//-------------------------------------------------------------------------
//
// cloneTree Make a copy of the subtree rooted at this node.
// Discard any variable references encountered along the way,
// and replace with copies of the variable's definitions.
// Used to replicate the expression underneath variable
// references in preparation for generating the DFA tables.
//
//-------------------------------------------------------------------------
internal virtual RBBINode CloneTree()
{
RBBINode n;
if (fType == RBBINode.varRef)
{
// If the current node is a variable reference, skip over it
// and clone the definition of the variable instead.
n = fLeftChild.CloneTree();
}
else if (fType == RBBINode.uset)
{
n = this;
}
else
{
n = new RBBINode(this);
if (fLeftChild != null)
{
n.fLeftChild = fLeftChild.CloneTree();
n.fLeftChild.fParent = n;
}
if (fRightChild != null)
{
n.fRightChild = fRightChild.CloneTree();
n.fRightChild.fParent = n;
}
}
return(n);
}
//-------------------------------------------------------------------------
//
// flattenSets Walk the parse tree, replacing any nodes of type setRef
// with a copy of the expression tree for the set. A set's
// equivalent expression tree is precomputed and saved as
// the left child of the uset node.
//
//-------------------------------------------------------------------------
internal virtual void FlattenSets()
{
Assert.Assrt(fType != setRef);
if (fLeftChild != null)
{
if (fLeftChild.fType == setRef)
{
RBBINode setRefNode = fLeftChild;
RBBINode usetNode = setRefNode.fLeftChild;
RBBINode replTree = usetNode.fLeftChild;
fLeftChild = replTree.CloneTree();
fLeftChild.fParent = this;
}
else
{
fLeftChild.FlattenSets();
}
}
if (fRightChild != null)
{
if (fRightChild.fType == setRef)
{
RBBINode setRefNode = fRightChild;
RBBINode usetNode = setRefNode.fLeftChild;
RBBINode replTree = usetNode.fLeftChild;
fRightChild = replTree.CloneTree();
fRightChild.fParent = this;
// delete setRefNode;
}
else
{
fRightChild.FlattenSets();
}
}
}
