root/trunk/lisp/emacs-lisp/checkdoc.el

;;; checkdoc.el --- check documentation strings for style requirements

;; Copyright (C) 1997, 1998, 2001, 2002, 2003, 2004,
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: Eric M. Ludlam <zappo@gnu.org>
;; Version: 0.6.2
;; Keywords: docs, maint, lisp

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:
;;
;;   The Emacs Lisp manual has a nice chapter on how to write
;; documentation strings.  Many stylistic suggestions are fairly
;; deterministic and easy to check for syntactically, but also easy
;; to forget.  The main checkdoc engine will perform the stylistic
;; checks needed to make sure these styles are remembered.
;;
;; There are two ways to use checkdoc:
;;   1) Periodically use `checkdoc' or `checkdoc-current-buffer'.
;;      `checkdoc' is a more interactive version of
;;      `checkdoc-current-buffer'
;;   2) Use `checkdoc-minor-mode' to automatically check your
;;      documentation whenever you evaluate Lisp code with C-M-x
;;      or [menu-bar emacs-lisp eval-buffer].  Additional key-bindings
;;      are also provided under C-c ? KEY
;;        (require 'checkdoc)
;;        (add-hook 'emacs-lisp-mode-hook
;;                   '(lambda () (checkdoc-minor-mode 1)))
;;
;; Using `checkdoc':
;;
;;   The commands `checkdoc' and `checkdoc-ispell' are the top-level
;; entry points to all of the different checks that are available.  It
;; breaks examination of your Lisp file into four sections (comments,
;; documentation, messages, and spacing) and indicates its current
;; state in a status buffer.
;;
;;   The Comments check examines your headers, footers, and
;; various tags (such as "Code:") to make sure that your code is ready
;; for easy integration into existing systems.
;;
;;   The Documentation check deals with documentation strings
;; and their elements that help make Emacs easier to use.
;;
;;   The Messages check ensures that the strings displayed in the
;; minibuffer by some commands (such as `error' and `y-or-n-p')
;; are consistent with the Emacs environment.
;;
;;   The Spacing check cleans up white-space at the end of lines.
;;
;;   The interface while working with documentation and messages is
;; slightly different when being run in the interactive mode.  The
;; interface offers several options, including the ability to skip to
;; the next error, or back up to previous errors.  Auto-fixing is
;; turned off at this stage, but you can use the `f' or `F' key to fix
;; a given error (if the fix is available.)
;;
;; Auto-fixing:
;;
;;   There are four classifications of style errors in terms of how
;; easy they are to fix.  They are simple, complex, really complex,
;; and impossible.  (Impossible really means that checkdoc does not
;; have a fixing routine yet.)  Typically white-space errors are
;; classified as simple, and are auto-fixed by default.  Typographic
;; changes are considered complex, and the user is asked if they want
;; the problem fixed before checkdoc makes the change.  These changes
;; can be done without asking if `checkdoc-autofix-flag' is properly
;; set.  Potentially redundant changes are considered really complex,
;; and the user is always asked before a change is inserted.  The
;; variable `checkdoc-autofix-flag' controls how these types of errors
;; are fixed.
;;
;; Spell checking text:
;;
;;   The variable `checkdoc-spellcheck-documentation-flag' can be set
;; to customize how spell checking is to be done.  Since spell
;; checking can be quite slow, you can optimize how best you want your
;; checking done.  The default is `defun', which spell checks each time
;; `checkdoc-defun' or `checkdoc-eval-defun' is used.  Setting to nil
;; prevents spell checking during normal usage.
;;   Setting this variable to nil does not mean you cannot take
;; advantage of the spell checking.  You can instead use the
;; interactive functions `checkdoc-ispell-*' to check the spelling of
;; your documentation.
;;   There is a list of Lisp-specific words which checkdoc will
;; install into Ispell on the fly, but only if Ispell is not already
;; running.  Use `ispell-kill-ispell' to make checkdoc restart it with
;; these words enabled.
;;
;; Checking parameters:
;;
;;   You might not always want a function to have its parameters listed
;; in order.  When this is the case, put the following comment just in
;; front of the documentation string: "; checkdoc-order: nil"  This
;; overrides the value of `checkdoc-arguments-in-order-flag'.
;;
;;   If you specifically wish to avoid mentioning a parameter of a
;; function in the doc string (such as a hidden parameter, or a
;; parameter which is very obvious like events), you can have checkdoc
;; skip looking for it by putting the following comment just in front
;; of the documentation string: "; checkdoc-params: (args go here)"
;;
;; Checking message strings:
;;
;;   The text that follows the `error' and `y-or-n-p' commands is
;; also checked.  The documentation for `error' clearly states some
;; simple style rules to follow which checkdoc will auto-fix for you.
;; `y-or-n-p' also states that it should end in a space.  I added that
;; it should end in "? " since that is almost always used.
;;
;; Adding your own checks:
;;
;;   You can experiment with adding your own checks by setting the
;; hooks `checkdoc-style-hooks' and `checkdoc-comment-style-hooks'.
;; Return a string which is the error you wish to report.  The cursor
;; position should be preserved.
;;
;; Error errors:
;;
;;   Checkdoc does not always flag errors correctly.  There are a
;; couple ways you can coax your file into passing all of checkdoc's
;; tests through buffer local variables.
;;
;;   The variable `checkdoc-verb-check-experimental-flag' can be used
;; to turn off the check for verb-voice in case you use words that are
;; not semantically verbs, but are still in the incomplete list.
;;
;;   The variable `checkdoc-symbol-words' can be a list of words that
;; happen to also be symbols.  This is not a problem for one-word
;; symbols, but if you use a hyphenated word that is also a symbol,
;; then you may need this.
;;
;;   The symbol `checkdoc-force-docstrings-flag' can be set to nil if
;; you have many undocumented functions you don't wish to document.
;;
;;   See the above section "Checking Parameters" for details about
;; parameter checking.
;;
;; Dependencies:
;;
;;   This file requires lisp-mnt (Lisp maintenance routines) for the
;;   comment checkers.
;;
;;   Requires custom for Emacs v20.

