/// <summary>
/// This new evaluate function includes support to assignment and short circuit of the IIF[] operand function
/// </summary>
/// <param name="RPNQueue"></param>
/// <param name="sValue"></param>
/// <param name="ErrorMsg"></param>
/// <returns></returns>
public bool Evaluate(Support.ExQueue <Parser.TokenItem> RPNQueue, out string sValue, out string ErrorMsg)
{
// initialize the outgoing variable
ErrorMsg = "";
sValue = "";
// reset the results in the token
token.LastEvaluationResult = "";
// create a stop watch to time the evaluation
//System.Diagnostics.Stopwatch evalTime = System.Diagnostics.Stopwatch.StartNew();
// make sure the otkens are valid
if (token.AnyErrors == true)
{
// the token already has an error, return the token error as the evaluator error message
ErrorMsg = token.LastErrorMessage;
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
// create the evaluation stack
Support.ExStack <Parser.TokenItem> eval = new Support.ExStack <Parser.TokenItem>(token.TokenItems.Count);
// start looping through the tokens
int count = RPNQueue.Count;
int index = 0; // the index of the curent token item in the rpn queue
while (index < count)
{
// get the next token item
Parser.TokenItem item = RPNQueue[index];
index++;
if (item.TokenDataType == Evaluation.Engine.Parser.TokenDataType.Token_DataType_Variable)
{
#region Token_DataType_Variable
// determine if we need to assign the variable represented by the token
// or the rule syntax is doing the assignment
if (item.WillBeAssigned == false)
{
// The rule syntax is not doing the assignment, we are doing it.
// lookup the value of the variable and push it onto the evaluation stack
if (token.Variables.VariableExists(item.TokenName) == true)
{
// the variable exists, push it on the stack
eval.Push(new Parser.TokenItem(token.Variables[item.TokenName].VariableValue, Parser.TokenType.Token_Operand, item.InOperandFunction));
}
else
{
// the variable does not exist...push an empty string on the stack
eval.Push(new Parser.TokenItem("", Parser.TokenType.Token_Operand, item.InOperandFunction));
}
}
else
{
// the rule syntax is doing the assignment, add the token item to the evaluation stack
eval.Push(item);
}
#endregion
}
else if (item.TokenType == Evaluation.Engine.Parser.TokenType.Token_Operator)
{
#region Token_Operator
// pop 2 items off the stack and perform the operation
// push the result back onto the evaluation stack
Parser.TokenItem rightOperand = null;
Parser.TokenItem leftOperand = null;
try {
if (eval.Count > 0)
{
rightOperand = eval.Pop();
}
if (eval.Count > 0)
{
leftOperand = eval.Pop();
}
} catch (Exception err) {
ErrorMsg = "Error in Evaluation.Engine.Evaluator.Evaluate() while popping 2 tokens for an operator: " + err.Message;
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
// double check that we got the tokens before we evaluate
if (rightOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The right operand token is null: There may be an issue with the rule syntax.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
if (leftOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The left operand token is null: There may be an issue with the rule syntax.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
// process the operator
try {
Parser.TokenItem result = null;
if (EvaluateTokens(leftOperand, rightOperand, item, out result, out ErrorMsg) == false)
{
return(false);
}
else
{
// double check that we got a result
if (result == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The result of an operator is null: There may be an issue with the rule syntax.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
else
{
eval.Push(result);
}
}
} catch (Exception err) {
ErrorMsg = "Failed to evaluate the rule expression: The result of an operator threw an error: " + err.Message;
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
#endregion
}
else if (item.TokenType == Evaluation.Engine.Parser.TokenType.Token_Operand_Function_Stop)
{
#region Token_Operand_Function_Stop
// find the start of the function by popping off items
// evaluate the function and push the result back onto the evaluation stack
// start popping items from the evaluation stack
// until we get the start of the of the operand function
int evalCount = eval.Count;
Parser.TokenItems parameters = new Parser.TokenItems(token);
try {
for (int j = 0; j < evalCount; j++)
{
Parser.TokenItem opItem = eval.Pop();
if (opItem.TokenType == Evaluation.Engine.Parser.TokenType.Token_Operand_Function_Start)
{
// we found the start of the operand function; let's evaluate it
Parser.TokenItem result = null;
EvaluateOperandFunction(opItem, parameters, out result, out ErrorMsg);
//if (EvaluateOperandFunction(opItem, parameters, out result, out ErrorMsg) == false)
// return false;
//else
//{
// make sure we got a result
if (result == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The result of an operand function is null: There may be an issue with the rule syntax.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
else
{
eval.Push(result);
}
//}
break;
}
else if (opItem.TokenType != Evaluation.Engine.Parser.TokenType.Token_Operand_Function_Delimiter)
{
// we have a parameter to the operand function
parameters.AddToFront(opItem);
}
}
} catch (Exception err) {
ErrorMsg = "Failed to evaluate the rule expression: The evaluation of an operand function threw an error: " + err.Message;
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
#endregion
}
else if (item.TokenType == Evaluation.Engine.Parser.TokenType.Token_Assignemt_Start)
{
#region Token_Assignment_Start
// assign the value to the variable
// pop 2 items off the stack - save the value into the variable
Parser.TokenItem rightOperand = null;
Parser.TokenItem leftOperand = null;
try {
if (eval.Count > 0)
{
rightOperand = eval.Pop();
}
if (eval.Count > 0)
{
leftOperand = eval.Pop();
}
} catch (Exception err) {
ErrorMsg = "Error in Evaluation.Engine.Evaluator.Evaluate() while popping 2 tokens for an operator: " + err.Message;
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
// double check that we got the tokens before we evaluate
if (rightOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The right operand token is null: There may be an issue with the rule syntax.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
if (leftOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The left operand token is null: There may be an issue with the rule syntax.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
// look for the variable and assign the value to it
if (token.Variables.VariableExists(leftOperand.TokenName) == true)
{
// the variable exists, push it on the stack
token.Variables[leftOperand.TokenName].VariableValue = rightOperand.TokenName;
}
else
{
// failed to find the variable....this is an error
ErrorMsg = "Failed to evaluate the rule expression: Failed to find the variable '" + leftOperand.TokenName + "' for the assignment.";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
#endregion
}
else if (item.TokenType == Evaluation.Engine.Parser.TokenType.Token_Operand_Function_Start)
{
#region New Short Circuit Code
// we are only short circuiting the IIF[] operand function
if (item.TokenName.Trim().ToLower() != "iif[")
{
// add the token to the evaluation stack
eval.Push(item);
}
else
{
// we found the iif statement.
// see if the iff[] operand function allows for short circuiting
if (item.CanShortCircuit == false)
{
// no short circuiting, add it to the evaluation stack
eval.Push(item);
}
else
{
////////////////////////////////////////////////
// We can short circuit this iif[] statement //
////////////////////////////////////////////////
Parser.TokenItem result = item.ShortCircuit.Evaluate(out ErrorMsg);
if (result == null)
{
// there was an error doing the short circuit
return(false);
}
else
{
// we successfully did the short circuit
eval.Push(result);
// increment the index so we skip the ] which should be the next token
index++;
}
}
}
#endregion
}
else
{
// push the item on the evaluation stack
eval.Push(item);
}
}
if (eval.Count == 1)
{
// just 1 item on the stack; should be our answer
try {
Parser.TokenItem final = eval.Pop();
sValue = final.TokenName;
// set the results in the token
token.LastEvaluationResult = sValue;
} catch (Exception err) {
ErrorMsg = "Failed to evaluate the rule expression after all the tokens have been considered: " + err.Message;
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
}
else if (eval.Count == 0)
{
// there is no result in the evaluation stack because it my have been assigned
// do nothing here
}
else
{
ErrorMsg = "Invalid Rule Syntax";
XapLogger.Instance.Error(ErrorMsg);
return(false);
}
// stop the timer
//evalTime.Stop();
//tokenEvalTime = evalTime.Elapsed.TotalMilliseconds;
// token.LastEvaluationTime = tokenEvalTime; // set this evaluation time in the token object.
return(true);
}
private void MakeRPNQueue()
{
/*
While there are tokens to be read:
Read a token.
If the token is a number, then add it to the output queue.
If the token is a function token, then push it onto the stack.
If the token is a function argument separator (e.g., a comma):
Until the topmost element of the stack is a left parenthesis, pop the element onto the output queue. If no left parentheses are encountered, either the separator was misplaced or parentheses were mismatched.
If the token is an operator, o1, then:
while there is an operator, o2, at the top of the stack, and either
o1 is associative or left-associative and its precedence is less than (lower precedence) or equal to that of o2, or
o1 is right-associative and its precedence is less than (lower precedence) that of o2,
pop o2 off the stack, onto the output queue;
push o1 onto the operator stack.
