/// <summary>
/// Replaces a given node by another one.
/// All incident edges and variables are transferred to the new node.
/// The attributes are not touched.
/// This function is used for retyping.
/// </summary>
/// <param name="oldNode">The node to be replaced.</param>
/// <param name="newNode">The replacement for the node.</param>
public void ReplaceNode(LGSPNode oldNode, LGSPNode newNode)
{
if(oldNode.lgspType != newNode.lgspType)
{
if(!oldNode.Valid)
throw new Exception("Fatal failure at retyping: The old node is not a member of the graph (any more).");
oldNode.lgspTypePrev.lgspTypeNext = oldNode.lgspTypeNext;
oldNode.lgspTypeNext.lgspTypePrev = oldNode.lgspTypePrev;
nodesByTypeCounts[oldNode.lgspType.TypeID]--;
AddNodeWithoutEvents(newNode, newNode.lgspType.TypeID);
}
else
{
newNode.lgspTypeNext = oldNode.lgspTypeNext;
newNode.lgspTypePrev = oldNode.lgspTypePrev;
oldNode.lgspTypeNext.lgspTypePrev = newNode;
oldNode.lgspTypePrev.lgspTypeNext = newNode;
}
oldNode.lgspTypeNext = newNode; // indicate replacement (checked in rewrite for hom nodes)
oldNode.lgspTypePrev = null; // indicate node is node valid anymore
// Reassign all outgoing edges
LGSPEdge outHead = oldNode.lgspOuthead;
if(outHead != null)
{
LGSPEdge outCur = outHead;
do
{
outCur.lgspSource = newNode;
outCur = outCur.lgspOutNext;
}
while(outCur != outHead);
}
newNode.lgspOuthead = outHead;
// Reassign all incoming edges
LGSPEdge inHead = oldNode.lgspInhead;
if(inHead != null)
{
LGSPEdge inCur = inHead;
do
{
inCur.lgspTarget = newNode;
inCur = inCur.lgspInNext;
}
while(inCur != inHead);
}
newNode.lgspInhead = inHead;
++changesCounter;
if(reuseOptimization)
oldNode.Recycle();
#if CHECK_RINGLISTS
CheckTypeRinglistBroken(nodesByTypeHeads[newNode.lgspType.TypeID]);
CheckInOutRinglistsBroken(newNode);
#endif
}
internal void RemoveNodeWithoutEvents(LGSPNode node, int typeid)
{
node.lgspTypePrev.lgspTypeNext = node.lgspTypeNext;
node.lgspTypeNext.lgspTypePrev = node.lgspTypePrev;
node.lgspTypeNext = null;
node.lgspTypePrev = null;
--nodesByTypeCounts[typeid];
++changesCounter;
if(reuseOptimization)
node.Recycle();
#if CHECK_RINGLISTS
CheckTypeRinglistBroken(nodesByTypeHeads[typeid]);
#endif
}
