public override void TryWhere(Operator op, T value, ShortSet result, ExecutionDetails details)
{
RangeToScan range = new RangeToScan();
bool rangeOk = true;
// For StartsWith, for ByteBlocks only, implement using IsPrefixOf
if (op == Operator.StartsWith)
{
if (value is ByteBlock)
{
IComparable <T> prefixComparer = (IComparable <T>)((ByteBlock)(object)value).GetExtendedIComparable(ByteBlock.Comparison.IsPrefixOf); // trust me C#... I'm a professional...
int first = FindFirstWhere(prefixComparer);
int last = FindLastWhere(prefixComparer);
if (!RangeToScan.TryBuild(Operator.Equals, first, last, this.Column.Count, ref range))
{
rangeOk = false;
if (details != null)
{
details.AddError(ExecutionDetails.ColumnDoesNotSupportOperator, op, this.Name);
}
}
}
else
{
rangeOk = false;
if (details != null)
{
details.AddError(ExecutionDetails.ColumnDoesNotSupportOperator, op, this.Name);
}
}
}
else
{
int first = FindFirstWhere(value);
int last = FindLastWhere(value);
// Determine the range to scan to compute the result
if (!RangeToScan.TryBuild(op, first, last, this.Column.Count, ref range))
{
rangeOk = false;
if (details != null)
{
details.AddError(ExecutionDetails.ColumnDoesNotSupportOperator, op, this.Name);
}
}
}
// Build the result set and return it
if (rangeOk == true)
{
range.AddMatches(this.SortedIDs, result);
}
}
private static string AddMatches(RangeToScan range, ushort[] sortedIDs, ushort[] previousValues)
{
ShortSet resultSet = new ShortSet((ushort)range.Count);
// If previous values are specified, add them
if (previousValues != null)
{
for (int i = 0; i < previousValues.Length; ++i)
{
resultSet.Add(previousValues[i]);
}
}
// Add matches for the range
range.AddMatches(sortedIDs, resultSet);
// Return the result as a string
return(String.Join(", ", resultSet.Values));
}