;;; TO DO:
;;   Hook into the byte compiler on a defun/defvar level to generate
;;     warnings in the byte-compiler's warning/error buffer.
;;   Better ways to override more typical `eval' functions.  Advice
;;     might be good but hard to turn on/off as a minor mode.
;;
;;; Maybe Do:
;;   Code sweep checks for "forbidden functions", proper use of hooks,
;;     proper keybindings, and other items from the manual that are
;;     not specifically docstring related.  Would this even be useful?

;;; Code:
(defvar checkdoc-version "0.6.1"
  "Release version of checkdoc you are currently running.")

;; From custom web page for compatibility between versions of custom:
(eval-and-compile
 (condition-case ()
     (require 'custom)
   (error nil))
 (if (and (featurep 'custom) (fboundp 'custom-declare-variable))
     nil ;; We've got what we needed
     ;; We have the old custom-library, hack around it!
     (defmacro defgroup (&rest args)
       nil)
     (defmacro custom-add-option (&rest args)
       nil)
     (defmacro defcustom (var value doc &rest args)
       `(defvar ,var ,value ,doc))))

(defvar compilation-error-regexp-alist)
(defvar compilation-mode-font-lock-keywords)

(defgroup checkdoc nil
  "Support for doc string checking in Emacs Lisp."
  :prefix "checkdoc"
  :group 'lisp
  :version "20.3")

(defcustom checkdoc-autofix-flag 'semiautomatic
  "Non-nil means attempt auto-fixing of doc strings.
If this value is the symbol `query', then the user is queried before
any change is made.  If the value is `automatic', then all changes are
made without asking unless the change is very-complex.  If the value
is `semiautomatic' or any other value, then simple fixes are made
without asking, and complex changes are made by asking the user first.
The value `never' is the same as nil, never ask or change anything."
  :group 'checkdoc
  :type '(choice (const automatic)
                 (const query)
                 (const never)
                 (other :tag "semiautomatic" semiautomatic)))

