Re: visible-whitespace-mode

[Miles Bader]

Richard Stallman <address@hidden> writes:
> There is already a feature show-trailing-whitespace
> which does something similar.  I think it is better to extend that
> that to make a completely different feature.

I think from a user's point of view, if they want to make all whitespace
`visible', it doesn't make much sense to tell them "simply set
show-trailing-whitespace to 'all"; the name of the variable
`show-trailing-whitespace' is simply too specific.  [and this particular
request is quite common on the emacs support groups]

The next question is, would it make sense to have visible-whitespace-mode
be a wrapper that uses `show-trailing-whitespace' internally to do it's work?

I don't think it does.  show-trailing-whitespace is a built-in feature
of the display engine, that changes the _face_ of trailing whitespace.
visible-whitespace-mode, on the other hand changes the display-table to
add a visual-marker to each whitespace character (and this property is
important, because it makes adjacent whitespace characters easily
distinguishable).

>From a quick look at the implementation of show-trailing-whitespace, it
seems as if it would be fairly difficult to extend it to do what
visible-whitespace-mode does, and certainly much harder than simply
using the display-table.

-Miles
-- 
Quidquid latine dictum sit, altum viditur.