Re: please implement query-exchange

[Dan Jacobson]

Um fellas, where's the 'query' action of your functions?  You are
supposed to ask at each occurrence.  Otherwise call it
exchange-string, and go on to write an additional query-exchange.

With no region defined it should still do something, as query-replace
does.

And in the docstring expand "fstr" to English...

And make sure the final product gets into Emacs.