[MLton] can mlbasis rename the top-level?

[Stephen Weeks]

> The "_end" looks ugly to me.  I'd go the extra mile with the MLB lexer 
> counting SML blocks in <program>; it's close to what is done counting 
> nested SML comments, though you need to accumulate the whole string.

Handling SML blocks seems appreciably harder to me, because you
actually have to tokenize the SML.  Handling comments just requires
looking for "(*" and "*)".

> Another, reason to use "{<{" and "}>}" is that there is some hope of 
> (easily) combining that with sml-mode and Vesa's mlb mode.

Good point.  Although I'm sure that any day now Vesa will produce for
us an in-every-way-superior SML mode :-).