Re: Doc of deprecated INITIAL-INPUT arg of completing-read

[Tim Landscheidt <tim@tim-landscheidt.de>]

Stefan Monnier <monnier@iro.umontreal.ca> wrote:

>> The docstring for completing-read (GNU Emacs 28.3) says re-
>> garding INITIAL-INPUT:

>> | If INITIAL-INPUT is non-nil, insert it in the minibuffer initially,
>> |   with point positioned at the end.  If it is (STRING . POSITION), the
>> |   initial input is STRING, but point is placed at _zero-indexed_
>> |   position POSITION in STRING.  (*Note* that this is different from
>> |   ‘read-from-minibuffer’ and related functions, which use one-indexing
>> |   for POSITION.)  This feature is deprecated--it is best to pass nil
>> |   for INITIAL-INPUT and supply the default value DEF instead.  The
>> |   user can yank the default value into the minibuffer easily using
>> |   M-n.

>> If one follows this recommendation (setting INITIAL-INPUT to
>> nil and passing the original value as DEF), the user is not
>> made aware of the original INITIAL-INPUT value until he
>> presses M-n.

> Oh, you mean we should add that the default should be passed to
> `format-prompt`?  I guess that would help, indeed.

Yes.  (I doubt, though, that my brain can ever be trained to
find it convenient that pressing RET at position B will make
Emacs use the text displayed at position A, and this text at
position B will not go away if I tell Emacs that I want to
enter something different so that I can remember that if I
delete all text and press RET, it will use the text at posi-
tion A again.)

> […]

>> But even in the basic case of C-x C-f, if I want to find a file
>> upwards of default-directory, the two extra keystrokes harmonize
>> well with wanting to do something different, so it never occured to me
>> that Emacs should protect me from them.

> 🙂

> FWIW, it's almost never necessary in `C-x C-f` since you can type `../`
> to "go up", `~/` to go home, and you don't need to type anything at all to
> go back to the root.

I wasn't aware of the latter two until now, and I can't say
that the display of "~//etc/passwd" leading to visit
"/etc/passwd", but (find-file "~//etc/passwd") not working
is intuitive to me.

Tim