bug#33007: 27.0.50; Proposal for function to edit and return string

[Juri Linkov]

> * what kind of popping up of the editing buffer
> * what to name the editing buffer
> * what kind of operation to process the edited text -
>    a function (e.g. `read' in the case of editing a bookmark
>    record, `read-string' in some other contexts, etc.).
>    Maybe `read-string' by default?

read-from-minibuffer has the following arguments.  Let's see which ones
should remain for the new function with a name like read-from-buffer
that will read from the editing buffer:

  PROMPT - probably necessary to insert some explanatory text, such as
  for example the text inserted at the top of the *Completions* buffer:
  "Click on a completion to select it.
   In this buffer, type RET to select the completion near point.
   Possible completions are:"

  INITIAL-CONTENTS - an obsolete alternative to DEFAULT-VALUE;

  KEYMAP - useful to provide a special keymap in the editing buffer;

  READ - interpret the result as a Lisp object and return that object;

  HIST - not sure, what functionality should be associated with the history
  in the editing buffer;

  DEFAULT-VALUE - necessary to specify the value to return after typing
  `C-c C-c' in the empty buffer;

  INHERIT-INPUT-METHOD - necessary as well

The new arguments should be the same as currently for the function
display-buffer:

  BUFFER-OR-NAME - the name of the editing buffer;

  ACTION - display action like display-buffer-below-selected or
  display-buffer-at-bottom.