(defcustom checkdoc-bouncy-flag t
  "Non-nil means to \"bounce\" to auto-fix locations.
Setting this to nil will silently make fixes that require no user
interaction.  See `checkdoc-autofix-flag' for auto-fixing details."
  :group 'checkdoc
  :type 'boolean)

(defcustom checkdoc-force-docstrings-flag t
  "Non-nil means that all checkable definitions should have documentation.
Style guide dictates that interactive functions MUST have documentation,
and that it's good but not required practice to make non user visible items
have doc strings."
  :group 'checkdoc
  :type 'boolean)
(put 'checkdoc-force-docstrings-flag 'safe-local-variable 'booleanp)

(defcustom checkdoc-force-history-flag t
  "Non-nil means that files should have a History section or ChangeLog file.
This helps document the evolution of, and recent changes to, the package."
  :group 'checkdoc
  :type 'boolean)

(defcustom checkdoc-permit-comma-termination-flag nil
  "Non-nil means the first line of a docstring may end with a comma.
Ordinarily, a full sentence is required.  This may be misleading when
there is a substantial caveat to the one-line description -- the comma
should be used when the first part could stand alone as a sentence, but
it indicates that a modifying clause follows."
  :group 'checkdoc
  :type 'boolean)
(put 'checkdoc-permit-comma-termination-flag 'safe-local-variable 'booleanp)

(defcustom checkdoc-spellcheck-documentation-flag nil
  "Non-nil means run Ispell on text based on value.
This is automatically set to nil if Ispell does not exist on your
system.  Possible values are:

  nil         - Don't spell-check during basic style checks.
  defun       - Spell-check when style checking a single defun
  buffer      - Spell-check when style checking the whole buffer
  interactive - Spell-check during any interactive check.
  t           - Always spell-check"
  :group 'checkdoc
  :type '(choice (const nil)
                 (const defun)
                 (const buffer)
                 (const interactive)
                 (const t)))

(defvar checkdoc-ispell-lisp-words
  '("alist" "emacs" "etags" "keymap" "paren" "regexp" "sexp" "xemacs")
  "List of words that are correct when spell-checking Lisp documentation.")

(defcustom checkdoc-max-keyref-before-warn 10
  "The number of \\ [command-to-keystroke] tokens allowed in a doc string.
Any more than this and a warning is generated suggesting that the construct
\\ {keymap} be used instead."
  :group 'checkdoc
  :type 'integer)

(defcustom checkdoc-arguments-in-order-flag t
  "Non-nil means warn if arguments appear out of order.
Setting this to nil will mean only checking that all the arguments
appear in the proper form in the documentation, not that they are in
the same order as they appear in the argument list.  No mention is
made in the style guide relating to order."
  :group 'checkdoc
  :type 'boolean)

(defvar checkdoc-style-hooks nil
  "Hooks called after the standard style check is completed.
All hooks must return nil or a string representing the error found.
Useful for adding new user implemented commands.

Each hook is called with two parameters, (DEFUNINFO ENDPOINT).
DEFUNINFO is the return value of `checkdoc-defun-info'.  ENDPOINT is the
location of end of the documentation string.")

(defvar checkdoc-comment-style-hooks nil
  "Hooks called after the standard comment style check is completed.
Must return nil if no errors are found, or a string describing the
problem discovered.  This is useful for adding additional checks.")

(defvar checkdoc-diagnostic-buffer "*Style Warnings*"
  "Name of warning message buffer.")

(defvar checkdoc-defun-regexp
  "^(def\\(un\\|var\\|custom\\|macro\\|const\\|subst\\|advice\\)\
\\s-+\\(\\(\\sw\\|\\s_\\)+\\)[ \t\n]+"
  "Regular expression used to identify a defun.
A search leaves the cursor in front of the parameter list.")

(defcustom checkdoc-verb-check-experimental-flag t
  "Non-nil means to attempt to check the voice of the doc string.
This check keys off some words which are commonly misused.  See the
variable `checkdoc-common-verbs-wrong-voice' if you wish to add your own."
  :group 'checkdoc
  :type 'boolean)

(defvar checkdoc-generate-compile-warnings-flag nil
  "Non-nil means generate warnings in a buffer for browsing.
Do not set this by hand, use a function like `checkdoc-current-buffer'
with a universal argument.")

