SplayNode SplayTreeNext(SplayTree tree, SplayNode oldNode, void *oldKey) {
Bool b;
SplayNode node;
AVERT(SplayTree, tree);
AVERT(SplayNode, oldNode);
/* Make old node the root. Probably already is. */
b = SplaySplay(&node, tree, oldKey, tree->compare);
AVER(b);
AVER(node == oldNode);
return SplayTreeSuccessor(tree, oldKey);
}
Tree SplayTreeNext(SplayTree splay, TreeKey oldKey) {
AVERT(SplayTree, splay);
if (SplayTreeIsEmpty(splay))
return TreeEMPTY;
/* Make old node the root. Probably already is. We don't mind if the
node has been deleted, or replaced by a node with the same key. */
switch (SplaySplay(splay, oldKey, splay->compare)) {
default:
NOTREACHED;
/* defensive fall-through */
case CompareLESS:
return SplayTreeRoot(splay);
case CompareGREATER:
case CompareEQUAL:
return SplayTreeSuccessor(splay);
}
}
Res SplayTreeNeighbours(SplayNode *leftReturn, SplayNode *rightReturn,
SplayTree tree, void *key) {
SplayNode neighbour;
AVERT(SplayTree, tree);
AVER(leftReturn != NULL);
AVER(rightReturn != NULL);
if (SplaySplay(&neighbour, tree, key, tree->compare)) {
return ResFAIL;
} else if (neighbour == NULL) {
*leftReturn = *rightReturn = NULL;
} else {
switch(SplayCompare(tree, key, neighbour)) {
case CompareLESS: {
*rightReturn = neighbour;
*leftReturn = SplayTreePredecessor(tree, key);
}
break;
case CompareGREATER: {
*leftReturn = neighbour;
*rightReturn = SplayTreeSuccessor(tree, key);
}
break;
case CompareEQUAL:
default: {
NOTREACHED;
}
break;
}
}
return ResOK;
}
