// ----------------------------------------------------------
// private
// ----------------------------------------------------------
private void Verify(XTFormulaParser parser, XTFormulaToken token)
{
XTOperatorToken optToken = token as XTOperatorToken;
if (this.m_currIsOpt == null) // 第一个元素
{
this.m_currIsOpt = false;
if (optToken == null)
{
return; // 不是运算符
}
this.m_currIsOpt = true;
if (optToken.AllowEmptyLToken)
{
return; // 允许空左子树的运算符
}
parser.RaiseFormulaException(); // 以双目运算符开头（语法错误）
}
else if (this.m_currIsOpt == true) // 前一个元素是运算符
{
if (optToken != null) // 紧接着又是一个运算符
{
parser.RaiseFormulaException(); // 两个双目运算符连一起（语法错误）
}
this.m_currIsOpt = false;
}
else // 前一个元素是值元素
{
if (optToken == null) // 紧接着又一个值元素（语法错误）
{
parser.RaiseFormulaException();
}
this.m_currIsOpt = true;
}
}
// 解释嵌套表达式
private XTFormula Parse(HashSet <string> argNames, XTFormula formula)
{
XTFormulaToken token = null;
while (this.CurrChar() > 0)
{
token = null;
foreach (XTFormulaTokenParser parser in m_tokenParsers)
{
token = parser.Parse(this, argNames);
if (token == null)
{
continue;
}
formula.AddToken(this, token);
break;
}
if (token == null)
{
break;
}
}
if (!formula.IsVaild)
{
this.RaiseFormulaException();
}
return(formula);
}
// -------------------------------------------
// 添加节点，并调整语法树
public XTFormulaToken AddToken(XTFormulaToken token)
{
if (token is XTOperatorToken)
{
return(this.AddOptToken((XTOperatorToken)token));
}
return(this.AddValueToken(token));
}
private readonly HashSet <string> m_argNames; // 公式中实际包含的所有参数
internal XTFormula(string formula, HashSet <string> argNames)
{
this.m_formula = formula;
this.m_root = null;
this.m_currIsOpt = null;
this.m_result = null;
this.m_argNames = argNames;
}
public override XTFormulaToken Parse(XTFormulaParser parser, HashSet <string> argNames)
{
foreach (NumericParser func in sm_parsers)
{
XTFormulaToken token = func(parser, argNames);
if (token == null)
{
continue;
}
return(token);
}
return(null);
}
// ----------------------------------------------------------
// private
// ----------------------------------------------------------
private XTFormulaToken AddValueToken(XTFormulaToken token)
{
XTOperatorToken rToken = this;
while (true)
{
if (rToken.m_rToken is XTOperatorToken)
{
rToken = rToken.m_rToken as XTOperatorToken;
}
else
{
rToken.m_rToken = token;
break;
}
}
return(this);
}
// ----------------------------------------------------------
// internal
// ----------------------------------------------------------
internal virtual void AddToken(XTFormulaParser parser, XTFormulaToken token)
{
this.Verify(parser, token);
XTOperatorToken optToken = token as XTOperatorToken;
if (this.m_root == null)
{
this.m_root = token;
}
else if (this.m_root is XTOperatorToken) // 重新调整语法树
{
this.m_root = ((XTOperatorToken)this.m_root).AddToken(token);
}
else if (optToken != null)
{
optToken.SetLToken(this.m_root);
this.m_root = optToken;
}
else
{
parser.RaiseFormulaException();
}
}
private XTFormulaToken m_rToken; // 右表达式
public XTOperatorToken(Operator opt)
{
this.m_opt = opt;
this.m_lToken = null;
this.m_rToken = null;
}
// ----------------------------------------------------------
// public
// ----------------------------------------------------------
// 添加左节点
public void SetLToken(XTFormulaToken token)
{
this.m_lToken = token;
}