If the token is a left parenthesis, then push it onto the stack.
If the token is a right parenthesis:
Until the token at the top of the stack is a left parenthesis, pop operators off the stack onto the output queue.
Pop the left parenthesis from the stack, but not onto the output queue.
If the token at the top of the stack is a function token, pop it and onto the output queue.
If the stack runs out without finding a left parenthesis, then there are mismatched parentheses.
When there are no more tokens to read:
While there are still operator tokens in the stack:
If the operator token on the top of the stack is a parenthesis, then there are mismatched parenthesis.
Pop the operator onto the output queue.
Exit.
*/
// set the last error message
lastErrorMessage = "";
// make sure we have parsed tokens
if (this.tokenItems.Count == 0)
{
lastErrorMessage = "No tokens to add to the RPN stack";
return;
}
#region Version 4
//////////////////////////////////////////////////////////////////////////
// This version supports short curcuiting the iif[] operand function
//////////////////////////////////////////////////////////////////////////
// create the output queue...This is the final queue that is exposed through the public property
rpn_queue = new Support.ExQueue<TokenItem>(tokenItems.Count);
// create the operator stack
Support.ExStack<TokenItem> operators = new Support.ExStack<TokenItem>();
// create the operator stack for operators
Support.ExStack<TokenItem> param_operators = new Support.ExStack<TokenItem>();
// create a temporary queue for expressions that are in operand functions
Support.ExQueue<TokenItem> param_queue = new Support.ExQueue<TokenItem>();
// local variables
//int count = 0;
bool startedShortCircuit = false; // indicates if short circuit has started
TokenItem shortCircuitItem = null; // pointer to the short circuit item
IIFShortCircuitState shortCircuitState = IIFShortCircuitState.ShortCircuit_Condition; // the current parameter in the short circuit iif[] operand
int matchingSquare = 0; // used to track the number of closing square parenthesis untile the end of the short circuit item.
// create a "fake" delimiter token item
Parser.TokenItem delimiter = new TokenItem(",", TokenType.Token_Operand_Function_Delimiter, false);
// loop through all the token items
foreach (TokenItem item in tokenItems)
{
System.Diagnostics.Debug.WriteLine(item.TokenName);
switch (item.TokenType)
{
case TokenType.Token_Close_Parenthesis:
#region Token_Close_Parenthesis
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
if (param_operators.Count > 0)
{
// start peeking at the top operator
do
{
if (param_operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
param_operators.Pop();
break;
}
else
{
// pop the operator and push it on the queue
param_queue.Add(param_operators.Pop());
}
if (param_operators.Count == 0) break;
}
while (true);
}
#endregion
}
else
{
#region Operator Stack
if (operators.Count > 0)
{
// start peeking at the top operator
do
{
System.Diagnostics.Debug.WriteLine(" Peek = " + operators.Peek().TokenName);
// see what is on top of the operator stack
if (operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
operators.Pop();
break;
}
else
{
// pop the operator and push it on the queue
rpn_queue.Add(operators.Pop());
}
if (operators.Count == 0) break;
}
while (true);
}
#endregion
}
#endregion
break;
case TokenType.Token_Open_Parenthesis:
#region Token_Open_Parenthesis
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
// add open parenthesis to the operator stack
param_operators.Push(item);
#endregion
}
else
{
#region Operator Stack
// add open parenthesis to the operator stack
operators.Push(item);
#endregion
}
#endregion
break;
case TokenType.Token_Operand:
#region Token_Operand
if (item.InOperandFunction == true)
{
#region Operand Queue
param_queue.Add(item); // if token is an operand, then write it to output.
#endregion
}
else
{
#region Operand Queue
rpn_queue.Add(item); // if token is an operand, then write it to output.
#endregion
}
#endregion
break;
case TokenType.Token_Operand_Function_Delimiter:
#region Token_Operand_Function_Delimiter
// pop the operators from the parameter stack util it's empty or we get a delimiter
do
{
// check if the parameters operator stack is empty
if (param_operators.Count == 0) break;
// pop an item from the stack
Parser.TokenItem opItem = param_operators.Pop();
// if the item is a delimiter...discard it and exit loop
if (opItem.TokenType == TokenType.Token_Operand_Function_Delimiter) break;
// add the item to the paramter queue
param_queue.Add(opItem);
}
while (true);
// start removing items from the paraemters queue and add them to the RPN queue
// unill it's empty or we access an operand function start
do
{
// see if the parameter queue is empty
if (param_queue.Count == 0) break;
// get the item from the queue
Parser.TokenItem qItem = param_queue.Dequeue();
// add the item to the appropriate rpn queue
if (startedShortCircuit == true)
{
if (qItem.TokenName.Trim().ToLower() != "iif[")
{
// we are in short circuit mode
switch (shortCircuitState)
{
case IIFShortCircuitState.ShortCircuit_Condition:
shortCircuitItem.ShortCircuit.RPNCondition.Add(qItem);
break;
case IIFShortCircuitState.ShortCircuit_False:
shortCircuitItem.ShortCircuit.RPNFalse.Add(qItem);
break;
case IIFShortCircuitState.ShortCircuit_True:
shortCircuitItem.ShortCircuit.RPNTrue.Add(qItem);
break;
}
}
}
else
rpn_queue.Add(qItem);
// if the qItem is the start of another operand function, then we are done
if (startedShortCircuit == false)
{
if (qItem.TokenType == TokenType.Token_Operand_Function_Start) break;
}
}
while (true);
// push the delimiter on the parameter operator stack
param_operators.Push(item);
// add the delimiter to the queue
if (startedShortCircuit == true)
{
if (matchingSquare == 0)
{
// we are in short circuit mode
switch (shortCircuitState)
{
case IIFShortCircuitState.ShortCircuit_Condition:
shortCircuitState = IIFShortCircuitState.ShortCircuit_True;
break;
case IIFShortCircuitState.ShortCircuit_False:
// don't change state
break;
case IIFShortCircuitState.ShortCircuit_True:
shortCircuitState = IIFShortCircuitState.ShortCircuit_False;
break;
}
}
}
else
rpn_queue.Add(item);
#endregion
break;
case TokenType.Token_Operand_Function_Start:
#region Token_Operand_Function_Start
if (item.InOperandFunction == true)
{
if (item.CanShortCircuit == true)
{
// add the item to the "regular" queue
rpn_queue.Add(item);
}
else
{
#region Parameter Operand Queue
param_queue.Add(item);
// whenever we add a new operand function to the parameter queue,
// add a "fake" delimiter to the parameter operator queue
param_operators.Push(delimiter);
#endregion
}
}
else
{
#region Operand Queue
rpn_queue.Add(item); // if token is an operand function, then write it to output.
#endregion
}
// check if the item is a short circuit item
if (item.CanShortCircuit == true)
{
// start a new short circuit
startedShortCircuit = true;
shortCircuitItem = item;
shortCircuitState = IIFShortCircuitState.ShortCircuit_Condition;
}
else
{
matchingSquare++; // we have an operand function in a short citcuit IIF[] operand function
}
#endregion
break;
case TokenType.Token_Operand_Function_Stop:
#region Token_Operand_Function_Stop
if (item.InOperandFunction == true)
{
#region Parameter Queue
// pop the operators from the parameter stack util it's empty or we get a delimiter
do
{
// check if the parameters operator stack is empty
if (param_operators.Count == 0) break;
// pop an item from the stack
Parser.TokenItem opItem = param_operators.Pop();
// if the item is a delimiter...discard it and exit loop
if (opItem.TokenType == TokenType.Token_Operand_Function_Delimiter) break;
// add the item to the paramter queue
param_queue.Add(opItem);
}
while (true);
// add the square bracket to the queue
param_queue.Add(item);
// start removing items from the paraemters queue and add them to the RPN queue
// unill it's empty or we access an operand function start
do
{
// see if the parameter queue is empty
if (param_queue.Count == 0) break;
// get the item from the queue
Parser.TokenItem qItem = param_queue.Dequeue();
if (startedShortCircuit == true)
{
// we may be at the end of the short circuit....double check the state
if ((matchingSquare == 0) && (shortCircuitState != IIFShortCircuitState.ShortCircuit_False))
{
// this is a problem, we should be on the false condition by now.
lastErrorMessage = "Error parsing the iif[] short circuit operand function: Invalid format: Expecting the false condition";
return;
}
if (qItem.TokenType == TokenType.Token_Operand_Function_Stop)
{
if (matchingSquare == 0)
{
// the stop token will go in the "regualar" queue
rpn_queue.Add(qItem);
}
else
{
// this clocing token is for an operand function embedded in the iif[] short circuit.