(defcustom checkdoc-symbol-words nil
  "A list of symbols which also happen to make good words.
These symbol-words are ignored when unquoted symbols are searched for.
This should be set in an Emacs Lisp file's local variables."
  :group 'checkdoc
  :type '(repeat (symbol :tag "Word")))

(defvar checkdoc-proper-noun-list
  '("ispell" "xemacs" "emacs" "lisp")
  "List of words (not capitalized) which should be capitalized.")

(defvar checkdoc-proper-noun-regexp
  (let ((expr "\\_<\\(")
        (l checkdoc-proper-noun-list))
    (while l
      (setq expr (concat expr (car l) (if (cdr l) "\\|" ""))
            l (cdr l)))
    (concat expr "\\)\\_>"))
  "Regular expression derived from `checkdoc-proper-noun-regexp'.")

(defvar checkdoc-common-verbs-regexp nil
  "Regular expression derived from `checkdoc-common-verbs-regexp'.")

(defvar checkdoc-common-verbs-wrong-voice
  '(("adds" . "add")
    ("allows" . "allow")
    ("appends" . "append")
    ("applies" . "apply")
    ("arranges" . "arrange")
    ("brings" . "bring")
    ("calls" . "call")
    ("catches" . "catch")
    ("changes" . "change")
    ("checks" . "check")
    ("contains" . "contain")
    ("converts" . "convert")
    ("creates" . "create")
    ("destroys" . "destroy")
    ("disables" . "disable")
    ("executes" . "execute")
    ("evals" . "evaluate")
    ("evaluates" . "evaluate")
    ("finds" . "find")
    ("forces" . "force")
    ("gathers" . "gather")
    ("generates" . "generate")
    ("goes" . "go")
    ("guesses" . "guess")
    ("highlights" . "highlight")
    ("holds" . "hold")
    ("ignores" . "ignore")
    ("indents" . "indent")
    ("initializes" . "initialize")
    ("inserts" . "insert")
    ("installs" . "install")
    ("investigates" . "investigate")
    ("keeps" . "keep")
    ("kills" . "kill")
    ("leaves" . "leave")
    ("lets" . "let")
    ("loads" . "load")
    ("looks" . "look")
    ("makes" . "make")
    ("marks" . "mark")
    ("matches" . "match")
    ("moves" . "move")
    ("notifies" . "notify")
    ("offers" . "offer")
    ("parses" . "parse")
    ("performs" . "perform")
    ("prepares" . "prepare")
    ("prepends" . "prepend")
    ("reads" . "read")
    ("raises" . "raise")
    ("removes" . "remove")
    ("replaces" . "replace")
    ("resets" . "reset")
    ("restores" . "restore")
    ("returns" . "return")
    ("runs" . "run")
    ("saves" . "save")
    ("says" . "say")
    ("searches" . "search")
    ("selects" . "select")
    ("sets" . "set")
    ("sex" . "s*x")
    ("shows" . "show")
    ("signifies" . "signify")
    ("sorts" . "sort")
    ("starts" . "start")
    ("stores" . "store")
    ("switches" . "switch")
    ("tells" . "tell")
    ("tests" . "test")
    ("toggles" . "toggle")
    ("tries" . "try")
    ("turns" . "turn")
    ("undoes" . "undo")
    ("unloads" . "unload")
    ("unmarks" . "unmark")
    ("updates" . "update")
    ("uses" . "use")
    ("yanks" . "yank")
    )
  "Alist of common words in the wrong voice and what should be used instead.
Set `checkdoc-verb-check-experimental-flag' to nil to avoid this costly
and experimental check.  Do not modify this list without setting
the value of `checkdoc-common-verbs-regexp' to nil which cause it to
be re-created.")

(defvar checkdoc-syntax-table nil
  "Syntax table used by checkdoc in document strings.")

