Isearch interaction model (was: Let's make C-M-w in isearch yank symbol, not delete character)

[Juri Linkov]

> Thanks. I'm looking for ways we can tweak the existing default interaction
> model, but I think we should take a broader look at how isearch works in
> the first place. IMHO, find-and-replace should be more closely integrated
> into isearch,

I believe we could arrive to this goal gradually by adding more isearch
features to query-replace, and query-replace features to isearch,
i.e. like digging a tunnel from both ends to meet in the middle.

As one of first simplest steps we could try to sync their keybindings
as much as possible, e.g. to add:

(define-key query-replace-map "\C-s" 'skip)
(define-key query-replace-map "\C-r" 'backup)
(define-key query-replace-map "\M-e" 'edit-replacement)
...

> we should have a unified history for regular and regex search,

Not sure about this, I thought more in the direction of adding separate
histories for word search, symbol search, to be able to repeat the last
search of the same type.  Why do you think histories should be shared?

> and case-sensitivity, symbol-granularity, regex mode, etc. should all
> be independently toggleable peer flags.

Do you mean customizing default search parameters, or keeping toggled
parameters in later searches?