set flag ShuntingYardParser_debug.

svoid test_ShuntingYardParser() {
  test_ShuntingYardParser(s -> ShuntingYardParser(s/S)!);
}

svoid test_ShuntingYardParser(IF1<S, LS> parse) {
  testFunctionValues(,
    "1+2*3", ll("1", "2", "3", "*", "+"),
    "-3e2", ll("3e2", "u-"),
    "-(1+2)", ll("1", "2", "+", "u-"),
  );
}