(if checkdoc-syntax-table
    nil
  (setq checkdoc-syntax-table (copy-syntax-table emacs-lisp-mode-syntax-table))
  ;; When dealing with syntax in doc strings, make sure that - are encompassed
  ;; in words so we can use cheap \\> to get the end of a symbol, not the
  ;; end of a word in a conglomerate.
  (modify-syntax-entry ?- "w" checkdoc-syntax-table)
  )


;;; Compatibility
;;
(defalias 'checkdoc-make-overlay
  (if (featurep 'xemacs) 'make-extent 'make-overlay))
(defalias 'checkdoc-overlay-put
  (if (featurep 'xemacs) 'set-extent-property 'overlay-put))
(defalias 'checkdoc-delete-overlay
  (if (featurep 'xemacs) 'delete-extent 'delete-overlay))
(defalias 'checkdoc-overlay-start
  (if (featurep 'xemacs) 'extent-start 'overlay-start))
(defalias 'checkdoc-overlay-end
  (if (featurep 'xemacs) 'extent-end 'overlay-end))
(defalias 'checkdoc-mode-line-update
  (if (featurep 'xemacs) 'redraw-modeline 'force-mode-line-update))
(defalias 'checkdoc-char=
  (if (featurep 'xemacs) 'char= '=))

;;; User level commands
;;
;;;###autoload
(defun checkdoc ()
  "Interactively check the entire buffer for style errors.
The current status of the check will be displayed in a buffer which
the users will view as each check is completed."
  (interactive)
  (let ((status (list "Checking..." "-" "-" "-"))
        (checkdoc-spellcheck-documentation-flag
         (car (memq checkdoc-spellcheck-documentation-flag
                    '(buffer interactive t))))
        ;; if the user set autofix to never, then that breaks the
        ;; obviously requested asking implied by using this function.
        ;; Set it to paranoia level.
        (checkdoc-autofix-flag (if (or (not checkdoc-autofix-flag)
                                       (eq checkdoc-autofix-flag 'never))
                                   'query
                                 checkdoc-autofix-flag))
        tmp)
    (checkdoc-display-status-buffer status)
    ;; check the comments
    (if (not buffer-file-name)
        (setcar status "Not checked")
      (if (checkdoc-file-comments-engine)
          (setcar status "Errors")
        (setcar status "Ok")))
    (setcar (cdr status) "Checking...")
    (checkdoc-display-status-buffer status)
    ;; Check the documentation
    (setq tmp (checkdoc-interactive nil t))
    (if tmp
        (setcar (cdr status) (format "%d Errors" (length tmp)))
      (setcar (cdr status) "Ok"))
    (setcar (cdr (cdr status)) "Checking...")
    (checkdoc-display-status-buffer status)
    ;; Check the message text
    (if (setq tmp (checkdoc-message-interactive nil t))
        (setcar (cdr (cdr status)) (format "%d Errors" (length tmp)))
      (setcar (cdr (cdr status)) "Ok"))
    (setcar (cdr (cdr (cdr status))) "Checking...")
    (checkdoc-display-status-buffer status)
    ;; Rogue spacing
    (if (condition-case nil
            (checkdoc-rogue-spaces nil t)
          (error t))
        (setcar (cdr (cdr (cdr status))) "Errors")
      (setcar (cdr (cdr (cdr status))) "Ok"))
    (checkdoc-display-status-buffer status)))

(defun checkdoc-display-status-buffer (check)
  "Display and update the status buffer for the current checkdoc mode.
CHECK is a list of four strings stating the current status of each
test; the nth string describes the status of the nth test."
  (let (temp-buffer-setup-hook)
    (with-output-to-temp-buffer " *Checkdoc Status*"
      (princ-list
       "Buffer comments and tags:  " (nth 0 check) "\n"
       "Documentation style:       " (nth 1 check) "\n"
       "Message/Query text style:  " (nth 2 check) "\n"
       "Unwanted Spaces:           " (nth 3 check)
       )))
  (shrink-window-if-larger-than-buffer
   (get-buffer-window " *Checkdoc Status*"))
  (message nil)
  (sit-for 0))

