bug#73431: Add `setf` support for `stream.el` in ELPA

[Michael Heerdegen via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

> The only aspect of this I'd change is the first line of the doc string
> for the streams implementation: I'd make it say
>
>   Implementation of `seq-mapn' for streams.
>
> Other than that, everything looks good, and "M-x apropos" shows only
> the generic function.
>
> What problem did you try to solve?

Thanks... yes, that problem: how to avoid repeating what the docstring
of the generic already says - because that would suggest that the
implementation does something specific or differently.


But we also need to find out where these lines:

| (seq-mapn FUNCTION SEQUENCE &rest SEQUENCES) in `seq.el'.
|
| Undocumented

come from (the link to the source is broken).

And whether we can avoid these ARG0 ARG1 variable names:

| Implementations:
|
| (seq-mapn ARG0 (ARG1 stream) &rest CL--ARGS)

that are not present in the source.


Michael.