public RPNVariable FindVariable(string pToken)
{
Variable var = VariableByName(pToken);
if (var != null)
{
RPNVariable result = new RPNVariable(this, RPNObjectType.Variable);
result.Name = pToken;
return(result);
}
return(null);
}
private void Factor()
{
RPNOperand operand;
RPNOperator aOperator;
switch (TokenType)
{
case RPNTokenType.Plus:
case RPNTokenType.Minus:
aOperator = new RPNOperator(Owner, RPNObjectType.Operator);
switch (TokenType)
{
case RPNTokenType.Plus:
(aOperator as RPNOperator).OperatorType = RPNTokenType.JustPlus;
break;
case RPNTokenType.Minus:
(aOperator as RPNOperator).OperatorType = RPNTokenType.JustMinus;
break;
}
aOperator.OperatorStr = Token;
NextToken();
Term();
Owner.RPNList.Add(aOperator);
break;
case RPNTokenType.StartParentheses:
NextToken();
Evaluate();
CheckToken(")");
NextToken();
break;
case RPNTokenType.SquareBracket:
RPNDataField dataField = new RPNDataField(Owner, RPNObjectType.DataField);
dataField.Field = Token;
Owner.RPNList.Add(dataField);
NextToken();
break;
case RPNTokenType.Ident:
RPNFunction func;
if (Owner.Environment != null)
{
func = Owner.Environment.FindFunction(Owner, Token.ToUpper());
}
else
{
func = null;
}
if (func != null)
{
FunctionAttribute funcAttrib = (FunctionAttribute)Attribute.GetCustomAttribute(func.GetType(), typeof(FunctionAttribute));
if (funcAttrib.ParamTypes != null && funcAttrib.ParamTypes.Length > 0)
{
NextToken();
for (int i = 0; i < funcAttrib.ParamTypes.Length; i++)
{
if (i == 0)
{
CheckToken("(");
}
else
{
CheckToken(";");
}
NextToken();
Evaluate();
}
CheckToken(")");
}
Owner.RPNList.Add(func);
}
else
{
RPNVariable var = Owner.FindVariable(Token.ToUpper());
if (var != null)
{
Owner.RPNList.Add(var);
}
else
{
throw new Exception("Unknown ident >" + Token + "< in expression >" + Owner.expression + "<.");
}
}
NextToken();
break;
case RPNTokenType.Number:
operand = new RPNOperand(Owner, RPNObjectType.Operand);
float number = float.Parse(Token);
operand.Value = (object)number;
Owner.RPNList.Add(operand);
NextToken();
break;
case RPNTokenType.String:
operand = new RPNOperand(Owner, RPNObjectType.Operand);
operand.Value = Token;
Owner.RPNList.Add(operand);
NextToken();
break;
case RPNTokenType.DateTime:
operand = new RPNOperand(Owner, RPNObjectType.Operand);
try
{
operand.Value = Convert.ToDateTime(Token);
}
catch
{
throw new Exception(Token + " is not a valid date.");
}
Owner.RPNList.Add(operand);
NextToken();
break;
case RPNTokenType.Boolean:
operand = new RPNOperand(Owner, RPNObjectType.Operand);
operand.Value = Convert.ToBoolean(Token);
Owner.RPNList.Add(operand);
NextToken();
break;
case RPNTokenType.Not:
aOperator = new RPNOperator(Owner, RPNObjectType.Operator);
aOperator.OperatorType = TokenType;
aOperator.OperatorStr = Token;
NextToken();
Factor();
Owner.RPNList.Add(aOperator);
break;
default:
UnexpectedToken();
break;
}
}