Function parameter order

[Tim Peierls]

On Mon, Nov 12, 2012 at 10:34 PM, Sam Pullara <spullara at gmail.com> wrote:

> This proposal makes a lot of sense to me. Not sure how nice it will look
> in the APIs that use them but it will be obvious what is going on and
> matches my expectations on type ordering.
>

Mine, too, mostly. It took me a little while to understand that T2 is short
for ObjectObject, and that Object marks a slot to be specified via the type
parameters, in left-to-right order. I was also a little confused initially
by the omission of a ToObject when no primitive types are involved.

What would lower the entry barrier, I think, would be to use a name for
slots that isn't already a valid actual type parameter. "Ref" would work
nicely; it's short and accurate.

So I'd prefer Function.RefRef.ToRef<String, Pattern, Iterable<String>>
rather than the shorter Function.T2<String, Pattern, Iterable<String>>.

For very common cases, you could have Function<F, T> extend
Function.Ref.ToRef<F, T> (currently Function.T1<F, T>) and Predicate<T>
extend Predicate.T1<T>. (I have to confess that my main reason for wanting
this is to avoid having to change my existing code. :-)  )

--tim