[MLton] List comprehensions?

[Florian Weimer]

>> Well, generally speaking, they give you the same general abstraction 
>> facility on the module level, that functional programmers wouldn't want to 
>> miss on the term level. Granted, you will only rarely need this. But if you 
>> look at the C++ template library, there actually are some uses of similar 
>> constructions (which in C++ materialise as so-called template template 
>> arguments).
>
> Actually I don't think anyone uses them,

I've used them to pass type traits which describe the serialization of
primitive types in a serialization library.