query-replace-regexp interactive replacement string

[suvayu ali <fatkasuvayu+linux@gmail.com>]

Hi Emacs users,

I wanted to replace interactively all numbers in the text of an org-mode
document with the number in words, so I tried:

`C-M-% [0-9]+ RET \? RET'

But this gives me an error like this:

> Debugger entered--Lisp error: (error "Invalid use of `\\' in replacement text")
>   replace-match("\\?" t nil #("2" 0 1 (fontified t)) nil)
>   match-substitute-replacement("\\?" t nil)
>   perform-replace("[0-9]+" "\\?" t t nil nil nil nil nil)
>   query-replace-regexp("[0-9]+" "\\?" nil nil nil)
>   call-interactively(query-replace-regexp nil nil)
>   recursive-edit()
>   perform-replace("[0-9]+" "?" t t nil nil nil nil nil)
>   query-replace-regexp("[0-9]+" "?" nil nil nil)
>   call-interactively(query-replace-regexp nil nil)

Since the doc string of `query-replace-regexp' says the following:

> ...
> In TO-STRING, ...
> `\?' lets you edit the replacement text in the minibuffer
> at the given position for each replacement.
> ...

I am not sure what I did wrong. I am using GNU Emacs 24.0.50.1
(x86_64-unknown-linux-gnu, GTK+ Version 2.22.0)

Thanks for any thoughts.

-- 
Suvayu

Open source is the future. It sets us free.