code: Expr incDec() {
  		Expr expr = staticMember();
  		Tok tok = peek();
  		if (tok.sym == Sym.INC || tok.sym == Sym.DEC) {
  			move();
  			return new IncDec(tok.sym, true, expr, location);
  		}
  		
  		return expr;
  	}
docs: incDec : expr ('++' | '--')