static L<S> ctxStringProcessing(L<S> tok) {
  int i;
  while ((i = jfind(tok, "* + *")) >= 0)
    replaceTokens_reTok(tok, i, i+5,
      quote(ctxGetString(tok.get(i)) + ctxGetString(tok.get(i+4))));
  ret tok;
}