bug#9130: 23.3; Lisp mode doc string enhancment

[Stefan Monnier]

severity 9130 wishlist
tags 9130 patch
thanks

> Here is a change that enhances Lisp mode fontification to handle
> documentation of the form

>     (:documentation "the doc string")

Thanks.  That looks like a useful addition.  Could you try and make it
an actual patch (as output by `diff' and friends), also could you also
make sure your code uses a proper prefix ("lisp-") for all the functions
it defines, and finally could you make sure it's only enabled when it's
useful (I don't think we support such :documentation thingies in Elisp
(tho maybe EIEIO does) so it should only be enabled in lisp-mode but
not in emacs-lisp-mode).

There's time for that: we're in feature freeze for Emacs-24.1, so we
won't install such a change before early next year.


        Stefan


> These kinds of documentation forms are used in Common Lisp code for CLOS
> class and slot documentation.

> To apply the patch, replace lisp-font-lock-syntactic-face-function in
> share/emacs/23.3/lisp/emacs-lisp/lisp-mode.el with the three functions
> below:

> (defun string-in-doc-position-p (state)
>   (let* ((listbeg (nth 1 state))
>          (firstsym (and listbeg
>                         (save-excursion
>                           (goto-char listbeg)
>                           (and (looking-at "([ 
> \t\n]*\\(\\(\\sw\\|\\s_\\)+\\)")
>                                (match-string 1)))))
>          (docelt (and firstsym (get (intern-soft firstsym)
>                                     lisp-doc-string-elt-property))))
>     (and docelt
>          ;; It's a string in a form that can have a docstring.
>          ;; Check whether it's in docstring position.
>          (save-excursion
>            (when (functionp docelt)
>              (goto-char (match-end 1))
>              (setq docelt (funcall docelt)))
>            (goto-char listbeg)
>            (forward-char 1)
>            (condition-case nil
>                (while (and (> docelt 0) (< (point) startpos)
>                            (progn (forward-sexp 1) t))
>                  (setq docelt (1- docelt)))
>              (error nil))
>            (and (zerop docelt) (<= (point) startpos)
>                 (progn (forward-comment (point-max)) t)
>                 (= (point) (nth 8 state)))))))

> (defun string-after-documentation-keyword-p (state)
>   (and (nth 1 state)                    ; we are inside a Lisp form
>        (let ((startpos (nth 8 state)))
>          (and startpos
>               (let ((ok nil)
>                     (prevsym (save-excursion
>                                (goto-char startpos)
>                                (condition-case nil
>                                    (progn (backward-sexp 1) (setf ok t))
>                                  (error nil))
>                                (and ok
>                                     (looking-at "\\(\\sw+\\)")
>                                     (match-string 1)))))
>                 (equal prevsym ":documentation"))))))

> (defun lisp-font-lock-syntactic-face-function (state)
>   (if (nth 3 state)
>       ;; This might be a (doc)string or a |...| symbol.
>       (let ((startpos (nth 8 state)))
>         (if (eq (char-after startpos) ?|)
>             ;; This is not a string, but a |...| symbol.
>             nil
>           (if (or (string-in-doc-position-p state)
>                   (string-after-documentation-keyword-p state))
>               font-lock-doc-face
>             font-lock-string-face)))
>     font-lock-comment-face))



> In GNU Emacs 23.3.1 (x86_64-unknown-linux-gnu)
>  of 2011-07-15 on paradicsom.nyc.corp.google.com
> configured using `configure  '--prefix' 
> '/local/software/package/emacs-23.3.1' '--without-x''

> Important settings:
>   value of $LC_ALL: nil
>   value of $LC_COLLATE: C
>   value of $LC_CTYPE: nil
>   value of $LC_MESSAGES: nil
>   value of $LC_MONETARY: C
>   value of $LC_NUMERIC: C
>   value of $LC_TIME: C
>   value of $LANG: en_US.UTF-8
>   value of $XMODIFIERS: nil
>   locale-coding-system: utf-8-unix
>   default enable-multibyte-characters: t

> Major mode: Emacs-Lisp

> Minor modes in effect:
>   file-name-shadow-mode: t
>   global-font-lock-mode: t
>   font-lock-mode: t
>   auto-encryption-mode: t
>   auto-compression-mode: t
>   line-number-mode: t

> Recent input:
> ESC [ > 1 ; 2 3 0 5 ; 0 c C-x C-f . e m a c s RET C-v 
> C-v C-v C-v C-v C-v C-v C-v C-v C-v C-v C-v ESC v ESC 
> v ESC v ESC v ESC v ESC v C-v C-v C-v C-v C-a C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-l C-v C-v C-v ESC v ESC v ESC v ESC v ESC v ESC v 
> ESC v ESC v ESC v ESC v ESC v ESC v ESC v ESC v ESC 
> v ESC v ESC v C-v C-l C-u C-u C-n C-n C-n DEL C-x SPC 
> SPC C-a C-x C-s C-v C-x C-s C-v C-v C-v C-v ESC v C-v 
> C-n C-n C-n C-n C-n C-n C-n C-n C-l C-u C-p C-p C-p 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n 
> C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-l ESC 
> x r e p o r t - e m a c s - b u g RET

> Recent messages:
> ("emacs")
> Loading /local/software/source-trees/emacs-jabber/jabber-autoloads.el 
> (source)...done
> call-interactively: Beginning of buffer [3 times]
> Saving file /home/brown/.emacs...
> Wrote /home/brown/.emacs
> (No changes need to be saved)

> Load-path shadows:
> /local/software/source-trees/cc-mode/cc-fonts hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-fonts
> /local/software/source-trees/cc-mode/cc-align hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-align
> /local/software/source-trees/cc-mode/cc-menus hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-menus
> /local/software/source-trees/cc-mode/cc-engine hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-engine
> /local/software/source-trees/cc-mode/cc-mode hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-mode
> /local/software/source-trees/cc-mode/cc-awk hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-awk
> /local/software/source-trees/cc-mode/cc-defs hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-defs
> /local/software/source-trees/cc-mode/cc-vars hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-vars
> /local/software/source-trees/cc-mode/cc-styles hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-styles
> /local/software/source-trees/cc-mode/cc-bytecomp hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-bytecomp
> /local/software/source-trees/cc-mode/cc-compat hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-compat
> /local/software/source-trees/cc-mode/cc-cmds hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-cmds
> /local/software/source-trees/cc-mode/cc-langs hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/progmodes/cc-langs
> /local/software/package/org-5.13e/org-publish hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/org/org-publish
> /local/software/package/org-5.13e/org hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/org/org
> /local/software/package/org-5.13e/org-install hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/org/org-install
> /local/software/package/org-5.13e/org-mouse hides 
> /local/software/package/emacs-23.3.1/share/emacs/23.3/lisp/org/org-mouse

> Features:
> (shadow sort mail-extr message ecomplete rfc822 mml easymenu mml-sec
> password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
> rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
> time-date mm-util mail-prsvr gmm-utils wid-edit mailheader canlock sha1
> hex-util hashcash mail-utils warnings emacsbug uniquify advice help-fns
> advice-preload slime-autoloads regexp-opt cl cl-19 ediff-hook vc-hooks
> lisp-float-type lisp-mode register page menu-bar rfn-eshadow timer
> jit-lock font-lock syntax facemenu font-core frame cham georgian
> utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
> japanese hebrew greek romanian slovak czech european ethiopic indian
> cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
> loaddefs button minibuffer faces cus-face files text-properties overlay
> md5 base64 format env code-pages mule custom widget
> hashtable-print-readable backquote make-network-process multi-tty emacs)