private function assertChildrenCount(TreeNode $node, $count)
{
if ($node->getChildrenNumber() !== $count) {
throw new Exception(sprintf('Node was expected to have only %s children.', $count));
}
}
/**
* Merge recursively.
* Please, see self::mergeTree() to know the context.
*
* @param \Hoa\Compiler\Llk\TreeNode $node Node that receives.
* @param \Hoa\Compiler\Llk\TreeNode $newNode Node to merge.
* @return void
*/
protected function mergeTreeRecursive(TreeNode $node, TreeNode $newNode)
{
$nNId = $newNode->getId();
if ('token' === $nNId) {
$node->appendChild($newNode);
$newNode->setParent($node);
return;
}
$children = $node->getChildren();
end($children);
$last = current($children);
if ($last->getId() !== $nNId) {
$node->appendChild($newNode);
$newNode->setParent($node);
return;
}
foreach ($newNode->getChildren() as $child) {
$this->mergeTreeRecursive($last, $child);
}
return;
}
private function leftRotateTree(TreeNode &$root)
{
// Pivot = Root.Left
$pivot = $root->getChild(1);
// Root.Right = Pivot.Left
$children = $root->getChildren();
$children[1] = $pivot->getChild(0);
// Pivot, rotation side
$root->setChildren($children);
// Pivot.Left = Root
$children = $pivot->getChildren();
$children[0] = $root;
$pivot->setChildren($children);
// Root = Pivot
$root = $pivot;
}
