word-wrap "indentation"

[Miles Bader]

I'm trying to use the new word-wrap feature to get dynamic 
wrapping in rcirc buffers (since the wrapped portions are 
read-only the lack of "visual" line movement isn't such a big 
deal).   just doing:   (set (make-local-variable 'rcirc-fill-flag) 
nil) (push '(continuation) fringe-indicator-alist) (setq word-wrap 
t)  gets decent results, but I'd really like to get something more 
similar to rcirc's normal (static) filling, which looks like: 
13:44 Wyzard: In the case of nVidia, yes
  13:44 Wyzard: If you had, say, a Matrox card, you'd be using 
                Mesa's libGL, which would talk to the Matrox DRM 
                module in the kernel, to tell the hardware to 
                draw stuff
  13:44 enouf: i mean, it makes/uses/loads it's own built kernel 
               module, as you mentioned, which is binary blob 
               related

So obviously what's needed is someway to tell the display word-wrapping
a string to insert after each wrap-point.

To exactly emulate rcirc's static filling, this would need to be a
text-property or something, but it seems useful to support a buffer-wide
variable as well.

Possible names for this variable/property could be "wrap-indent" or
"after-wrap-wring" (it seems useful to allow either a string or an
integer number of columns to me...).

Any comments?  Anyone already hacking on this sort of thing, or should I
give it a go?

-Miles

--
Guilt, n. The condition of one who is known to have committed an indiscretion,
as distinguished from the state of him who has covered his tracks.