switch (shortCircuitState)
{
case IIFShortCircuitState.ShortCircuit_Condition:
shortCircuitItem.ShortCircuit.RPNCondition.Add(qItem);
break;
case IIFShortCircuitState.ShortCircuit_False:
shortCircuitItem.ShortCircuit.RPNFalse.Add(qItem);
break;
case IIFShortCircuitState.ShortCircuit_True:
shortCircuitItem.ShortCircuit.RPNTrue.Add(qItem);
break;
}
}
}
else
{
//shortCircuitItem.ShortCircuit.RPNFalse.DeleteOnSubmit(qItem);
// this clocing token is for an operand function embedded in the iif[] short circuit.
switch (shortCircuitState)
{
case IIFShortCircuitState.ShortCircuit_Condition:
shortCircuitItem.ShortCircuit.RPNCondition.Add(qItem);
break;
case IIFShortCircuitState.ShortCircuit_False:
shortCircuitItem.ShortCircuit.RPNFalse.Add(qItem);
break;
case IIFShortCircuitState.ShortCircuit_True:
shortCircuitItem.ShortCircuit.RPNTrue.Add(qItem);
break;
}
}
}
else
rpn_queue.Add(qItem);
// if the qItem is the end of an operand function, then we are done
if (qItem.TokenType == TokenType.Token_Operand_Function_Stop) break;
}
while (true);
if (startedShortCircuit == true)
{
if (matchingSquare == 0)
{
// we are done with the short circuiting
startedShortCircuit = false;
shortCircuitItem = null;
shortCircuitState = IIFShortCircuitState.ShortCircuit_Condition;
}
else
matchingSquare--;
}
#endregion
}
else
{
#region Operand Queue
rpn_queue.Add(item); // if token is an operand function, then write it to output.
#endregion
}
#endregion
break;
case TokenType.Token_Operator:
#region Token_Operator
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
if (param_operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= param_operators.Peek().OrderOfOperationPrecedence)
{
param_queue.Add(param_operators.Pop());
}
else
break;
if (param_operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
param_operators.Push(item);
#endregion
}
else
{
#region Operator Stack
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= operators.Peek().OrderOfOperationPrecedence)
{
rpn_queue.Add(operators.Pop());
}
else
break;
if (operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
operators.Push(item);
#endregion
}
#endregion
break;
case TokenType.Token_Assignemt_Start:
#region Token_Assignemt_Start
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= operators.Peek().OrderOfOperationPrecedence)
{
rpn_queue.Add(operators.Pop());
}
else
break;
if (operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
operators.Push(item);
#endregion
break;
case TokenType.Token_Assignment_Stop:
#region Token_Assignment_Stop
// start popping items from the operator stack until we find the assignemtn start
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
TokenItem t1 = operators.Pop();
rpn_queue.Add(t1);
if (t1.TokenType == TokenType.Token_Assignemt_Start)
{
// we are all don popping operators
break;
}
if (operators.Count == 0) break;
} while (true);
}
#endregion
break;
}
}
// pop the remaining operators
int opCount = operators.Count;
for (int i = 0; i < opCount; i++) rpn_queue.Add(operators.Pop());
#endregion
#region Version 3
//////////////////////////////////////////////////////////////////////////
// This version is working good...however, it does not include
// support for short curcuiting the iif[] operand functions
//////////////////////////////////////////////////////////////////////////
/*
// create the output queue...This is the final queue that is exposed through the public property
rpn_queue = new Support.ExQueue<TokenItem>(tokenItems.Count);
// create the operator stack
Support.ExStack<TokenItem> operators = new Support.ExStack<TokenItem>();
// create the operator stack for operators
Support.ExStack<TokenItem> param_operators = new Support.ExStack<TokenItem>();
// create a temporary queue for expressions that are in operand functions
Support.ExQueue<TokenItem> param_queue = new Support.ExQueue<TokenItem>();
// local variables
int count = 0;
// create a "fake" delimiter token item
Parser.TokenItem delimiter = new TokenItem(",", TokenType.Token_Operand_Function_Delimiter, false);
// loop through all the token items
foreach (TokenItem item in tokenItems)
{
System.Diagnostics.Debug.WriteLine(item.TokenName);
switch (item.TokenType)
{
case TokenType.Token_Close_Parenthesis:
#region Token_Close_Parenthesis
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
if (param_operators.Count > 0)
{
// start peeking at the top operator
do
{
if (param_operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
param_operators.Pop();
break;
}
else
{
// pop the operator and push it on the queue
param_queue.DeleteOnSubmit(param_operators.Pop());
}
if (param_operators.Count == 0) break;
}
while (true);
}
#endregion
}
else
{
#region Operator Stack
if (operators.Count > 0)
{
// start peeking at the top operator
do
{
System.Diagnostics.Debug.WriteLine(" Peek = " + operators.Peek().TokenName);
// see what is on top of the operator stack
if (operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
operators.Pop();
break;
}
else
{
// pop the operator and push it on the queue
rpn_queue.DeleteOnSubmit(operators.Pop());
}
if (operators.Count == 0) break;
}
while (true);
}
#endregion
}
#endregion
break;
case TokenType.Token_Open_Parenthesis:
#region Token_Open_Parenthesis
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
// add open parenthesis to the operator stack
param_operators.Push(item);
#endregion
}
else
{
#region Operator Stack
// add open parenthesis to the operator stack
operators.Push(item);
#endregion
}
#endregion
break;
case TokenType.Token_Operand:
#region Token_Operand
if (item.InOperandFunction == true)
{
#region Operand Queue
param_queue.DeleteOnSubmit(item); // if token is an operand, then write it to output.
#endregion
}
else
{
#region Operand Queue
rpn_queue.DeleteOnSubmit(item); // if token is an operand, then write it to output.
#endregion
}
#endregion
break;
case TokenType.Token_Operand_Function_Delimiter:
#region Token_Operand_Function_Delimiter
// pop the operators from the parameter stack util it's empty or we get a delimiter
do
{
// check if the parameters operator stack is empty
if (param_operators.Count == 0) break;
// pop an item from the stack
Parser.TokenItem opItem = param_operators.Pop();
// if the item is a delimiter...discard it and exit loop
if (opItem.TokenType == TokenType.Token_Operand_Function_Delimiter) break;
// add the item to the paramter queue
param_queue.DeleteOnSubmit(opItem);
}
while (true);
// start removing items from the paraemters queue and add them to the RPN queue
// unill it's empty or we access an operand function start
do
{
// see if the parameter queue is empty
if (param_queue.Count == 0) break;
// get the item from the queue
Parser.TokenItem qItem = param_queue.Dequeue();
rpn_queue.DeleteOnSubmit(qItem);
// if the qItem is the start of another operand function, then we are done
if (qItem.TokenType == TokenType.Token_Operand_Function_Start) break;
}
while (true);
// push the delimiter on the parameter operator stack
param_operators.Push(item);
// add the delimiter to the queue
rpn_queue.DeleteOnSubmit(item);
#endregion
break;
case TokenType.Token_Operand_Function_Start:
#region Token_Operand_Function_Start
if (item.InOperandFunction == true)
{
#region Parameter Operand Queue
param_queue.DeleteOnSubmit(item);
// whenever we add a new operand function to the parameter queue,
// add a "fake" delimiter to the parameter operator queue
param_operators.Push(delimiter);
#endregion
}
else
{
#region Operand Queue
rpn_queue.DeleteOnSubmit(item); // if token is an operand function, then write it to output.
#endregion
}
#endregion
break;
case TokenType.Token_Operand_Function_Stop:
#region Token_Operand_Function_Stop
if (item.InOperandFunction == true)
{
#region Parameter Queue
// pop the operators from the parameter stack util it's empty or we get a delimiter
do
{
// check if the parameters operator stack is empty
if (param_operators.Count == 0) break;
// pop an item from the stack
Parser.TokenItem opItem = param_operators.Pop();
// if the item is a delimiter...discard it and exit loop
if (opItem.TokenType == TokenType.Token_Operand_Function_Delimiter) break;
// add the item to the paramter queue
param_queue.DeleteOnSubmit(opItem);
}
while (true);
// add the square bracket to the queue
param_queue.DeleteOnSubmit(item);
// start removing items from the paraemters queue and add them to the RPN queue
// unill it's empty or we access an operand function start
do
{
// see if the parameter queue is empty
if (param_queue.Count == 0) break;
// get the item from the queue
Parser.TokenItem qItem = param_queue.Dequeue();
rpn_queue.DeleteOnSubmit(qItem);
// if the qItem is the end of an operand function, then we are done
if (qItem.TokenType == TokenType.Token_Operand_Function_Stop) break;
}
while (true);
#endregion
}
else
{
#region Operand Queue
rpn_queue.DeleteOnSubmit(item); // if token is an operand function, then write it to output.
