svoid tok_moduleClassDecls(L<S> tok) {
  jreplace(tok, "module <id> implements", "module $2 extends DynModule implements");
  jreplace(tok, "module <id> {", "module $2 extends DynModule {");
  jreplace(tok, "module {", "module " + stefansOS_defaultModuleClassName() + " {");
  jreplace(tok, "module > <id>", "module " + stefansOS_defaultModuleClassName() + " > $3");
  int i = -1;
  while ((i = jfind(tok, i+1, "module <id>",
    // check for interference with other productions
    (_tok, nIdx) -> !eqGetOneOf(_tok, nIdx+3, "instanceof", "default", "aka"))) >= 0) {
    int j = findEndOfBlock(tok, indexOf(tok, "{", i))-1;
    S name = tok.get(i+2);
    tok.set(i, "sclass");
    tokAppend(tok, j, "\nsbool _moduleClass_" + name + " = true;"); // just a marker to quickly find module classes
    reTok(tok, j, j+1);
  }
}