/// <summary>
/// 获取节点所对应的优先级。
/// </summary>
/// <remarks>
/// 函数节点的优先级均为 8。
/// 运算符节点的优先级为运算符对应的优先级。
/// 其他节点的优先级均为 0。
/// </remarks>
/// <param name="node">要获得优先级的节点</param>
/// <returns>节点所对应的优先级</returns>
public static int OperatorRank(CalculatorNode node)
{
if (node is FunctionCalculatorNode)
{
return(8);
}
var operator_calculator_node = node as OperatorCalculatorNode;
return(operator_calculator_node != null?OperatorRank(operator_calculator_node.Operator) : 0);
}
/// <summary>
/// 判断此节点是否左括号。
/// 此为对OperatorCalculator.IsLeftBracket的转发。
/// </summary>
/// <param name="node">要判断的节点</param>
/// <returns>一个值，指示此节点是否优先级。</returns>
public static bool IsLeftBracket(this CalculatorNode node)
{
return(OperatorCalculatorNode.IsLeftBracket(node));
}
/// <summary>
/// 获取节点所对应的优先级。
/// 此为对 OperatorCalculator.OperatorRank 的转发。
/// </summary>
/// <param name="node">要获得优先级的节点</param>
/// <returns>节点所对应的优先级</returns>
public static int Rank(this CalculatorNode node)
{
return(OperatorCalculatorNode.OperatorRank(node));
}
/// <summary>
/// 判断此节点是否左括号。
/// </summary>
/// <param name="node">要判断的节点</param>
/// <returns>一个值，指示此节点是否优先级。</returns>
public static bool IsLeftBracket(CalculatorNode node)
{
var operator_calculator_node = node as OperatorCalculatorNode;
return(operator_calculator_node != null && operator_calculator_node.Operator == '(');
}