#endregion
}
#endregion
break;
case TokenType.Token_Operator:
#region Token_Operator
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
if (param_operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= param_operators.Peek().OrderOfOperationPrecedence)
{
param_queue.DeleteOnSubmit(param_operators.Pop());
}
else
break;
if (param_operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
param_operators.Push(item);
#endregion
}
else
{
#region Operator Stack
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= operators.Peek().OrderOfOperationPrecedence)
{
rpn_queue.DeleteOnSubmit(operators.Pop());
}
else
break;
if (operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
operators.Push(item);
#endregion
}
#endregion
break;
case TokenType.Token_Assignemt_Start:
#region Token_Assignemt_Start
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= operators.Peek().OrderOfOperationPrecedence)
{
rpn_queue.DeleteOnSubmit(operators.Pop());
}
else
break;
if (operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
operators.Push(item);
#endregion
break;
case TokenType.Token_Assignment_Stop:
#region Token_Assignment_Stop
// start popping items from the operator stack until we find the assignemtn start
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
TokenItem t1 = operators.Pop();
rpn_queue.DeleteOnSubmit(t1);
if (t1.TokenType == TokenType.Token_Assignemt_Start)
{
// we are all don popping operators
break;
}
if (operators.Count == 0) break;
} while (true);
}
#endregion
break;
}
}
// pop the remaining operators
int opCount = operators.Count;
for (int i = 0; i < opCount; i++) rpn_queue.DeleteOnSubmit(operators.Pop());
*/
#endregion
#region Version 2
/*
// create the output queue
rpn_queue = new Support.ExQueue<TokenItem>(tokenItems.Count);
// create the operator stack
Support.ExStack<TokenItem> operators = new Support.ExStack<TokenItem>();
// create the operator stack for operators
Support.ExStack<TokenItem> param_operators = new Support.ExStack<TokenItem>();
// create a temporary queue for expressions that are in operand functions
Support.ExQueue<TokenItem> parameter_queue = new Support.ExQueue<TokenItem>();
// local variables
int count = 0;
// loop through all the token items
foreach (TokenItem item in tokenItems)
{
//System.Diagnostics.Debug.WriteLine(item.TokenName);
switch (item.TokenType)
{
case TokenType.Token_Close_Parenthesis:
#region Parenthesis Handling
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
if (param_operators.Count > 0)
{
// start peeking at the top operator
do
{
// see what is on top of the operator stack
if (param_operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
param_operators.Pop();
break;
}
else
{
// pop the operator and push it on the queue
parameter_queue.DeleteOnSubmit(param_operators.Pop());
}
if (param_operators.Count == 0) break;
}
while (true);
}
#endregion
}
else
{
#region Operator Stack
if (operators.Count > 0)
{
// start peeking at the top operator
do
{
// see what is on top of the operator stack
if (operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
operators.Pop();
break;
}
else
{
// pop the operator and push it on the queue
rpn_queue.DeleteOnSubmit(operators.Pop());
}
if (operators.Count == 0) break;
}
while (true);
}
#endregion
}
#endregion
break;
case TokenType.Token_Open_Parenthesis:
#region Parenthesis Handling
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
// add open parenthesis to the operator stack
param_operators.Push(item);
#endregion
}
else
{
#region Operator Stack
// add open parenthesis to the operator stack
operators.Push(item);
#endregion
}
#endregion
break;
case TokenType.Token_Operand:
#region Operand Handling
if (item.InOperandFunction == true)
{
#region Operand Queue
parameter_queue.DeleteOnSubmit(item); // if token is an operand, then write it to output.
#endregion
}
else
{
#region Operand Queue
rpn_queue.DeleteOnSubmit(item); // if token is an operand, then write it to output.
#endregion
}
#endregion
break;
case TokenType.Token_Operand_Function_Start:
#region Operand Function Handling
if (item.InOperandFunction == true)
{
parameter_queue.DeleteOnSubmit(item);
}
else
{
rpn_queue.DeleteOnSubmit(item); // if token is an operand function, then write it to output.
}
#endregion
break;
case TokenType.Token_Operand_Function_Stop:
#region Operand Function Handling
if (item.InOperandFunction == true)
{
// pop the operators from the operand function parameter
count = param_operators.Count;
for (int i = 0; i < count; i++) parameter_queue.DeleteOnSubmit(param_operators.Pop());
// add the items from the temporary parameter quue to the RPN queue
count = parameter_queue.Count;
for (int i = 0; i < count; i++) rpn_queue.DeleteOnSubmit(parameter_queue[i]);
// clear the parameter queue
parameter_queue.Clear();
// add the delimiter or stop operand function
rpn_queue.DeleteOnSubmit(item);
}
else
{
rpn_queue.DeleteOnSubmit(item); // if token is an operand function, then write it to output.
}
#endregion
break;
case TokenType.Token_Operator:
#region Operator Handling
if (item.InOperandFunction == true)
{
#region Parameter Operator Stack
if (param_operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= param_operators.Peek().OrderOfOperationPrecedence)
{
parameter_queue.DeleteOnSubmit(param_operators.Pop());
}
else
break;
if (param_operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
param_operators.Push(item);
#endregion
}
else
{
#region Operator Stack
if (operators.Count > 0)
{
// peek at the top item of the operator stack
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= operators.Peek().OrderOfOperationPrecedence)
{
rpn_queue.DeleteOnSubmit(operators.Pop());
}
else
break;
if (operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
operators.Push(item);
#endregion
}
#endregion
break;
case TokenType.Token_Operand_Function_Delimiter:
#region Delimiter Handling
// pop the operators from the operand function parameter
count = param_operators.Count;
for (int i = 0; i < count; i++) parameter_queue.DeleteOnSubmit(param_operators.Pop());
// add the items from the temporary parameter quue to the RPN queue
count = parameter_queue.Count;
for (int i = 0; i < count; i++) rpn_queue.DeleteOnSubmit(parameter_queue[i]);
// clear the parameter queue
parameter_queue.Clear();
// add the delimiter or stop operand function
//rpn_queue.DeleteOnSubmit(item);
#endregion
break;
}
}
// pop the operators
int opCount = operators.Count;
for (int i = 0; i < opCount; i++) rpn_queue.DeleteOnSubmit(operators.Pop());
*/
#endregion
#region Version 1
/*
// loop through all the token items
foreach (TokenItem item in tokenItems)
{
if ((item.TokenType == TokenType.Token_Operand) && (item.InOperandFunction == false))
{
// if token is an operand, then write it to output.
