Re: isearch-allow-move [Was: isearch-allow-prefix]

[Juri Linkov]

> I think it's fine if some people want such a feature, but I don't think
> it belongs in isearch.el.  OTOH it's perfectly OK to add hooks or do
> some changes in order to make it possible to implement such a feature
> cleanly outside of isearch.el.

It is intended to replace several mostly unusable and ugly
(mis)features in isearch.el, replacing all them with
a unified and intuitive user interface:

1. Replace the hard to type key sequence `M-s C-e M-s C-e M-s C-e ...'
   that pulls consecutive lines with more usable and easy to type
   shorter key sequence `M-s C-e C-e C-e ...' that will fix bug#10654.

2. Remove such surprising and inconvenient feature as typing
   `C-f' at the end of the isearch-edit-string minibuffer to pull
   characters to the end of the minibuffer.  It will help to
   finally get rid of the command `isearch-yank-char-in-minibuffer'
   and to remove its binding `C-f' from `minibuffer-local-isearch-map',
   because now the same functionality will be available without
   such non-standard behavior, i.e. by replacing the sequence
   `C-s M-e C-f C-f C-f' with less surprising `M-s C-f C-f C-f M-e'.

3. Make the value `edit' of the option `search-exit-option' obsolete,
   i.e. currently when `search-exit-option' is `edit', then typing
   `C-s C-f C-f C-f' activates the minibuffer and pulls characters
   to the end of the minibuffer.  The proposed patch will replace this
   with `M-s C-f C-f C-f M-e'.

4. Replace unintuitive keybindings `C-M-w' (isearch-del-char) and
   `C-M-y' (isearch-yank-char) with more convenient and intuitive
   `M-s C-f C-b', thus allowing the keys `C-M-w' and `C-M-y' exit
   Isearch and execute global commands (`C-M-y' is currently unbound
   globally, but there were proposals for its global bindings).

5. Instead of adding more explicit yanking commands like
   `isearch-yank-sexp' proposed in bug#6232, it will be possible
   to just put the `isearch-allow-move' property on `forward-sexp'
   or many other motion commands.