[MLton] def-use-mode

[Matthew Fluet]

Vesa Karvonen wrote:
> I just committed (http://mlton.org/pipermail/mlton-commit/2007-January/001077.html)
> a preliminary, semi-usable version of the def-use mode I started working on a long
> time ago (http://mlton.org/pipermail/mlton/2006-April/028599.html).

Looks pretty cool.  Unfortunately, it doesn't work for me; when I try to 
load 'esml-du-mlton.el', I get:

list: Symbol's value as variable is void: font-lock-type-def-face

I think this is because I use sml-mode version 3.3(beta); I'm afraid I 
haven't been able to stomach any more recent version.