rpn_queue.DeleteOnSubmit(item);
}
else if (item.TokenType == TokenType.Token_Open_Parenthesis)
{
// add open parenthesis to the operator stack
operators.Push(item);
}
else if ((item.TokenType == TokenType.Token_Operator) && (item.InOperandFunction == false))
{
#region Operator Handling
// peek at the top item of the operator stack
if (operators.Count > 0)
{
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence >= operators.Peek().OrderOfOperationPrecedence)
{
rpn_queue.DeleteOnSubmit(operators.Pop());
}
else
break;
if (operators.Count == 0) break;
} while (true);
}
// push the token to the operator stack
operators.Push(item);
#endregion
}
else if (item.TokenType == TokenType.Token_Close_Parenthesis)
{
#region Parenthesis Handling
if (operators.Count > 0)
{
do
{
// see when is on top of the operator stack
if (operators.Peek().TokenType == TokenType.Token_Open_Parenthesis)
{
// we found the matching open parenthesis...pop it and discard
operators.Pop();
break;
}
else
{
rpn_queue.DeleteOnSubmit(operators.Pop());
}
if (operators.Count == 0) break;
}
while (true);
}
#endregion
}
else if (item.TokenType == TokenType.Token_Operand_Function_Start)
{
// push the operand function onto the output queue
rpn_queue.DeleteOnSubmit(item);
}
else if ((item.TokenType == TokenType.Token_Operand_Function_Stop) || (item.TokenType == TokenType.Token_Operand_Function_Delimiter))
{
// pop the operators from the operand function parameter
int tempCount = param_operators.Count;
for (int i = 0; i < tempCount; i++) parameter_queue.DeleteOnSubmit(param_operators.Pop());
// add the items from the temporary parameter quue to the RPN queue
tempCount = parameter_queue.Count;
for (int i = 0; i < tempCount; i++) rpn_queue.DeleteOnSubmit(parameter_queue[i]);
// clear the parameter queue
parameter_queue.Clear();
// add the delimiter or stop operand function
rpn_queue.DeleteOnSubmit(item);
}
else if ((item.TokenType == TokenType.Token_Operand) && (item.InOperandFunction == true))
{
// push the parameter on the temporary parameter queue
parameter_queue.DeleteOnSubmit(item);
}
else if ((item.TokenType == TokenType.Token_Operator) && (item.InOperandFunction == true))
{
#region Operand Function Operator Handling
// peek at the top item of the operator stack
if (param_operators.Count > 0)
{
do
{
// see if the current tokens precedence is less than or equal to the tokenItem on the operator stack
if (item.OrderOfOperationPrecedence > param_operators.Peek().OrderOfOperationPrecedence)
{
parameter_queue.DeleteOnSubmit(param_operators.Pop());
}
else
break;
if (param_operators.Count == 0) break;
} while (true);
}
// push the token to the operand function operator stack
param_operators.Push(item);
#endregion
}
}
// pop the operators
int opCount = operators.Count;
for (int i = 0; i < opCount; i++) rpn_queue.DeleteOnSubmit(operators.Pop());
*/
#endregion
}
/// <summary>
/// This is called by the constructor. This new version includes support for assignment :=
/// This new version also checks for iif[ operand functions embedded within other iif[ statements
/// </summary>
private void GetTokens()
{
// local variables
ParseState parseState = ParseState.Parse_State_Operand; // start be searching for an operand
ParseState nextParseState = ParseState.Parse_State_Comment; // the next parse state after we have processed a comment
ParseState opFuncParseState = ParseState.Parse_State_Operand; // The parse state within the operand function
ParseState tempParseState = ParseState.Parse_State_Operand; // temporary variable to hold a parse state
string currentToken = "";
int parenthesisMatch = 0; // the number of open and close parenthesis should match
int squareMatch = 0; // the number of open and close square parenthesis should match
int tildaMatch = 0; // the open and close tildas should match
int quoteMatch = 0; // the open and close quotes should match
int assignmentStartCount = 0; // the number of times an assignment start operator was found;
int assignmentStopCount = 0; // the number of times an assignment stop operator was found
bool isError = false;
bool tokenCreated = false;
int operandFunctionDepth = 0; // operand function can contain operand function...This is the depth of the operand functions
// make sure we have some syntax to parse
if (String.IsNullOrEmpty(ruleSyntax) == true) return;
// create a stop watch to time the parse
System.Diagnostics.Stopwatch parseTime = System.Diagnostics.Stopwatch.StartNew();
// start at the first character
charIndex = 0;
do
{
// double check the exit condition, just in case
if (charIndex >= ruleSyntax.Length) break;
// the character to be processed
char c = ruleSyntax[charIndex];
// Increment the counter for the next character
charIndex++;
System.Diagnostics.Debug.WriteLine("c = " + c.ToString() + "\tcurrentToken = " + currentToken + "\tparse state = " + parseState.ToString() + "\tOp Parse State = " + opFuncParseState.ToString());
#region New Line and Tab check
// check for new line and tab
if ((c == '\n') || (c == '\t'))
{
// new lines and tabs are always ignored.
c = ' '; // force the new line or tab to be a space and continue processing.
}
#endregion
#region Comment Checking
// check if we are in a comment
if (parseState == ParseState.Parse_State_Comment)
{
if (c == '~')
{
// we found the end of our comment, continue with what we were looking for
parseState = nextParseState;
tildaMatch--;
}
// continue with the next item in the loop
continue;
}
else
{
if (c == '~')
{
// we found the start of a comment
tildaMatch++;
nextParseState = parseState; // save the parse state
parseState = ParseState.Parse_State_Comment;
continue; // continue with the next item in the loop
}
}
#endregion
// determine out current parse state
switch (parseState)
{
case ParseState.Parse_State_Operand:
#region Parse_State_Operand
if (c == '"')
{
#region Quote Handling
try
{
// we have a quote in an operand...This is probably the start of a string operand
quoteMatch++;
currentToken += c;
parseState = ParseState.Parse_State_Quote;
}
catch (Exception err)
{
lastErrorMessage = "Error in GetTokens() in Operand Quote Handling: " + err.Message;
return;
}
#endregion
}
else if (c == ' ')
{
#region Space Handling
try
{
// we are looking for an operand and we found a space. We are not currently looking for a closing quote.
// Assume that the space indicates that the operand is completed and we now need to look for an operator
tokenCreated = CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError) return;
if (tokenCreated == true)
{
// set the next parse state
parseState = tempParseState;
// reset the token
currentToken = "";
}
}
catch (Exception err)
{
lastErrorMessage = "Error in GetTokens() in Operand Space Handling: " + err.Message;
return;
}
#endregion
}
else if (c == '(')
{
#region Parenthesis Handling
// increment the parenthesis count
parenthesisMatch++;
// create the token
tokenCreated = CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the open parenthesis
tokenItems.Add(new TokenItem("(", TokenType.Token_Open_Parenthesis, false));
// clear the current token
currentToken = "";
// after a parenthesis we need an operand
parseState = ParseState.Parse_State_Operand;
#endregion
}
else if (c == ')')
{
#region Parenthesis Handling
// decrement the parenthesis count
parenthesisMatch--;
// create the token
tokenCreated = CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the close parenthesis
tokenItems.Add(new TokenItem(")", TokenType.Token_Close_Parenthesis, false));
// clear the current token
currentToken = "";
// after a parenthesis we need an operator
parseState = ParseState.Parse_State_Operator;
#endregion
}
else if (c == '[')
{
#region Operand Function Handling
// Check that an operand function is starting
// increment the square parenthesis count
squareMatch++;
// clean the token
currentToken = currentToken.Trim();
if (Support.DataTypeCheck.IsOperandFunction(currentToken) == true)
{
// we found the start of an operand function
// it's possible that we have operand functions within operand functions
operandFunctionDepth++;
// add the token item
currentToken += c;
tokenItems.Add(new TokenItem(currentToken, TokenType.Token_Operand_Function_Start, false));
// Indicate that we are now in a operand function
parseState = ParseState.Parse_State_OperandFunction;
// within the operand function, we are looking for an operand
opFuncParseState = ParseState.Parse_State_Operand;
// reset the token
currentToken = "";
}
else
{
// we found a square bracket but we don't have an operand function
lastErrorMessage = "Error in Rule Syntax: Found an open square parenthesis without an operand function";
return;
}
#endregion
}
else if (c == ']')
{
#region Operand Function Handling
// we should never be looking for an operand and find a ]
squareMatch--;
lastErrorMessage = "Error in Rule Syntax: Found an ] while looking for an operand.";
return;
#endregion
}
else if (c == ',')
{
#region Command Handling
// we should never be looking for an operand and find a ,
lastErrorMessage = "Error in Rule Syntax: Found a , (comma) while looking for an operand.";
return;
#endregion
}
else if (c == '-')
{
#region Negative Operands
if (String.IsNullOrEmpty(currentToken.Trim()) == true)
{
// we found a negative sign
currentToken += c;
}
else
{
// try and create the new token
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, true, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// the new tokens were created
// reset the current token
currentToken = "";
// set the next parse state
parseState = tempParseState;
}
}
#endregion
}
else if (c == ':')
{
#region Assignment handling
// we may have the start of an assignment.
// first check....the next character must be =
if (FoundAssignment() == false)
{
// nope, we did not find an assignment, this is a problem
lastErrorMessage = "Error in Rule Syntax: Found a : (colon) but did not find an assignment token.";
return;
}
assignmentStartCount++;
// since we were looking for an operand and we found a colon, we may have a current token
CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// second check....the assignment can only be made to a variable...
