Class AstUtils

java.lang.Object

io.trino.sql.util.AstUtils

public final class AstUtils
extends Object

Method Summary

Modifier and Type	Method	Description
static List<Expression>	extractConjuncts(Expression expression)
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 Details

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.

extractConjuncts

public static List<Expression> extractConjuncts(Expression expression)