On Sun, Aug 10, 2014 at 7:59 AM, Tom <adatgyujto@gmail.com> wrote:

Yes, that would be the full realization of the idea.

Being able to select from FROM -> TO history pairs and quickly edit
them in-place if needed.

So the current FROM input field should provide access to previous
FROM -> TO pairs and handle the case when such a pair is
inputted instead of a simple FROM string.

I created a quick proof of concept implementation. It changes the behavior of the arrow keys for the query-replace(-regexp) FROM prompt. You can stll access the original behavior with M-p/n.

So when you start a query-replace and press the up arrow then search/replace history is rendered as FROM -> TO pairs. The -> marker is highlighted and intangible, the cursor jumps over it and you are free to edit the search/replace string. If you submit a FROM->TO pair from the FROM input field with RET then the replacement is started immediately. If you submit a simple string (without the marker) then it behaves as usual and asks for a TO string.

See the attached file.