// therefore, the previous token must be a variable.
if (tokenItems[tokenItems.Count - 1].TokenType == TokenType.Token_Operand)
{
if (tokenItems[tokenItems.Count - 1].TokenDataType != TokenDataType.Token_DataType_Variable)
{
// assignment can only happen to a variable, we have a problem
lastErrorMessage = "Error in Rule Syntax: An assignment can only be made to a variable.";
return;
}
}
else
{
// We have an error because you can only assign to an operand variableassignment can only happen to a variable, we have a problem
lastErrorMessage = "Error in Rule Syntax: An assignment can only be made to a variable.";
return;
}
// indicates that the last token item we created will be assigned to from the rule
tokenItems[tokenItems.Count - 1].WillBeAssigned = true;
// also indicate that this token items as assignments
anyAssignments = true;
// ok, we have a valid assignment....add the token
tokenItems.Add(new TokenItem(":=", TokenType.Token_Assignemt_Start, false)); // assignments are always flagged as not in operand functions
// increment the character index so that the = from the assignment is skipped
charIndex++;
// clear the token
currentToken = "";
// after the assignment, we need an operand
parseState = ParseState.Parse_State_Operand;
#endregion
}
else if (c == ';')
{
#region Assignment Handling
assignmentStopCount++;
// we found the end of an assignment, create the assignment stop token
tokenCreated = CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the stop token
tokenItems.Add(new TokenItem(";", TokenType.Token_Assignment_Stop, false));
// reset the current token
currentToken = "";
// after the end of the assignment, we are starting over again with a new operand
parseState = ParseState.Parse_State_Operand;
#endregion
}
else
{
#region Other Handling
// try and create the new token
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, true, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// the new tokens were created
// reset the current token
currentToken = "";
// set the next parse state
parseState = tempParseState;
}
#endregion
}
#endregion
break;
case ParseState.Parse_State_OperandFunction:
#region Parse_State_OperandFunction
switch (opFuncParseState)
{
case ParseState.Parse_State_Operand:
#region Parse_State_OperandFunction, Parse_State_Operand
if (c == '"')
{
#region Quote Handling
// we have a quote in the operand function...This is probably the start of a string operand
quoteMatch++;
currentToken += c;
opFuncParseState = ParseState.Parse_State_Quote;
#endregion
}
else if (c == ' ')
{
#region Space Handling
// we are looking for an operand and we found a space. We are not currently looking for a closing quote.
// Assume that the space indicates that the operand is completed and we now need to look for an operator
tokenCreated = CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (tokenCreated == true)
{
// set the next parse state
opFuncParseState = tempParseState;
// reset the token
currentToken = "";
}
#endregion
}
else if (c == '(')
{
#region Parenthesis Handling
// increment the parenthesis count
parenthesisMatch++;
// create the token
CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the open parenthesis
tokenItems.Add(new TokenItem("(", TokenType.Token_Open_Parenthesis, true));
// clear the current token
currentToken = "";
// after a parenthesis we need an operand
opFuncParseState = ParseState.Parse_State_Operand;
#endregion
}
else if (c == ')')
{
#region Parenthesis Handling
// decrement the parenthesis count
parenthesisMatch--;
// create the token
CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the close parenthesis
tokenItems.Add(new TokenItem(")", TokenType.Token_Close_Parenthesis, true));
// clear the current token
currentToken = "";
// after a parenthesis we need an operator
opFuncParseState = ParseState.Parse_State_Operator;
#endregion
}
else if (c == '[')
{
#region Operand Function Handling
// Check that an operand function is starting
// increment the square parenthesis count
squareMatch++;
// clean the token
currentToken = currentToken.Trim();
if (Support.DataTypeCheck.IsOperandFunction(currentToken) == true)
{
// we found the start of an operand function
// it's possible that we have operand functions within operand functions
operandFunctionDepth++;
// add the token item
currentToken += c;
tokenItems.Add(new TokenItem(currentToken, TokenType.Token_Operand_Function_Start, true));
// within the operand function, we are looking for an operand
opFuncParseState = ParseState.Parse_State_Operand;
// reset the token
currentToken = "";
}
else
{
// we found a square bracket but we don't have an operand function
lastErrorMessage = "Error in Rule Syntax: Found an open square parenthesis without an operand function";
return;
}
#endregion
}
else if (c == ']')
{
#region Operand Function Handling
squareMatch--;
// we found the end of an operator function
CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the stop operand token
tokenItems.Add(new TokenItem("]", TokenType.Token_Operand_Function_Stop, true));
// decrement the operand depth
operandFunctionDepth--;
// set the parse states
//opFuncParseState = ParseState.Parse_State_Operand;
opFuncParseState = ParseState.Parse_State_Operator;
// check if we are done with operand function and now need an operator
if (operandFunctionDepth <= 0)
{
operandFunctionDepth = 0;
parseState = ParseState.Parse_State_Operator;
}
// reset the current token
currentToken = "";
#endregion
}
else if (c == ',')
{
#region Command Handling
// create a toke
CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the delimiter token
tokenItems.Add(new TokenItem(",", TokenType.Token_Operand_Function_Delimiter, true));
// reset the token
currentToken = "";
opFuncParseState = ParseState.Parse_State_Operand;
#endregion
}
else if (c == '-')
{
#region Negative operands
if (String.IsNullOrEmpty(currentToken.Trim()) == true)
{
// we found a negative sign
currentToken += c;
}
else
{
// try and create the new token
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, true, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// the new tokens were created
// reset the current token
currentToken = "";
// set the next parse state
opFuncParseState = tempParseState;
}
}
#endregion
}
else if ((c == ':') || (c == ';'))
{
#region Assignment Handling
// assignments are not allowed within operand function
lastErrorMessage = "Error in Rule Syntax: Assignments are not allowed within Operand Functions";
return;
#endregion
}
else
{
#region Other Handling
// try and create the new token
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, true, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// the new tokens were created
// reset the current token
currentToken = "";
// set the next parse state
opFuncParseState = tempParseState;
}
#endregion
}
#endregion
break;
case ParseState.Parse_State_Operator:
#region Parse_State_OperandFunction, Parse_State_Operator
if (c == '"')
{
#region Quote Handling
// we found a quote while looking for an operator...this is a problem
lastErrorMessage = "Error in Rule Syntax: Found a double quote (\") while looking for an operator.";
return;
#endregion
}
else if (c == ' ')
{
#region Space Handling
// we found a space while looking for an operator...maybe it's just white space
if (String.IsNullOrEmpty(currentToken.Trim()) == true)
{
// yep, it's just white space; it can be ignored.
currentToken = "";
}
else
{
// we found a space while looking for an operator....this is a problem because
// no operators allow for spaces.
lastErrorMessage = "Error with expression syntax: Found a space while looking for an operator";
return;
}
#endregion
}
else if (c == '(')
{
#region Parenthesis Handling
// we found an opern parenthesis while searching for an operator....that's a problem
lastErrorMessage = "Error in rule syntax: Found an open parenthesis while searching for an operator";
return;
#endregion
}
else if (c == ')')
{
#region Parenthesis Handling
// add the closed parenthesis and keep looking for the operator
parenthesisMatch--;
tokenItems.Add(new TokenItem(")", TokenType.Token_Close_Parenthesis, true));
#endregion
}
else if (c == '[')
{
#region Operand Function
// we found an open parenthesis while searching for an operator....that's a problem
lastErrorMessage = "Error in rule syntax: Found an open square parenthesis while searching for an operator";
return;
#endregion
}
else if (c == ']')
{
#region Operand Function
squareMatch--;
// we found the end of an operator function
CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the stop operand token
tokenItems.Add(new TokenItem("]", TokenType.Token_Operand_Function_Stop, true));
// decrement the operand depth
operandFunctionDepth--;
// set the parse states
opFuncParseState = ParseState.Parse_State_Operand;
// check if we are done with operand function and now need an operator
if (operandFunctionDepth <= 0)
{
operandFunctionDepth = 0;
parseState = ParseState.Parse_State_Operator;
}
// reset the current token
currentToken = "";
#endregion
}
else if (c == ',')
{
#region Command Handling
// we found a comma while searching for an operator....that's alright in an operand function
CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
// add the comma
tokenItems.Add(new TokenItem(",", TokenType.Token_Operand_Function_Delimiter, true));
// reset the token
currentToken = "";
// set the parse state
opFuncParseState = ParseState.Parse_State_Operand;
#endregion
}
else if ((c == ':') || (c == ';'))
{
#region Assignment Handling
// assignments are not allowed within operand function
lastErrorMessage = "Error in Rule Syntax: Assignments are not allowed within Operand Functions";
return;
#endregion
}
else
{
#region Other Handling
// try and create the new token
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, true, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// the new tokens were created
// reset the current token
currentToken = "";
// set the next parse state
opFuncParseState = ParseState.Parse_State_Operand;
}
#endregion
}
#endregion
break;
case ParseState.Parse_State_Quote:
#region Parse_State_OperandFunction, Parse_State_Quote
if (c == '"')
{
#region Quote Handling
quoteMatch--;
// we found the end of the qoute
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, false, true, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// set the next parse state
opFuncParseState = tempParseState;
// clear the current token
currentToken = "";
}
#endregion
}
else
{
#region Other Handling
currentToken += c;
#endregion
}
#endregion
break;
}
#endregion
break;
case ParseState.Parse_State_Operator:
#region Parse_State_Operator
if (c == '"')
{
#region Quote Handling
// we found a quote while looking for an operator...this is a problem
lastErrorMessage = "Error in Rule Syntax: Found a double quote (\") while looking for an operator.";
return;
#endregion
}
else if (c == ' ')
{
#region Space Handling
// we found a space while looking for an operator...maybe it's just white space
if (String.IsNullOrEmpty(currentToken.Trim()) == true)
{
// yep, it's just white space; it can be ignored.
