Module datafusion_common::tree_node

This module provides common traits for visiting or rewriting tree data structures easily.

Enums

• RewriteRecursion
  Controls how the TreeNode recursion should proceed for TreeNode::rewrite.
• Transformed
• VisitRecursion
  Controls how the TreeNode recursion should proceed for TreeNode::visit.

Traits

• ConcreteTreeNode
  Instead of implementing TreeNode, it’s recommended to implement a ConcreteTreeNode for trees that contain nodes with payloads. This approach ensures safe execution of algorithms involving payloads, by enforcing rules for detaching and reattaching child nodes.
• DynTreeNode
  Helper trait for implementing TreeNode that have children stored as Arc’s
• TreeNode
  Defines a visitable and rewriteable a tree node. This trait is implemented for plans (ExecutionPlan and LogicalPlan) as well as expression trees (PhysicalExpr, Expr) in DataFusion
• TreeNodeRewriter
  Trait for potentially recursively transform an TreeNode node tree. When passed to TreeNode::rewrite, TreeNodeRewriter::mutate is invoked recursively on all nodes of a tree.
• TreeNodeVisitor
  Implements the visitor pattern for recursively walking TreeNodes.