AstUtils (trino-parser 358 API)

java.lang.Object
- io.trino.sql.util.AstUtils

public final class AstUtils
extends Object

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static Stream<Node>`	`preOrder(Node node)`
`static boolean`	`treeEqual(Node left, Node right, BiFunction<Node,Node,Boolean> subtreeComparator)`	Compares two AST trees recursively by applying the provided comparator to each pair of nodes.
`static int`	`treeHash(Node node, Function<Node,OptionalInt> subtreeHasher)`	Computes a hash of the given AST by applying the provided subtree hasher at each level.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - preOrder
```
public static Stream<Node> preOrder(Node node)
```
  - treeEqual
```
public static boolean treeEqual(Node left,
                                Node right,
                                BiFunction<Node,Node,Boolean> subtreeComparator)
```
    Compares two AST trees recursively by applying the provided comparator to each pair of nodes.
    
    The comparator can perform a hybrid shallow/deep comparison. If it returns true or false, the nodes and any subtrees are considered equal or different, respectively. If it returns null, the nodes are considered shallowly-equal and their children will be compared recursively.
  - treeHash
```
public static int treeHash(Node node,
                           Function<Node,OptionalInt> subtreeHasher)
```
    Computes a hash of the given AST by applying the provided subtree hasher at each level.
    
    If the hasher returns a non-empty OptionalInt, the value is treated as the hash for the subtree at that node. Otherwise, the hashes of its children are computed and combined.