[MLton] Unicode / WideChar

[Henry Cejtin]

It would certainly be great to have a real Unicode WideChar.

Re most of your questions, I don't have enough experience to really say.  One
thing that I would REALLY like to be true would  be  for  none  of  these  to
depend  on  locale.   Perhaps that isn't possible, but I have definitely been
burned by this dependency.

For digits, I suspect that you really just want ASCII 0-9, but again I am not
at  all  certain.   My  notion  is that with that definition, lots of number-
cracking code could just switch to WideChar and work.

With regards to tables, I really am torn by this.  I agree that  1.1  million
bytes  is  a  bit  much.  I suspect though that it would still be the fastest
method.  This is based on the fact that at  least  for  English,  almost  all
characters  are ASCII, which means that only 128 bytes has to be in the cache
to get a VERY good hit rate.