private Expression GetLeft(string rOperator)
{
if (StackToken.Count == 0)
{
if (rOperator == "-")
{
return(null);
}
throw new Exception($"操作符{rOperator} 参数不匹配");
}
if (StackOperator.Count == 0)
{
return(GetExpression(StackToken.Pop()));
}
var level = ExpressionOperator.GetOperatorLevel(rOperator);
var lLevel = ExpressionOperator.GetOperatorLevel(StackOperator.Peek().Value);
if (level > lLevel)
{
return(GetExpression(StackToken.Pop()));
}
var rToken = StackOperator.Pop();
ExpressionMatch rMatch = new ExpressionMatch();
rMatch.Operator = rToken.Value;
rMatch.Right = GetExpression(StackToken.Pop());
rMatch.Left = GetLeft(rMatch.Operator);
return(rMatch);
}
public override Expression Clone()
{
var expression = new ExpressionMatch();
expression.Left = Left.Clone();
expression.Right = Right.Clone();
expression.Operator = Operator;
return(expression);
}
/// <summary>
/// 解析一则表达式
/// </summary>
/// <param name="e"></param>
/// <returns></returns>
private bool Resolve_FirstOrder(out Expression e)
{
e = null;
bool firstOrder = false;
switch (Current.Value)
{
case "+":
case "-":
firstOrder = Last == null || (Last.Type == ExpressionToken.eType.Operator && Last.Value != ")");
break;
case "!":
firstOrder = true;
break;
}
if (firstOrder)
{
var tokens = new List <ExpressionToken>();
Read();
if (Current == null)
{
throw new Exception($"解析表达式异常，操作符{Last.Value}参数错误");
}
tokens.Add(Current);
var m = new ExpressionMatch()
{
Operator = Last.Value,
Left = null,
};
if (!Resolve_Identifier(out m.Right))
{
if (!Resolve_Block(out m.Right))
{
m.Right = Expression.Resolve(tokens.ToArray());
Read();
}
}
e = m;
return(true);
}
return(false);
}
/// <summary>
/// 生成表达式
/// </summary>
/// <returns></returns>
private Expression GenerateSubMatch()
{
ExpressionMatch rCurrentMatch = null;
if (StackOperator.Count == 0 || StackOperator.Peek().Type == ExpressionToken.eType.End)
{
if (StackToken.Count == 1)
{
return(GetExpression(StackToken.Pop()));
}
throw new Exception("语法解析失败");
}
while (StackOperator.Count > 0)
{
var rToken = StackOperator.Pop();
if (rToken.Type == ExpressionToken.eType.End || rToken.Value == "(")
{
break;
}
var rMatch = new ExpressionMatch();
rMatch.Operator = rToken.Value;
if (null == rCurrentMatch)
{
rMatch.Right = GetExpression(StackToken.Pop());
}
else
{
rMatch.Right = rCurrentMatch;
}
rMatch.Left = GetLeft(rMatch.Operator);
rCurrentMatch = rMatch;
}
return(rCurrentMatch);
}
