Customizing `blink-matching-paren-distance'

Customizing `blink-matching-paren-distance'

[martin rudalics]

(defcustom blink-matching-paren-distance (* 25 1024)
   "*If non-nil, is maximum distance to search for matching open-paren."
   :type 'integer
   :group 'paren-blinking)

The doc-string implies that this variable can be nil but customize does
not permit setting it to nil.  Moreover, the doc-string should say what
happens when this variable is nil, like

(defcustom blink-matching-paren-distance (* 25 1024)
   "*If non-nil, is maximum distance to search for matching open-paren.

If nil, search stops at the begin of the accessible portion of the buffer."
   :type '(choice (const nil) integer)
   :group 'paren-blinking)

Also, users should not be allowed to enter a negative value here, but I
don't know whether there's a standard way to do this.  Writing

   :type '(choice (const nil)
                  (integer
                   :match (lambda (widget value) (>= value 0))))

causes a misleading error message when a negative value is entered.

A simple customization type like `nonnegative-integer' would be probably
the right thing.  But this might lead to asking for `positive-integer',
`nonnegative-number', `positive-float', ...

Re: Customizing `blink-matching-paren-distance'

[Richard M. Stallman]

    (defcustom blink-matching-paren-distance (* 25 1024)
       "*If non-nil, is maximum distance to search for matching open-paren.

    If nil, search stops at the begin of the accessible portion of the buffer."
       :type '(choice (const nil) integer)
       :group 'paren-blinking)

That seems reasonable; would someone please install it?

    Also, users should not be allowed to enter a negative value here, but I
    don't know whether there's a standard way to do this.

There is no need for that.

Re: Customizing `blink-matching-paren-distance'

[Eli Zaretskii]

> From: "Richard M. Stallman" <rms@gnu.org>
> Date: Fri, 26 Aug 2005 23:41:35 -0400
> Cc: emacs-devel@gnu.org
> 
>     (defcustom blink-matching-paren-distance (* 25 1024)
>        "*If non-nil, is maximum distance to search for matching open-paren.
> 
>     If nil, search stops at the begin of the accessible portion of the buffer."
>        :type '(choice (const nil) integer)
>        :group 'paren-blinking)
> 
> That seems reasonable; would someone please install it?

Done.  Thanks, Martin.