currentToken = "";
}
else
{
// we found a space while looking for an operator....this is a problem because
// no operators allow for spaces.
lastErrorMessage = "Error with expression syntax: Found a space while looking for an operator";
return;
}
#endregion
}
else if (c == '(')
{
#region Parenthesis Handling
// we found an opern parenthesis while searching for an operator....that's a problem
lastErrorMessage = "Error in rule syntax: Found an open parenthesis while searching for an operator";
return;
#endregion
}
else if (c == ')')
{
#region Parenthesis Handling
parenthesisMatch--;
// add the closed parenthesis and keep looking for the operator
tokenItems.Add(new TokenItem(")", TokenType.Token_Close_Parenthesis, false));
#endregion
}
else if (c == '[')
{
#region Operand Function Handling
// we found an open parenthesis while searching for an operator....that's a problem
lastErrorMessage = "Error in rule syntax: Found an open square parenthesis while searching for an operator";
return;
#endregion
}
else if (c == ']')
{
#region operand Function Handling
// we found an closed parenthesis while searching for an operator....that's a problem
lastErrorMessage = "Error in rule syntax: Found a closed square parenthesis while searching for an operator";
return;
#endregion
}
else if (c == ',')
{
#region Comma Handling
// we found a comma while searching for an operator....that's a problem
lastErrorMessage = "Error in rule syntax: Found a comma while searching for an operator";
return;
#endregion
}
else if (c == ':')
{
#region Assignment handling
// we may have the start of an assignment.
// first check....the next character must be =
if (FoundAssignment() == false)
{
// nope, we did not find an assignment, this is a problem
lastErrorMessage = "Error in Rule Syntax: Found a : (colon) but did not find an assignment token.";
return;
}
assignmentStartCount++;
// second check....the assignment can only be made to a variable...
// therefore, the previous token must be a variable.
if (tokenItems[tokenItems.Count - 1].TokenType == TokenType.Token_Operand)
{
if (tokenItems[tokenItems.Count - 1].TokenDataType != TokenDataType.Token_DataType_Variable)
{
// assignment can only happen to a variable, we have a problem
lastErrorMessage = "Error in Rule Syntax: An assignment can only be made to a variable.";
return;
}
}
else
{
// We have an error because you can only assign to an operand variableassignment can only happen to a variable, we have a problem
lastErrorMessage = "Error in Rule Syntax: An assignment can only be made to a variable.";
return;
}
// indicates that the last token item we created will be assigned to from the rule
tokenItems[tokenItems.Count - 1].WillBeAssigned = true;
// also indicate that this token items as assignments
anyAssignments = true;
// ok, we have a valid assignment....add the token
tokenItems.Add(new TokenItem(":=", TokenType.Token_Assignemt_Start, false)); // assignments are always flagged as not in operand functions
// increment the character index so that the = from the assignment is skipped
charIndex++;
// clear the token
currentToken = "";
// after the assignment, we need an operand
parseState = ParseState.Parse_State_Operand;
#endregion
}
else if (c == ';')
{
#region End assignment handling
// we found the end of the assignment...add the token
tokenItems.Add(new TokenItem(";", TokenType.Token_Assignment_Stop, false));
assignmentStopCount++;
// clear the token
currentToken = "";
// after a closing assignment token item, we need a operand
parseState = ParseState.Parse_State_Operand;
#endregion
}
else
{
#region Other Handling
// try and create the new token
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, true, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// the new tokens were created
// reset the current token
currentToken = "";
// set the next parse state
parseState = tempParseState;
}
#endregion
}
#endregion
break;
case ParseState.Parse_State_Quote:
#region Parse_State_Quote
if (c == '"')
{
#region Quote Handling
// we found the end of the qoute
quoteMatch--;
currentToken += c;
tokenCreated = CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
if (tokenCreated == true)
{
// set the next parse state
parseState = tempParseState;
// clear the current token
currentToken = "";
}
#endregion
}
else
{
currentToken += c;
}
#endregion
break;
}
} while (charIndex < ruleSyntax.Length);
#region Final Token Handling
// see if we have a current token that needs to be processed.
currentToken = currentToken.Trim();
if (String.IsNullOrEmpty(currentToken) == false)
{
// we have a token that needs to be processed
if (currentToken == "(")
parenthesisMatch++;
else if (currentToken == ")")
parenthesisMatch--;
else if (currentToken == "[")
squareMatch++;
else if (currentToken == "]")
squareMatch--;
else if (currentToken == "~")
tildaMatch--;
else if (currentToken == "\"")
quoteMatch--;
switch (parseState)
{
case ParseState.Parse_State_Operand:
CreateTokenItem(currentToken, false, false, out tempParseState, out isError, out lastErrorMessage);
if (isError == true) return;
break;
case ParseState.Parse_State_Operator:
// there should never be an operator at the end of the rule syntax
lastErrorMessage = "Error in Rule Syntax: A rule cannot end with an operator.";
break;
case ParseState.Parse_State_Quote:
// we are looking for a closing quote
if (currentToken != "\"")
{
lastErrorMessage = "Error in RuleSyntax: Double quote mismatch.";
return;
}
else
{
// add the token as an operand
tokenItems.Add(new TokenItem(currentToken, TokenType.Token_Operand, TokenDataType.Token_DataType_String, false));
}
break;
case ParseState.Parse_State_OperandFunction:
break;
}
}
#endregion
#region RuleSyntax Validation Checks
if (parenthesisMatch != 0)
{
lastErrorMessage = "Error in RuleSyntax: There is a parenthesis mismatch.";
return;
}
if (squareMatch != 0)
{
lastErrorMessage = "Error in RuleSyntax: There is an operand function mismatch.";
return;
}
if (operandFunctionDepth > 0)
{
lastErrorMessage = "Error in RuleSyntax: There is an operand function mismatch error...Operand function depth is not zero.";
return;
}
if (tildaMatch != 0)
{
lastErrorMessage = "Error in RuleSyntax: There is a comment mismatch.";
return;
}
if (quoteMatch != 0)
{
lastErrorMessage = "Error in RuleSyntax: There is a quote mismatch.";
return;
}
if (charIndex < ruleSyntax.Length)
{
lastErrorMessage = "Error in RuleSyntax: There was a problem parsing the rule...some of the tokens were not found.";
return;
}
if (assignmentStartCount != assignmentStopCount)
{
lastErrorMessage = "Error in RuleSyntax: There was a problem parsing the rule...there was an assignment mismatch.";
return;
}
#endregion
#region Search for the iif[] operand functions that can be short circuited
// loop through all of the tokens and look for operand functions start and close
bool anyIIFOperandFuncs = false;
Support.ExStack<TokenItem> iifStack = new Support.ExStack<TokenItem>();
foreach (TokenItem item in this.tokenItems)
{
System.Diagnostics.Debug.WriteLine(item.TokenName.Trim().ToLower());
if (item.TokenType == TokenType.Token_Operand_Function_Start)
{
// push the operand on the stack
anyIIFOperandFuncs = anyIIFOperandFuncs || (item.TokenName.Trim().ToLower() == "iif[");
iifStack.Push(item);
}
else if (item.TokenType == TokenType.Token_Operand_Function_Stop)
{
// we want to "throw-away" all operand fungsction other than the iif[].
// peek at the stack and see what's on top
string peekItem = iifStack.Peek().TokenName.Trim().ToLower();
if ((peekItem == "iif[") || (peekItem == "]"))
{
// we found a complete iif[] statement
iifStack.Push(item);
}
else
{
// we have the closing bracket that is not for the iif[] statement....
