Struct datafusion_physical_expr::utils::ExprTreeNode

pub struct ExprTreeNode<T> { /* private fields */ }

Implementations

impl<T> ExprTreeNode<T>

pub fn new(expr: Arc<dyn PhysicalExpr>) -> Self

pub fn expression(&self) -> &Arc<dyn PhysicalExpr>

pub fn children(&self) -> Vec<ExprTreeNode<T>>

Trait Implementations

impl<T: Clone> Clone for ExprTreeNode<T>

fn clone(&self) -> ExprTreeNode<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for ExprTreeNode<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Clone> TreeNode for ExprTreeNode<T>

fn apply_children<F>(&self, op: &mut F) -> Result<VisitRecursion>where F: FnMut(&Self) -> Result<VisitRecursion>,

Apply the closure F to the node’s children

fn map_children<F>(self, transform: F) -> Result<Self>where F: FnMut(Self) -> Result<Self>,

Apply transform F to the node’s children, the transform F might have a direction(Preorder or Postorder)

fn apply<F>(&self, op: &mut F) -> Result<VisitRecursion, DataFusionError>where F: FnMut(&Self) -> Result<VisitRecursion, DataFusionError>,

Use preorder to iterate the node on the tree so that we can stop fast for some cases.

fn visit<V>(&self, visitor: &mut V) -> Result<VisitRecursion, DataFusionError>where V: TreeNodeVisitor<N = Self>,

Visit the tree node using the given TreeNodeVisitor It performs a depth first walk of an node and its children.

fn transform<F>(self, op: &F) -> Result<Self, DataFusionError>where F: Fn(Self) -> Result<Transformed<Self>, DataFusionError>,

Convenience utils for writing optimizers rule: recursively apply the given op to the node tree. When op does not apply to a given node, it is left unchanged. The default tree traversal direction is transform_up(Postorder Traversal).

fn transform_down<F>(self, op: &F) -> Result<Self, DataFusionError>where F: Fn(Self) -> Result<Transformed<Self>, DataFusionError>,

Convenience utils for writing optimizers rule: recursively apply the given ‘op’ to the node and all of its children(Preorder Traversal). When the op does not apply to a given node, it is left unchanged.

fn transform_up<F>(self, op: &F) -> Result<Self, DataFusionError>where F: Fn(Self) -> Result<Transformed<Self>, DataFusionError>,

Convenience utils for writing optimizers rule: recursively apply the given ‘op’ first to all of its children and then itself(Postorder Traversal). When the op does not apply to a given node, it is left unchanged.

fn rewrite<R>(self, rewriter: &mut R) -> Result<Self, DataFusionError>where R: TreeNodeRewriter<N = Self>,

Transform the tree node using the given TreeNodeRewriter It performs a depth first walk of an node and its children.