Function type naming conventions

[Brian Goetz]

> In fact, the only type we've come across repeatedly that wants a "nice"
> name that doesn't fit into the above scheme is:
>
>    int -> T
>
> which shows up in quite a few places.  There are probably a few others
> but this is the biggest.  (We also came across a desire for (T,int)->T
> in the reducer work, but that shows up in only one place.)
>
> We could treat int -> R as a specialization of Function<T,R>, and extend
> the naming convention to handle it, or we could try to come up with a
> new top-level name for it.

We can extend the existing naming convention to consistently handle this by:

   Function<T,R>      // T -> R
   IntTFunction<T>    // T -> int

This is consistent with the existing convention, in that we are 
specializing all arguments, and then "unspecializing" the second with T.

Similarly, the example that shows up in reducing integers, where we want 
(T,int)->void, would be TIntBiBlock<T>

Alternately we could be more cryptic and do

   TIFunction
   TIBiBlock

using one-letter codes for each.

Not beautiful, but workable in the relatively few cases where it shows up?