How to translate `rx' expressions to `rx-to-string'?

[Thorsten Jolitz]

Hi List, 

this works fine
 
#+begin_src emacs-lisp
(format "%S"
   (rx bol "foo_" (+ word) eol))
#+end_src

#+results:
: "^foo_[[:word:]]+$"

but its surprisingly difficult to translate it to `rx-to-string':

#+begin_src emacs-lisp
(format "%S"
   (rx-to-string (list 'bol "foo_" '(+ word) 'eol)))
#+end_src

-> rx-form: Unknown rx form `bol'

When just using a string

#+begin_src emacs-lisp
(format "%S"
   (rx "foo_"))
#+end_src

#+results:
: "foo_"

this is ok, but different:

#+begin_src emacs-lisp
(format "%S"
   (rx-to-string "foo_"))
#+end_src

#+results:
: "\\(?:foo_\\)"

And this 

#+begin_src emacs-lisp
(format "%S"
   (rx-to-string (list "foo_" '+ 'word)))
#+end_src

or this 

#+begin_src emacs-lisp
(format "%S"
   (rx-to-string (list "foo_" '(+ word))))
#+end_src

both result in -> rx-form: Unknown rx form `foo_'

This works 

#+begin_src emacs-lisp
(format "%S"
   (rx-to-string "foo_" '(+ word)))
#+end_src

#+results:
: "foo_"

but ignores everything after the string. 

Seems I did not get the syntax for function rx-to-string yet - any hints
would be welcome.

-- 
cheers,
Thorsten