;;;###autoload
(defun checkdoc-interactive (&optional start-here showstatus)
  "Interactively check the current buffer for doc string errors.
Prefix argument START-HERE will start the checking from the current
point, otherwise the check starts at the beginning of the current
buffer.  Allows navigation forward and backwards through document
errors.  Does not check for comment or space warnings.
Optional argument SHOWSTATUS indicates that we should update the
checkdoc status window instead of the usual behavior."
  (interactive "P")
  (let ((checkdoc-spellcheck-documentation-flag
         (car (memq checkdoc-spellcheck-documentation-flag
                    '(interactive t)))))
    (prog1
        ;; Due to a design flaw, this will never spell check
        ;; docstrings.
        (checkdoc-interactive-loop start-here showstatus
                                   'checkdoc-next-error)
      ;; This is a workaround to perform spell checking.
      (checkdoc-interactive-ispell-loop start-here))))

;;;###autoload
(defun checkdoc-message-interactive (&optional start-here showstatus)
  "Interactively check the current buffer for message string errors.
Prefix argument START-HERE will start the checking from the current
point, otherwise the check starts at the beginning of the current
buffer.  Allows navigation forward and backwards through document
errors.  Does not check for comment or space warnings.
Optional argument SHOWSTATUS indicates that we should update the
checkdoc status window instead of the usual behavior."
  (interactive "P")
  (let ((checkdoc-spellcheck-documentation-flag
         (car (memq checkdoc-spellcheck-documentation-flag
                    '(interactive t)))))
    (prog1
        ;; Due to a design flaw, this will never spell check messages.
        (checkdoc-interactive-loop start-here showstatus
                                   'checkdoc-next-message-error)
      ;; This is a workaround to perform spell checking.
      (checkdoc-message-interactive-ispell-loop start-here))))

(defun checkdoc-interactive-loop (start-here showstatus findfunc)
  "Interactively loop over all errors that can be found by a given method.

If START-HERE is nil, searching starts at the beginning of the current
buffer, otherwise searching starts at START-HERE.  SHOWSTATUS
expresses the verbosity of the search, and whether ending the search
will auto-exit this function.

