> What about overloading "apply"? In other words, "apply" would become
> the universal method to call procedures with a variable number of
> arguments (positional and keyword arguments).
>
> I find this idea intriguing. Implementing this may need identifier
> syntax, though, so that the procedure "apply" can be overloaded with a
> macro "apply".

Ordinary procedure calls (including `apply`) should be overloaded in
R7RS-large if keyword arguments are accepted into the standard. 177 has
to be portable to so many Schemes that it needs a solution where one can
just import a library without modifying the Scheme implementation (of
course, if a Scheme provides an optimized solution, so much the better).

Is it portable to override `apply` with a custom version via import?
Even if it is, it may be a bit too magic to my taste. I'd prefer the
base language to make decisions about basic syntax, and use fairly
obvious macros for extensions.