/// <summary>
/// Common copy path for all SetOps
/// </summary>
/// <param name="op">The SetOp to Copy (must be one of ExceptOp, IntersectOp, UnionAllOp)</param>
/// <param name="n">The Node that references the Op</param>
/// <returns>A copy of the original Node that references a copy of the original Op</returns>
private Node CopySetOp(SetOp op, Node n)
{
// Visit the Node's children and map their Vars
List <Node> children = ProcessChildren(n);
VarMap leftMap = new VarMap();
VarMap rightMap = new VarMap();
foreach (KeyValuePair <Var, Var> kv in op.VarMap[0])
{
// Create a new output Var that is a copy of the original output Var
Var outputVar = m_destCmd.CreateSetOpVar(kv.Key.Type);
// Add a mapping for the new output var we've just created
SetMappedVar(kv.Key, outputVar);
// Add this output var's entries to the new VarMaps
leftMap.Add(outputVar, GetMappedVar(kv.Value));
rightMap.Add(outputVar, GetMappedVar((op.VarMap[1])[kv.Key]));
}
SetOp newSetOp = null;
switch (op.OpType)
{
case OpType.UnionAll:
{
Var branchDiscriminator = ((UnionAllOp)op).BranchDiscriminator;
if (null != branchDiscriminator)
{
branchDiscriminator = GetMappedVar(branchDiscriminator);
}
newSetOp = m_destCmd.CreateUnionAllOp(leftMap, rightMap, branchDiscriminator);
}
break;
case OpType.Intersect:
{
newSetOp = m_destCmd.CreateIntersectOp(leftMap, rightMap);
}
break;
case OpType.Except:
{
newSetOp = m_destCmd.CreateExceptOp(leftMap, rightMap);
}
break;
default:
{
Debug.Assert(false, "Unexpected SetOpType");
}
break;
}
return(m_destCmd.CreateNode(newSetOp, children));
}
/// <summary>
/// Set the "cloned" var for a given Var
/// WARNING: If a mapping already exists, an exception is raised
/// </summary>
/// <param name="v">The original Var</param>
/// <param name="mappedVar">The cloned Var</param>
private void SetMappedVar(Var v, Var mappedVar)
{
m_varMap.Add(v, mappedVar);
}
