/// <summary>
/// Evaluates a list expression
/// </summary>
/// <returns></returns>
private Expression EvaluateListExpression()
{
Expression retVal = null;
string listOp = LookAhead(ListOperators.ListOperatorExpression.LIST_OPERATORS);
if (listOp != null)
{
Match(listOp);
Expression listExpression = Expression(0);
Expression condition = null;
if (LookAhead("|"))
{
Match("|");
condition = Expression(0);
}
if (listOp.CompareTo(ListOperators.MapExpression.OPERATOR) == 0 ||
listOp.CompareTo(ListOperators.ReduceExpression.OPERATOR) == 0 ||
listOp.CompareTo(ListOperators.SumExpression.OPERATOR) == 0)
{
Match("USING");
Expression iteratorExpression = Expression(0);
if (iteratorExpression != null)
{
if (ListOperators.MapExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.MapExpression(Root, listExpression, condition, iteratorExpression);
}
else if (ListOperators.SumExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.SumExpression(Root, listExpression, condition, iteratorExpression);
}
else if (ListOperators.ReduceExpression.OPERATOR.CompareTo(listOp) == 0)
{
Match("INITIAL_VALUE");
Expression initialValue = Expression(0);
if (initialValue != null)
{
retVal = new ListOperators.ReduceExpression(Root, listExpression, condition, iteratorExpression, initialValue);
}
else
{
throw new ParseErrorException("REDUCE requires an initial value");
}
}
}
else
{
throw new ParseErrorException("Function designator expected");
}
}
else
{
// Create the right class for this list operation
if (ListOperators.ThereIsExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.ThereIsExpression(Root, listExpression, condition);
}
else if (ListOperators.ForAllExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.ForAllExpression(Root, listExpression, condition);
}
else if (ListOperators.FirstExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.FirstExpression(Root, listExpression, condition);
}
else if (ListOperators.LastExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.LastExpression(Root, listExpression, condition);
}
else if (ListOperators.CountExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.CountExpression(Root, listExpression, condition);
}
}
}
return(retVal);
}
/// <summary>
/// Evaluates a list expression
/// </summary>
/// <returns></returns>
private Expression EvaluateListExpression()
{
Expression retVal = null;
SkipWhiteSpaces();
int start = Index;
string listOp = LookAhead(ListOperatorExpression.ListOperators);
if (listOp != null)
{
Match(listOp);
if (MapExpression.Operator.Equals(listOp)
|| ReduceExpression.Operator.Equals(listOp)
|| SumExpression.Operator.Equals(listOp) )
{
Expression listExpression = Expression(0);
if (listExpression != null)
{
Expression condition = null;
if (LookAhead("|"))
{
Match("|");
condition = Expression(0);
}
Match("USING");
string iteratorIdentifier = Identifier();
Match("IN");
Expression iteratorExpression = Expression(0);
if (iteratorExpression != null)
{
if (MapExpression.Operator.Equals(listOp))
{
retVal = new MapExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
iteratorExpression, start, Index);
}
else if (SumExpression.Operator.Equals(listOp))
{
retVal = new SumExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
iteratorExpression, start, Index);
}
else if (ReduceExpression.Operator.Equals(listOp))
{
Match("INITIAL_VALUE");
Expression initialValue = Expression(0);
if (initialValue != null)
{
retVal = new ReduceExpression(Root, RootLog, listExpression, iteratorIdentifier,
condition, iteratorExpression, initialValue, start, Index);
}
else
{
throw new ParseErrorException("REDUCE requires an initial value", Index, Buffer);
}
}
}
else
{
throw new ParseErrorException("Function designator expected", Index, Buffer);
}
}
}
else
{
string iteratorIdentifier = Identifier();
Match("IN");
Expression listExpression = Expression(6);
if (listExpression != null)
{
Expression condition = null;
if (LookAhead("|"))
{
Match("|");
condition = Expression(0);
}
// Create the right class for this list operation
if (ThereIsExpression.Operator.Equals(listOp))
{
retVal = new ThereIsExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
start, Index);
}
else if (ForAllExpression.Operator.Equals(listOp))
{
retVal = new ForAllExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
start, Index);
}
else if (FirstExpression.Operator.Equals(listOp))
{
retVal = new FirstExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
start, Index);
}
else if (LastExpression.Operator.Equals(listOp))
{
retVal = new LastExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
start, Index);
}
else if (CountExpression.Operator.Equals(listOp))
{
retVal = new CountExpression(Root, RootLog, listExpression, iteratorIdentifier, condition,
start, Index);
}
}
}
}
return retVal;
}
/// <summary>
/// Visits a SUM expression
/// </summary>
/// <param name="sumExpression"></param>
protected virtual void VisitSumExpression(SumExpression sumExpression)
{
if (sumExpression != null)
{
VisitConditionBasedListExpression(sumExpression);
VisitExpression(sumExpression.IteratorExpression);
}
}
/// <summary>
/// Evaluates a list expression
/// </summary>
/// <returns></returns>
private Expression EvaluateListExpression()
{
Expression retVal = null;
string listOp = LookAhead(ListOperators.ListOperatorExpression.LIST_OPERATORS);
if (listOp != null)
{
Match(listOp);
Expression listExpression = Expression(0);
Expression condition = null;
if (LookAhead("|"))
{
Match("|");
condition = Expression(0);
}
if (listOp.CompareTo(ListOperators.MapExpression.OPERATOR) == 0
|| listOp.CompareTo(ListOperators.ReduceExpression.OPERATOR) == 0
|| listOp.CompareTo(ListOperators.SumExpression.OPERATOR) == 0)
{
Match("USING");
Expression iteratorExpression = Expression(0);
if (iteratorExpression != null)
{
if (ListOperators.MapExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.MapExpression(Root, listExpression, condition, iteratorExpression);
}
else if (ListOperators.SumExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.SumExpression(Root, listExpression, condition, iteratorExpression);
}
else if (ListOperators.ReduceExpression.OPERATOR.CompareTo(listOp) == 0)
{
Match("INITIAL_VALUE");
Expression initialValue = Expression(0);
if (initialValue != null)
{
retVal = new ListOperators.ReduceExpression(Root, listExpression, condition, iteratorExpression, initialValue);
}
else
{
throw new ParseErrorException("REDUCE requires an initial value");
}
}
}
else
{
throw new ParseErrorException("Function designator expected");
}
}
else
{
// Create the right class for this list operation
if (ListOperators.ThereIsExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.ThereIsExpression(Root, listExpression, condition);
}
else if (ListOperators.ForAllExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.ForAllExpression(Root, listExpression, condition);
}
else if (ListOperators.FirstExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.FirstExpression(Root, listExpression, condition);
}
else if (ListOperators.LastExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.LastExpression(Root, listExpression, condition);
}
else if (ListOperators.CountExpression.OPERATOR.CompareTo(listOp) == 0)
{
retVal = new ListOperators.CountExpression(Root, listExpression, condition);
}
}
}
return retVal;
}