// S name from req; => S name = mapGet(req, "name");
svoid tok_getFromMap(LS tok) {
  int i;
  jreplace_dyn_allowNull(tok, "<id> <id> from <id>;",
    (_tok, start, end) -> {
      S type = tok.get(start);
      S var = tok.get(start+2);
      S map = tok.get(start+4);
      ret type + " " + var + " = mapGet(" + map + ", " + quote(var) + ");";
    });
}