org.apache.hadoop.hive.ql.lib
Class Utils

java.lang.Object
  org.apache.hadoop.hive.ql.lib.Utils

public class Utils
extends Object

Contains common utility functions to manipulate nodes, walkers etc.

Constructor Summary

Utils()

Method Summary

static <T> T	findNode(Stack<Node> stack, Class<T> target) Find the first node of a type from ancestor stack, starting from parents.
static Node	getNthAncestor(Stack<Node> st, int n) Gets the nth ancestor (the parent being the 1st ancestor) in the traversal path.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Utils

public Utils()

Method Detail

getNthAncestor

public static Node getNthAncestor(Stack<Node> st,
                                  int n)

Gets the nth ancestor (the parent being the 1st ancestor) in the traversal path. n=0 returns the currently visited node.

Parameters:

st - The stack that encodes the traversal path.

n - The value of n (n=0 is the currently visited node).

Returns:

Node The Nth ancestor in the path with respect to the current node.

findNode

public static <T> T findNode(Stack<Node> stack,
                             Class<T> target)

Find the first node of a type from ancestor stack, starting from parents. Returns null if not found.