private Node VisitNestOp(Node n)
{
var op = n.Op as NestBaseOp;
var ssnOp = op as SingleStreamNestOp;
Debug.Assert(op != null);
// Visit the Node's children and map their Vars
var newChildren = ProcessChildren(n);
Var newDiscriminator = null;
if (ssnOp != null)
{
newDiscriminator = GetMappedVar(ssnOp.Discriminator);
}
var newCollectionInfoList = new List <CollectionInfo>();
foreach (var ci in op.CollectionInfo)
{
var newColumnMap = Copy(ci.ColumnMap);
Var newCollectionVar = m_destCmd.CreateComputedVar(ci.CollectionVar.Type);
SetMappedVar(ci.CollectionVar, newCollectionVar);
var newFlattendElementVars = Copy(ci.FlattenedElementVars);
var newKeys = Copy(ci.Keys);
var newSortKeys = Copy(ci.SortKeys);
var newCollectionInfo = Command.CreateCollectionInfo(
newCollectionVar, newColumnMap, newFlattendElementVars, newKeys, newSortKeys, ci.DiscriminatorValue);
newCollectionInfoList.Add(newCollectionInfo);
}
var newOutputs = Copy(op.Outputs);
NestBaseOp newOp = null;
var newPrefixSortKeys = Copy(op.PrefixSortKeys);
if (ssnOp != null)
{
var newKeys = Copy(ssnOp.Keys);
// Copy the SortOp's SortKeys
var newPostfixSortKeys = Copy(ssnOp.PostfixSortKeys);
newOp = m_destCmd.CreateSingleStreamNestOp(
newKeys, newPrefixSortKeys, newPostfixSortKeys, newOutputs, newCollectionInfoList, newDiscriminator);
}
else
{
newOp = m_destCmd.CreateMultiStreamNestOp(newPrefixSortKeys, newOutputs, newCollectionInfoList);
}
return(m_destCmd.CreateNode(newOp, newChildren));
}
