I\'d be happy to have very soft character \">>\" instead of white-space, like this:
Mono develop http://primates.ximian.com/~miguel/pictures/Valabinding-classpad.png
Use "M-:" (M-x eval-expression) and enter the following expression:
(let ((d (make-display-table))) (aset d 9 (vector ?> ?>)) (set-window-display-table nil d))
To get back to normal enter:
(set-window-display-table nil nil)