (min text-height max-height) min-height)))
       (enlarge-window (- new-height win-height)))))
 

+;; `help-manyarg-func-alist' is defined primitively (in doc.c).
+;; New primitives with `MANY' or `UNEVALLED' arglists should be added
+;; to this alist.
+;; The parens and function name are redundant, but it's messy to add
+;; them in `documentation'.
+(defconst help-manyarg-func-alist
+  (purecopy
+   '((list . "(list &rest OBJECTS)")
+     (vector . "(vector &rest OBJECTS)")
+     (make-byte-code . "(make-byte-code &rest ELEMENTS)")
+     (call-process
+      . "(call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)")
+     (string . "(string &rest CHARACTERS)")
+     (+ . "(+ &rest NUMBERS-OR-MARKERS)")
+     (- . "(- &optional NUMBER-OR-MARKER &rest MORE-NUMBERS-OR-MARKERS)")
+     (* . "(* &rest NUMBERS-OR-MARKERS)")
+     (/ . "(/ DIVIDEND DIVISOR &rest DIVISORS)")
+     (max . "(max NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)")
+     (min . "(min NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)")
+     (logand . "(logand &rest INTS-OR-MARKERS)")
+     (logior . "(logior &rest INTS-OR-MARKERS)")
+     (logxor . "(logxor &rest INTS-OR-MARKERS)")
+     (encode-time
+      . "(encode-time SECOND MINUTE HOUR DAY MONTH YEAR &optional ZONE)")
+     (insert . "(insert &rest ARGS)")
+     (insert-before-markers . "(insert-before-markers &rest ARGS)")
+     (message . "(message STRING &rest ARGUMENTS)")
+     (message-box . "(message-box STRING &rest ARGUMENTS)")
+     (message-or-box . "(message-or-box STRING &rest ARGUMENTS)")
+     (propertize . "(propertize STRING &rest PROPERTIES)")
+     (format . "(format STRING &rest OBJECTS)")
+     (apply . "(apply FUNCTION &rest ARGUMENTS)")
+     (run-hooks . "(run-hooks &rest HOOKS)")
+     (run-hook-with-args . "(run-hook-with-args HOOK &rest ARGS)")
+     (run-hook-with-args-until-failure
+      . "(run-hook-with-args-until-failure HOOK &rest ARGS)")
+     (run-hook-with-args-until-success
+      . "(run-hook-with-args-until-success HOOK &rest ARGS)")
+     (funcall . "(funcall FUNCTION &rest ARGUMENTS)")
+     (append . "(append &rest SEQUENCES)")
+     (concat . "(concat &rest SEQUENCES)")
+     (vconcat . "(vconcat vconcat)")
+     (nconc . "(nconc &rest LISTS)")
+     (widget-apply . "(widget-apply WIDGET PROPERTY &rest ARGS)")
+     (make-hash-table . "(make-hash-table &rest KEYWORD-ARGS)")
+     (insert-string . "(insert-string &rest ARGS)")
+     (start-process . "(start-process NAME BUFFER PROGRAM &rest PROGRAM-ARGS)")
+     (setq-default . "(setq-default SYMBOL VALUE [SYMBOL VALUE...])")
+     (save-excursion . "(save-excursion &rest BODY)")
+     (save-current-buffer . "(save-current-buffer &rest BODY)")
+     (save-restriction . "(save-restriction &rest BODY)")
+     (or . "(or CONDITIONS ...)")
+     (and . "(and CONDITIONS ...)")
+     (if . "(if COND THEN ELSE...)")
+     (cond . "(cond CLAUSES...)")
+     (progn . "(progn BODY ...)")
+     (prog1 . "(prog1 FIRST BODY...)")
+     (prog2 . "(prog2 X Y BODY...)")
+     (setq . "(setq SYM VAL SYM VAL ...)")
+     (quote . "(quote ARG)")
+     (function . "(function ARG)")
+     (defun . "(defun NAME ARGLIST [DOCSTRING] BODY...)")
+     (defmacro . "(defmacro NAME ARGLIST [DOCSTRING] BODY...)")
+     (defvar . "(defvar SYMBOL [INITVALUE DOCSTRING])")
+     (defconst . "(defconst SYMBOL INITVALUE [DOCSTRING])")
+     (let* . "(let* VARLIST BODY...)")
+     (let . "(let VARLIST BODY...)")
+     (while . "(while TEST BODY...)")
+     (catch . "(catch TAG BODY...)")
+     (unwind-protect . "(unwind-protect BODYFORM UNWINDFORMS...)")
+     (condition-case . "(condition-case VAR BODYFORM HANDLERS...)")
+     (track-mouse . "(track-mouse BOFY ...)")
+     (ml-if . "(ml-if COND THEN ELSE...)")
+     (ml-provide-prefix-argument . "(ml-provide-prefix-argument ARG1 ARG2)")
+     (with-output-to-temp-buffer
+        . "(with-output-to-temp-buffer BUFFNAME BODY ...)")
+     (save-window-excursion . "(save-window-excursion BODY ...)"))))
+

 ;;; help.el ends here
 ;;; help.el ends here