Need help with Scheme code

[Paolo Prete]

Hello all,

In order to automate the reverse process of the lilypond+javascript
snippets (write the GUI modifications of the grobs to the .ly file) I need
to make the following code work:

%%%%%%%%%%%%%%%%%%%%%%%%%
token = \tweak output-attributes  #'((id . "foobar"))

\score
{
   {
      a8 \token [ c' c' c']
   }
}

%%%%%%%%%%%%%%%%%%%%%%%%%

But it doesn't compile.
What's the right way to define the "token" variable?

Note that I can compile on 2.19.84 (but not on 2.19.55) the following code

%%%%%%%%%%%%%%%%%%%%%%%%%

\score
{
   {
      a8 \tweak output-attributes  #'((id . "foobar")) [ c' c' c']
   }
}

%%%%%%%%%%%%%%%%%%%%%%%%%

In addition: how can replace "foobar" with a global variable (string +
number) that is incremented at each call of "token"  ?
The ids must be: foobar_1, foobar_2  etc.

Thanks,
Paolo