public void commit(Stack <ExpressionPart> values)
{
EOperand left = null;
EOperand right = null;
if (this.priority != 6)
{
right = (EOperand)values.Pop();
}
left = (EOperand)values.Pop();
try
{
switch (this.priority)
{
case 6:
values.Push(new EOperand((!left.value).ToString()));
break;
case 5:
values.Push(new EOperand((left.value & right.value).ToString()));
break;
case 4:
values.Push(new EOperand((left.value | right.value).ToString()));
break;
case 3:
values.Push(new EOperand(((!left.value) | right.value).ToString()));
break;
case 2:
values.Push(new EOperand((left.value == right.value).ToString()));
break;
}
}
catch (InvalidOperationException ex) {
throw new InvalidOperationException("Some of operands doesn't have it's value(value property == null)", ex);
}
}
public LogicExpression(String strExpression)
{
//Parsing expression from string to set of ExpressionPart objects
body = new Queue <ExpressionPart>();
String delimiters = LogicSymbols.OR + LogicSymbols.AND + LogicSymbols.IMP + LogicSymbols.NOT;
String[] parts = Regex.Split(strExpression, @"(?=[" + delimiters + ")(]|)|(?<=[" + delimiters + ")(])");
body.Enqueue(new ESeparateSymbol(true));
ExpressionPart x;
foreach (String i in parts)
{
if (EBrackets.isSuitablePart(i))
{
body.Enqueue(new EBrackets(i));
}
else if (EOperation.isSuitablePart(i))
{
x = new EOperation(i);
body.Enqueue(x);
}
else if (EOperand.isSuitablePart(i))
{
x = new EOperand(i);
if (operands.Contains(x) && !((EOperand)x).isConstant)
{
x = operands.First <EOperand>(p => p.Equals(x));
}
if (!operands.Contains(x) && !((EOperand)x).isConstant)
{
operands.Add((EOperand)x);
}
body.Enqueue((EOperand)x);
}
}
body.Enqueue(new ESeparateSymbol(false));
this.operands = this.operands.OrderBy <EOperand, String>(p => p.text).ToList <EOperand>();
}
//Method finds solution of logic expression using RPN
public EOperand calculate()
{
if (!isRPNcreated)
{
throw new InvalidOperationException("Reversed polish notation hasn't been created yet");
}
Stack <ExpressionPart> calcField = new Stack <ExpressionPart>();
Stack <ExpressionPart> polishNotation = new Stack <ExpressionPart>(California);
while (polishNotation.Count > 0)
{
//Selecting operands
while ((polishNotation.Count > 0) && (polishNotation.Peek() is EOperand))
{
calcField.Push(polishNotation.Pop());
}
//Looking for operators and computing
while ((polishNotation.Count > 0) && (polishNotation.Peek() is EOperation))
{
EOperation op = null;
try
{
op = (EOperation)polishNotation.Pop();
op.commit(calcField);
}
catch (InvalidOperationException) {
throw new FormatException("Math expression isn't correct");
}
}
}
this.isCalculated = true;
this.solution = (EOperand)calcField.Pop();
return(this.solution);
}