FINDFUNC is a symbol representing a function that will position the
cursor, and return error message text to present to the user.  It is
assumed that the cursor will stop just before a major sexp, which will
be highlighted to present the user with feedback as to the offending
style."
  ;; Determine where to start the test
  (let* ((begin (prog1 (point)
                  (if (not start-here) (goto-char (point-min)))))
         ;; Assign a flag to spellcheck flag
         (checkdoc-spellcheck-documentation-flag
          (car (memq checkdoc-spellcheck-documentation-flag
                     '(buffer interactive t))))
         ;; Fetch the error list
         (err-list (list (funcall findfunc nil)))
         (cdo nil)
         (returnme nil)
         c)
    (save-window-excursion
      (if (not (car err-list)) (setq err-list nil))
      ;; Include whatever function point is in for good measure.
      (beginning-of-defun)
      (while err-list
        (goto-char (cdr (car err-list)))
        ;; The cursor should be just in front of the offending doc string
        (if (stringp (car (car err-list)))
            (setq cdo (save-excursion (checkdoc-make-overlay
                                       (point) (progn (forward-sexp 1)
                                                      (point)))))
          (setq cdo (checkdoc-make-overlay
                     (checkdoc-error-start (car (car err-list)))
                     (checkdoc-error-end (car (car err-list))))))
        (unwind-protect
            (progn
              (checkdoc-overlay-put cdo 'face 'highlight)
              ;; Make sure the whole doc string is visible if possible.
              (sit-for 0)
              (if (and (looking-at "\"")
                       (not (pos-visible-in-window-p
                             (save-excursion (forward-sexp 1) (point))
                             (selected-window))))
                  (let ((l (count-lines (point)
                                        (save-excursion
                                          (forward-sexp 1) (point)))))
                    (if (> l (window-height))
                        (recenter 1)
                      (recenter (/ (- (window-height) l) 2))))
                (recenter))
              (message "%s (C-h,%se,n,p,q)" (checkdoc-error-text
                                              (car (car err-list)))
                       (if (checkdoc-error-unfixable (car (car err-list)))
                           "" "f,"))
              (save-excursion
                (goto-char (checkdoc-error-start (car (car err-list))))
                (if (not (pos-visible-in-window-p))
                    (recenter (- (window-height) 2)))
                (setq c (read-event)))
              (if (not (integerp c)) (setq c ??))
              (cond
               ;; Exit condition
               ((checkdoc-char= c ?\C-g) (signal 'quit nil))
               ;; Request an auto-fix
               ((or (checkdoc-char= c ?y) (checkdoc-char= c ?f))
                (checkdoc-delete-overlay cdo)
                (setq cdo nil)
                (goto-char (cdr (car err-list)))
                ;; `automatic-then-never' tells the autofix function
                ;; to only allow one fix to be automatic.  The autofix
                ;; function will then set the flag to 'never, allowing
                ;; the checker to return a different error.
                (let ((checkdoc-autofix-flag 'automatic-then-never)
                      (fixed nil))
                  (funcall findfunc t)
                  (setq fixed (not (eq checkdoc-autofix-flag
                                       'automatic-then-never)))
                  (if (not fixed)
                      (progn
                        (message "A Fix was not available.")
                        (sit-for 2))
                    (setq err-list (cdr err-list))))
                (beginning-of-defun)
                (let ((ne (funcall findfunc nil)))
                  (if ne
                      (setq err-list (cons ne err-list))
                    (cond ((not err-list)
                           (message "No More Stylistic Errors.")
                           (sit-for 2))
                          (t
                           (message
                            "No Additional style errors.  Continuing...")
                           (sit-for 2))))))
               ;; Move to the next error (if available)
               ((or (checkdoc-char= c ?n) (checkdoc-char= c ?\s))
                (let ((ne (funcall findfunc nil)))
                  (if (not ne)
                      (if showstatus
                          (setq returnme err-list
                                err-list nil)
                        (if (not err-list)
                            (message "No More Stylistic Errors.")
                          (message "No Additional style errors.  Continuing..."))
                        (sit-for 2))
                    (setq err-list (cons ne err-list)))))
               ;; Go backwards in the list of errors
               ((or (checkdoc-char= c ?p) (checkdoc-char= c ?\C-?))
                (if (/= (length err-list) 1)
                    (progn
                      (setq err-list (cdr err-list))
                      (goto-char (cdr (car err-list)))
                      (beginning-of-defun))
                  (message "No Previous Errors.")
                  (sit-for 2)))
               ;; Edit the buffer recursively.
               ((checkdoc-char= c ?e)
                (checkdoc-recursive-edit
                 (checkdoc-error-text (car (car err-list))))
                (checkdoc-delete-overlay cdo)
                (setq err-list (cdr err-list)) ;back up the error found.
                (beginning-of-defun)
                (let ((ne (funcall findfunc nil)))
                  (if (not ne)
                      (if showstatus
                          (setq returnme err-list
                                err-list nil)
                        (message "No More Stylistic Errors.")
                        (sit-for 2))
                    (setq err-list (cons ne err-list)))))
               ;; Quit checkdoc
               ((checkdoc-char= c ?q)
                (setq returnme err-list
                      err-list nil
                      begin (point)))
               ;; Goofy stuff
               (t
                (if (get-buffer-window "*Checkdoc Help*")
                    (progn
                      (delete-window (get-buffer-window "*Checkdoc Help*"))
                      (kill-buffer "*Checkdoc Help*"))
                  (with-output-to-temp-buffer "*Checkdoc Help*"
                    (princ-list
                     "Checkdoc Keyboard Summary:\n"
                     (if (checkdoc-error-unfixable (car (car err-list)))
                         ""
                       (concat
                        "f, y    - auto Fix this warning without asking (if\
 available.)\n"
                        "         Very complex operations will still query.\n")
                       )
                     "e      - Enter recursive Edit.  Press C-M-c to exit.\n"
                     "SPC, n - skip to the Next error.\n"
                     "DEL, p - skip to the Previous error.\n"
                     "q      - Quit checkdoc.\n"
                     "C-h    - Toggle this help buffer."))
                  (shrink-window-if-larger-than-buffer
                   (get-buffer-window "*Checkdoc Help*"))))))
          (if cdo (checkdoc-delete-overlay cdo)))))
    (goto-char begin)