Re: [WIP PATCH] Controlling Isearch from the minibuffer

[Juri Linkov <juri@linkov.net>]

> I mean keyboard quit.  You can see the error message by evaluating this
> and then pressing C-g:
>
>     (add-hook 'post-command-hook
>               (lambda () (read-from-minibuffer "test")) t t)

It's possible to handle C-g when needed:

  (add-hook 'post-command-hook
            (lambda () (condition-case nil
                           (read-from-minibuffer "test")
                         (quit)))
            t t)

> Using a timer with zero delay instead works better.

Using a timer is still a hack.  What could avoid a hack is
using the existing solution like recursive-edit is called
at the end of isearch-mode.

> Setting `isearch-message-function' is of no help, because there are some
> tests for `(null isearch-message-function)' as well as some explicit
> calls to `(isearch-message)' in isearch.el.  As far as I can see, there
> is no alternative to modifying the function `isearch-message' itself.

Tests for `(null isearch-message-function)' were added as a temporary
workaround until lazy count will be implemented in the minibuffer.
We need to remove these workarounds anyway.  So using isearch-message-function
should be the right thing to do.

> Moreover, one still has to manually keep a list of commands that need to
> switch to the search buffer (cf. `isearch-edit--buffer-commands') and
> commands that end the search (cf. `isearch-edit--quitting-commands'); I
> see no way around that.  Therefore, I see no advantage here over the
> proposed `with-isearch-window' macro.

There is no need to keep commands in a list.  The isearch-allow-scroll
feature uses symbol properties like

  (put 'recenter 'isearch-scroll t)
  (put 'recenter-top-bottom 'isearch-scroll t)
  (put 'reposition-window 'isearch-scroll t)

> I admit that the `with-isearch-window-quitting-edit' macro of my old
> patch seems pretty ad-hoc.  However, it could be replaced by a
> `with-isearch-done' macro which is of more general nature.  If you
> search isearch.el for calls to `isearch-done', you'll see that some are
> of the form
>
>      (let (;; Set `isearch-recursive-edit' to nil to prevent calling
>            ;; `exit-recursive-edit' in `isearch-done' that terminates
>            ;; the execution of this command when it is non-nil.
>            ;; We call `exit-recursive-edit' explicitly at the end below.
>            (isearch-recursive-edit nil))
>        (isearch-done nil t)
>
> while a few others seem to just don't take into account that we may be
> ending a recursive edit.

Indeed, this is an old unsolved problem, and setting isearch-recursive-edit
to prevent calling exit-recursive-edit is a workaround.  We need to fix this
anyway.  Then calling isearch-edit-string with read-from-minibuffer
at the end of isearch-mode should not be different from the current
calling of recursive-edit at the end of isearch-mode.
Both problems will use the same solution.

> So an `with-isearch-done' macro (which ends isearch, executes the body,
> then possibly ends a recursive edit, and at the same time takes care to
> unwind the minibuffer if we happen to be in `isearch-edit-string') would
> seem a reasonable addition to isearch.el.

Do you mean to pack the current isearch-recursive-edit/exit-recursive-edit
as a macro and use it in commands like isearch-query-replace, and also to
call exit-minibuffer to handle minibuffer exiting too.  This could be fine
if no better solution is found.

> Sorry for the long message :-)

It would be more appropriate to be sorry for the long patch ;-)
Usually a long patch means there are still unsolved workarounds
for old problems such as with isearch-message-function and
exit-recursive-edit above, etc.  After solving these problems
the patch should become much shorter.