//含参构造函数
public Token(Common.TokenType type, string lexeme, double value, Common.FuncPtr func)
{
Type = type;
Lexeme = lexeme;
Value = value;
Func = func;
}
//生成语法树的一个节点
static ExprNode MakeExprNode(Common.TokenType opcode, params Object[] exprNodes)
{
ExprNode exprPtr = new ExprNode {
OpCode = opcode
};
switch (opcode)
{
case Common.TokenType.ConstId:
exprPtr.CaseConst = (double)exprNodes[0];
break;
case Common.TokenType.T:
exprPtr.CaseParmPtr = Common.Change;
break;
case Common.TokenType.Func:
exprPtr.MathFuncPtr = (Common.FuncPtr)exprNodes[0];
exprPtr.Child = (ExprNode)exprNodes[1];
break;
default:
exprPtr.Left = (ExprNode)exprNodes[0];
exprPtr.Right = (ExprNode)exprNodes[1];
break;
}
return(exprPtr);
}
Windows.UI.Xaml.DataTemplate SelectTemplateCore(object item, Windows.UI.Xaml.DependencyObject container)
{
DisplayExpressionToken token = (DisplayExpressionToken)(item);
if (token != null)
{
Common.TokenType type = token.Type;
switch (type)
{
case TokenType.Operator:
return(m_operatorTemplate);
case TokenType.Operand:
return(m_operandTemplate);
case TokenType.Separator:
return(m_separatorTemplate);
default:
throw new Exception("Invalid token type");
}
}
return(m_separatorTemplate);
}
//匹配记号
private static void MatchToken(Common.TokenType theToken)
{
if (_token.Type != theToken)
{
SyntaxError(2);
}
FetchToken();
}
//Term的递归子程序
private static ExprNode Term()
{
ExprNode left = Factor();
while (_token.Type == Common.TokenType.Mul || _token.Type == Common.TokenType.Div)
{
Common.TokenType tokenTmp = _token.Type;
MatchToken(tokenTmp);
ExprNode right = Factor();
left = MakeExprNode(tokenTmp, left, right);
}
return(left);
}
//Expression的递归子程序
private static ExprNode Expression()
{
Common.Enter("Expression");
ExprNode left = Term();
while (_token.Type == Common.TokenType.Plus || _token.Type == Common.TokenType.Minus)
{
Common.TokenType tokenTmp = _token.Type;
MatchToken(tokenTmp);
ExprNode right = Term();
left = MakeExprNode(tokenTmp, left, right);
}
Common.Tree_trace(left);
Common.Back("Expression");
return(left);
}
