[MLton] Unicode... again

[Matthew Fluet]

>> It would be nice to be able to use ml-ulex with your proposed unicode
>> library. For the first step I'll try to compile ml-ulex with mlton.
> 
> That's great! Is it backwards compatible with the existing lex used in 
> MLton?

I believe that there is an ml-lex compatibility mode; indeed, on the 
earlier version I used, I was able to use it as a drop-in replacement 
for ml-lex.

But, of course, as soon as you start making use of the unicode elements, 
something in the interface needs to change.