// discard the closing ] and the operand function
iifStack.Pop();
}
}
}
// see if there are an iif[] operand functions
if (anyIIFOperandFuncs == true)
{
// we have iif[] operands, make sure they are NOT nested...This version does not support short circuit of nexted iif[]
do
{
TokenItem item1 = null;
TokenItem item2 = null;
if (iifStack.Count > 0) item1 = iifStack.Pop();
if (iifStack.Count > 0) item2 = iifStack.Peek();
if (item1 != null)
{
if (item1.TokenType == TokenType.Token_Operand_Function_Stop)
{
// we found a ]
if (item2 != null)
{
if (item2.TokenType == TokenType.Token_Operand_Function_Start)
{
// we found a iif[
// this can be short circuited
item2.CanShortCircuit = true;
}
}
}
}
} while (iifStack.Count > 0);
}
#endregion
#region Make the RPN Queue
// create the RPN Stack
if (this.AnyErrors == false) MakeRPNQueue();
// check that we have tokens in out RPN Queue
if (rpn_queue == null)
{
lastErrorMessage = "Error in RuleSyntax: There was a problem creating the RPN queue.";
return;
}
if (rpn_queue.Count == 0)
{
lastErrorMessage = "Error in RuleSyntax: There was a problem creating the RPN queue.";
return;
}
#endregion
// stop the timer
parseTime.Stop();
tokenParseTime = parseTime.Elapsed.TotalMilliseconds;
}
/// <summary>
/// This new evaluate function includes support to assignment and short circuit of the IIF[] operand function
/// </summary>
/// <param name="RPNQueue"></param>
/// <param name="sValue"></param>
/// <param name="ErrorMsg"></param>
/// <returns></returns>
public bool Evaluate(Support.ExQueue<Parser.TokenItem> RPNQueue, out string sValue, out string ErrorMsg)
{
// initialize the outgoing variable
ErrorMsg = "";
sValue = "";
// reset the results in the token
token.LastEvaluationResult = "";
// create a stop watch to time the evaluation
System.Diagnostics.Stopwatch evalTime = System.Diagnostics.Stopwatch.StartNew();
// make sure the otkens are valid
if (token.AnyErrors == true)
{
// the token already has an error, return the token error as the evaluator error message
ErrorMsg = token.LastErrorMessage;
return false;
}
// create the evaluation stack
Support.ExStack<Parser.TokenItem> eval = new Support.ExStack<Parser.TokenItem>(token.TokenItems.Count);
// start looping through the tokens
int count = RPNQueue.Count;
int index = 0; // the index of the curent token item in the rpn queue
while (index < count)
{
// get the next token item
Parser.TokenItem item = RPNQueue[index];
index++;
System.Diagnostics.Debug.WriteLine(item.TokenName);
if (item.TokenDataType == Parser.TokenDataType.Token_DataType_Variable)
{
#region Token_DataType_Variable
// determine if we need to assign the variable represented by the token
// or the rule syntax is doing the assignment
if (item.WillBeAssigned == false)
{
// The rule syntax is not doing the assignment, we are doing it.
// lookup the value of the variable and push it onto the evaluation stack
if (token.Variables.VariableExists(item.TokenName) == true)
{
// the variable exists, push it on the stack
eval.Push(new Parser.TokenItem(token.Variables[item.TokenName].VariableValue, Parser.TokenType.Token_Operand, item.InOperandFunction));
}
else
{
// the variable does not exist...push an empty string on the stack
eval.Push(new Parser.TokenItem("", Parser.TokenType.Token_Operand, item.InOperandFunction));
}
}
else
{
// the rule syntax is doing the assignment, add the token item to the evaluation stack
eval.Push(item);
}
#endregion
}
else if (item.TokenType == Parser.TokenType.Token_Operator)
{
#region Token_Operator
// pop 2 items off the stack and perform the operation
// push the result back onto the evaluation stack
Parser.TokenItem rightOperand = null;
Parser.TokenItem leftOperand = null;
try
{
if (eval.Count > 0) rightOperand = eval.Pop();
if (eval.Count > 0) leftOperand = eval.Pop();
}
catch (Exception err)
{
ErrorMsg = "Error in Evaluator.Evaluate() while popping 2 tokens for an operator: " + err.Message;
return false;
}
// double check that we got the tokens before we evaluate
if (rightOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The right operand token is null: There may be an issue with the rule syntax.";
return false;
}
if (leftOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The left operand token is null: There may be an issue with the rule syntax.";
return false;
}
// process the operator
try
{
Parser.TokenItem result = null;
if (EvaluateTokens(leftOperand, rightOperand, item, out result, out ErrorMsg) == false)
return false;
else
{
// double check that we got a result
if (result == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The result of an operator is null: There may be an issue with the rule syntax.";
return false;
}
else
{
eval.Push(result);
}
}
}
catch (Exception err)
{
ErrorMsg = "Failed to evaluate the rule expression: The result of an operator threw an error: " + err.Message;
return false;
}
#endregion
}
else if (item.TokenType == Parser.TokenType.Token_Operand_Function_Stop)
{
#region Token_Operand_Function_Stop
// find the start of the function by popping off items
// evaluate the function and push the result back onto the evaluation stack
// start popping items from the evaluation stack
// until we get the start of the of the operand function
int evalCount = eval.Count;
Parser.TokenItems parameters = new Parser.TokenItems(token);
try
{
for (int j = 0; j < evalCount; j++)
{
Parser.TokenItem opItem = eval.Pop();
if (opItem.TokenType == Parser.TokenType.Token_Operand_Function_Start)
{
// we found the start of the operand function; let's evaluate it
Parser.TokenItem result = null;
if (EvaluateOperandFunction(opItem, parameters, out result, out ErrorMsg) == false)
return false;
else
{
// make sure we got a result
if (result == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The result of an operand function is null: There may be an issue with the rule syntax.";
return false;
}
else
eval.Push(result);
}
break;
}
else if (opItem.TokenType != Parser.TokenType.Token_Operand_Function_Delimiter)
{
// we have a parameter to the operand function
parameters.AddToFront(opItem);
}
}
}
catch (Exception err)
{
ErrorMsg = "Failed to evaluate the rule expression: The evaluation of an operand function threw an error: " + err.Message;
return false;
}
#endregion
}
else if (item.TokenType == Parser.TokenType.Token_Assignemt_Start)
{
#region Token_Assignment_Start
// assign the value to the variable
// pop 2 items off the stack - save the value into the variable
Parser.TokenItem rightOperand = null;
Parser.TokenItem leftOperand = null;
try
{
if (eval.Count > 0) rightOperand = eval.Pop();
if (eval.Count > 0) leftOperand = eval.Pop();
}
catch (Exception err)
{
ErrorMsg = "Error in Evaluator.Evaluate() while popping 2 tokens for an operator: " + err.Message;
return false;
}
// double check that we got the tokens before we evaluate
if (rightOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The right operand token is null: There may be an issue with the rule syntax.";
return false;
}
if (leftOperand == null)
{
ErrorMsg = "Failed to evaluate the rule expression: The left operand token is null: There may be an issue with the rule syntax.";
return false;
}
// look for the variable and assign the value to it
if (token.Variables.VariableExists(leftOperand.TokenName) == true)
{
// the variable exists, push it on the stack
token.Variables[leftOperand.TokenName].VariableValue = rightOperand.TokenName;
}
else
{
// failed to find the variable....this is an error
ErrorMsg = "Failed to evaluate the rule expression: Failed to find the variable '" + leftOperand.TokenName + "' for the assignment.";
return false;
}
#endregion
}
else if (item.TokenType == Parser.TokenType.Token_Operand_Function_Start)
{
#region New Short Circuit Code
// we are only short circuiting the IIF[] operand function
if (item.TokenName.Trim().ToLower() != "iif[")
{
// add the token to the evaluation stack
eval.Push(item);
}
else
{
// we found the iif statement.
// see if the iff[] operand function allows for short circuiting
if (item.CanShortCircuit == false)
{
// no short circuiting, add it to the evaluation stack
eval.Push(item);
}
else
{
////////////////////////////////////////////////
// We can short circuit this iif[] statement //
////////////////////////////////////////////////
Parser.TokenItem result = item.ShortCircuit.Evaluate(out ErrorMsg);
if (result == null)
{
// there was an error doing the short circuit
return false;
}
else
{
// we successfully did the short circuit
eval.Push(result);
// increment the index so we skip the ] which should be the next token
index++;
}
}
}
#endregion
}
else
{
// push the item on the evaluation stack
eval.Push(item);
}
}
if (eval.Count == 1)
{
// just 1 item on the stack; should be our answer
try
{
Parser.TokenItem final = eval.Pop();
sValue = final.TokenName;
// set the results in the token
token.LastEvaluationResult = sValue;
}
catch (Exception err)
{
ErrorMsg = "Failed to evaluate the rule expression after all the tokens have been considered: " + err.Message;
return false;
}
}
else if (eval.Count == 0)
{
// there is no result in the evaluation stack because it my have been assigned
// do nothing here
}
else
{
ErrorMsg = "Invalid Rule Syntax";
return false;
}
// stop the timer
evalTime.Stop();
tokenEvalTime = evalTime.Elapsed.TotalMilliseconds;
token.LastEvaluationTime = tokenEvalTime; // set this evaluation time in the token object.
return true;
}