Typechecking and _ffi

[Stephen Weeks]

> While it's easy to use SML/NJ to type-check standard Standard ML

standard Standard :-)

> code, when using MLton's FFI primitives this becomes a trickier
> situation. I've got an easy way to do this now, so I thought I might
> share it.
...

Thanks for the suggestion.  We use the same idea (with a raise) to use
SML/NJ to type check our implementation of the basis library.  If you
have the MLton sources, see bin/check-basis for the script we use.
I'll add something to the user guide about this.  BTW, you might also
look through some of the Makefiles in the MLton sources to see how we
live with both SML/NJ and MLton.

> Still looking forward to a real frontend in MLton, but this is making my
> life a lot easier in the meantime!

I'm afraid the real frontend is still nowhere in sight.  The next
release at least contains much better type error messages with source
positions, but the language being typechecked is still after
defunctorization, and so will accept many nonstandard programs.