public int GetPrecedence()
{
switch (_type)
{
case TokenType.Negation:
return 4;
case TokenType.Exponentiation:
return 3;
case TokenType.Multiplication:
case TokenType.Division:
case TokenType.Modulus:
return 2;
case TokenType.Addition:
case TokenType.Subtraction:
return 1;
default:
return 0;
}
}