bug#49316: Add apply-partially's right version

[Michael Heerdegen]

daanturo <daanturo@gmail.com> writes:

> The author has mentioned that the reason for being a macro with extra
> parentheses was the ability to work with `eldoc`: inside the inner pair of
> parentheses, we can look at parameters suggestion which is normally
> not possible
> with `apply-partially`.
>
> `applying-partially` is bit confusing given the name of the existing
> function.
> To differentiate it, can we name this macro differently? Like
> `any-partial-application`, `partially-apply-at_`, etc.

I don't insist on the name, I used just some random different name.

There are several advantages of a macro here: the parameters can be
processed at compile-time, generating slightly nicer code.  And the
programmer doesn't need to quote the _ symbol.

But I agree that a function version would make sense, too.

Michael.