internal override Opcode Eval(ProcessingContext context)
{
StackFrame topFrame = context.TopSequenceArg;
SeekableXPathNavigator node = null;
Value[] sequences = context.Sequences;
for (int i = topFrame.basePtr; i <= topFrame.endPtr; ++i)
{
// Each NodeSequence will generate a new one, but only if the source FilterSequence isn't empty
// If the source FilterSequence is empty, release it and replace it with an empty sequence
NodeSequence sourceSeq = sequences[i].Sequence;
int sourceSeqCount = sourceSeq.Count;
if (sourceSeqCount == 0)
{
context.ReplaceSequenceAt(i, NodeSequence.Empty);
context.ReleaseSequence(sourceSeq);
}
else
{
NodeSequenceItem[] items = sourceSeq.Items;
if (sourceSeq.CanReuse(context))
{
node = items[0].GetNavigator();
sourceSeq.Clear();
sourceSeq.StartNodeset();
this.criteria.Select(node, sourceSeq);
sourceSeq.StopNodeset();
}
else
{
NodeSequence newSeq = null;
for (int item = 0; item < sourceSeqCount; ++item)
{
node = items[item].GetNavigator();
Fx.Assert(null != node, "");
if (null == newSeq)
{
newSeq = context.CreateSequence();
}
newSeq.StartNodeset();
this.criteria.Select(node, newSeq);
newSeq.StopNodeset();
}
context.ReplaceSequenceAt(i, (null != newSeq) ? newSeq : NodeSequence.Empty);
context.ReleaseSequence(sourceSeq);
}
}
}
return(this.next);
}
internal override Opcode Eval(ProcessingContext context)
{
StackFrame topSequenceArg = context.TopSequenceArg;
SeekableXPathNavigator contextNode = null;
Value[] sequences = context.Sequences;
for (int i = topSequenceArg.basePtr; i <= topSequenceArg.endPtr; i++)
{
NodeSequence sequence = sequences[i].Sequence;
int count = sequence.Count;
if (count == 0)
{
context.ReplaceSequenceAt(i, NodeSequence.Empty);
context.ReleaseSequence(sequence);
}
else
{
NodeSequenceItem[] items = sequence.Items;
if (sequence.CanReuse(context))
{
contextNode = items[0].GetNavigator();
sequence.Clear();
sequence.StartNodeset();
this.criteria.Select(contextNode, sequence);
sequence.StopNodeset();
}
else
{
NodeSequence destSequence = null;
for (int j = 0; j < count; j++)
{
contextNode = items[j].GetNavigator();
if (destSequence == null)
{
destSequence = context.CreateSequence();
}
destSequence.StartNodeset();
this.criteria.Select(contextNode, destSequence);
destSequence.StopNodeset();
}
context.ReplaceSequenceAt(i, (destSequence != null) ? destSequence : NodeSequence.Empty);
context.ReleaseSequence(sequence);
}
}
}
return(base.next);
}
