bug#59934: 28.2; Doc strings of `(kill|delete)-matching-lines'

[Juanma Barranquero]

The docstring of `kill-matching-lines' already says (just at the end):

  If you merely want to delete the lines, without adding them to
  the kill ring, the M-x flush-lines command is faster.

but the one for `delete-matching-lines'/`flush-lines' does not mention the kill- version.

On Fri, Dec 9, 2022 at 11:52 PM Drew Adams <drew.adams@oracle.com> wrote:

These two doc strings are _very_ similar.  The two commands are
presumably nearly the same, the difference being that one kills
to the `kill-ring' and the other just deletes.

Please consider, in each of these doc strings, adding a reference to the
other command.  E.g., "See also `<other>-matching-lines', which is
similar but <summarize the difference>."  That will make uses aware of
the existence of the other command.  Sometimes users don't consider, or
aren't even aware, of the difference between the two kinds of deletion.

You might also explicitly point out the use case for `kill-*', e.g.,
when giving the summary in the "See also": killing lets you subsequently
yank the matching lines somewhere.  Doesn't hurt to point this out
briefly.

In GNU Emacs 28.2 (build 2, x86_64-w64-mingw32)
 of 2022-09-13 built on AVALON
Windowing system distributor 'Microsoft Corp.', version 10.0.19044
System Description: Microsoft Windows 10 Pro (v10.0.2009.19044.2251)

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 --without-compress-install CFLAGS=-O2'

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