Re: blank-mode.el

[Vinicius Jose Latorre]

Drew Adams wrote:
> > > User option `blank-chars' specifies which blank characters to
> > > highlight, but it would be good to also have commands to toggle
> > > each highlighting type. For example, `M-x blank-toggle-trailing'
> > > and `M-x blank-toggle-tabs'. And it would be good to have this
> > > for both local and global use: `blank-toggle-tabs-global', in
> > > addition to `blank-toggle-tabs'.
> > Hummm, maybe a better approach could be to pass a list to blank-mode or
> > blank-global-mode like:
> >
> > ; turn on local blank-mode but only highlight trailing spaces and spaces
> > before tab
> > (blank-mode '(trailing space-before-tab))
> >
> > So, the command above is the same as the following sequence:
> >
> > (blank-mode nil)
> > (setq blank-chars '(trailing space-before-tab))
> > (blank-mode t)
>
> What would that mean interactively?

Indeed, I was thinking only in terms of an ELisp code.


>                                     Would the user need to decide which
> chars to highlight each time s?he used the mode command?

Well, the user always have to decide which blank to highlight via a toggle
command interactively or via a list in an ELisp code.


>                                                          How would s?he
> specify those chars - input their names with completion?

Interactively, well, it could pass an ELisp expression, if the command uses
(interactive "X").  Hummm, this doesn't seem to be a good thing to do.


>                                                          What if s?he just
> wants the default (current) `blank-chars' - does s?he still need to specify
> all the chars to highlight when turning on the mode?

Interactively, it could pass an ELisp expression, so it could pass 
blank-chars
var as an argument.


> I don't think the choice of what to highlight should be connected with the
> mode command. That should remain a simple toggle, just turning on/off
> highlighting as specified by the current value of `blank-chars'. Much of the
> time, that will be all a user needs.
>
> I'd prefer to have a separate toggle command for each kind of blank
> highlighting - those commands would only change the value of `blank-chars'.
> That, to me, is the most convenient for the user - more convenient than
> `set-variable' or `customize-option', and more convenient that coupling
> highlighting changes with the mode command.
>
> Second best is just using `set-variable' (but that requires you to specify
> each of the chars to highlight). IIUC, least convenient of all, IMO, is
> coupling the minor-mode command with the chars choice.
>
> My suggestion lets users change the highlighting by expressing only the
> delta - not all of the chars to highlight, but just what to change.

Ok, instead of modifying blank-mode behavior passing a list,
we could have the following commands:

   blank-toggle

   blank-global-toggle

When activated interactively, it asks to user which feature to highlight
(it could be via a menu, in a similar way that C-h behaves).  The menu
options could be something like:

   t - tabs
   s - spaces and hard spaces
   r - trailing blanks
   b - spaces before tab
   l - lines
   ? - display the menu

So, if blank-toggle is binded to a key, for example, C-c b, then the 
user could
type:

   C-c b t      toggle tabs
   C-c b s      toggle spaces and hard spaces
   C-c b r      toggle trailing blanks
   C-c b b      toggle spaces before tab
   C-c b l      toggle lines

Or the user could type:

   M-x blank-toggle RET t
   M-x blank-toggle RET s
   etc.

And via ELisp code, it could pass a symbol like:

   (blank-toggle 'trailing)
   (blank-toggle 'space-before-tab)
   etc.

Also, via ELisp code, it could pass a list like:

   (blank-toggle '(trailing space-before-tab))


> Just one opinion.

Thanks for your opinion.