public double Visit(UnaryExpr un)
{
ils.Add(MakeListItem(un.OP));
Console.Write("( " + ((un.OP == OPERATOR.MUL) ? "mul " : "add "));
un.Right.accept(this);
Console.Write(" ) ");
return(0);
}
public double Visit(UnaryExpr un)
{
un.Right.accept(this);
if (un.OP == OPERATOR.PLUS)
{
eval_stack.Push(eval_stack.Pop());
}
else if (un.OP == OPERATOR.MINUS)
{
eval_stack.Push(-eval_stack.Pop());
}
return(Double.NaN);
}
public double Visit(UnaryExpr un)
{
un.Right.accept(this);
if (un.OP == OPERATOR.PLUS)
{
Console.Write(" + ");
}
else if (un.OP == OPERATOR.MINUS)
{
Console.Write(" - ");
}
return(Double.NaN);
}
public double Visit(UnaryExpr un)
{
if (un.OP == OPERATOR.PLUS)
{
return(+un.Right.accept(this));
}
else if (un.OP == OPERATOR.MINUS)
{
return(-un.Right.accept(this));
}
return(Double.NaN);
}
/// <summary>
///
/// </summary>
public Expr Factor()
{
TOKEN l_token;
Expr RetValue = null;
if (Current_Token == TOKEN.TOK_DOUBLE)
{
RetValue = new Number(GetNumber());
Current_Token = GetToken();
}
else if (Current_Token == TOKEN.TOK_OPAREN)
{
Current_Token = GetToken();
RetValue = Expr(); // Recurse
if (Current_Token != TOKEN.TOK_CPAREN)
{
Console.WriteLine("Missing Closing Parenthesis\n");
throw new Exception();
}
Current_Token = GetToken();
}
else if (Current_Token == TOKEN.TOK_PLUS || Current_Token == TOKEN.TOK_SUB)
{
l_token = Current_Token;
Current_Token = GetToken();
RetValue = Factor();
RetValue = new UnaryExpr(RetValue,
l_token == TOKEN.TOK_PLUS ? OPERATOR.PLUS : OPERATOR.MINUS);
}
else
{
Console.WriteLine("Illegal Token");
throw new Exception();
}
return(RetValue);
}
public double Visit(UnaryExpr un)
{
un.Right.accept(this);
// ils.Add(MakeListItem(un.OP));
return(0);
}
public static Expr ParseTwo()
{
Expr r = new UnaryExpr(new Number(10), OPERATOR.MINUS);
return(r);
}