org.apache.calcite.runtime

Class Enumerables

java.lang.Object

org.apache.calcite.runtime.Enumerables

public class Enumerables
extends Object

Utilities for processing Enumerable collections.

This class is a place to put things not yet added to linq4j. Methods are subject to removal without notice.

Method Summary

Methods

Modifier and Type	Method and Description
static <TSource,TInner,TKey extends Comparable<TKey>,TResult> Enumerable<TResult>	mergeJoin(Enumerable<TSource> outer, Enumerable<TInner> inner, Function1<TSource,TKey> outerKeySelector, Function1<TInner,TKey> innerKeySelector, Function2<TSource,TInner,TResult> resultSelector, boolean generateNullsOnLeft, boolean generateNullsOnRight) Joins two inputs that are sorted on the key.
static <TSource,TInner,TKey> Enumerable<TSource>	semiJoin(Enumerable<TSource> outer, Enumerable<TInner> inner, Function1<TSource,TKey> outerKeySelector, Function1<TInner,TKey> innerKeySelector) Returns elements of outer for which there is a member of inner with a matching key.
static <TSource,TInner,TKey> Enumerable<TSource>	semiJoin(Enumerable<TSource> outer, Enumerable<TInner> inner, Function1<TSource,TKey> outerKeySelector, Function1<TInner,TKey> innerKeySelector, EqualityComparer<TKey> comparer) Returns elements of outer for which there is a member of inner with a matching key.
static <E> Enumerable<E>	slice0(Enumerable<E[]> enumerable) Converts an enumerable over singleton arrays into the enumerable of their first elements.
static <TSource,TInner,TResult> Enumerable<TResult>	thetaJoin(Enumerable<TSource> outer, Enumerable<TInner> inner, Predicate2<TSource,TInner> predicate, Function2<TSource,TInner,TResult> resultSelector, boolean generateNullsOnLeft, boolean generateNullsOnRight) Correlates the elements of two sequences based on a predicate.
static Enumerable<Row>	toRow(Enumerable<Object[]> enumerator) Converts an Enumerable over object arrays into an Enumerable over Row objects.
static <TSource> Enumerable<TSource>	where(Enumerable<TSource> source, Predicate1<TSource> predicate) Filters a sequence of values based on a predicate.

Methods inherited from class java.lang.Object

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

Method Detail

slice0

public static <E> Enumerable<E> slice0(Enumerable<E[]> enumerable)

Converts an enumerable over singleton arrays into the enumerable of their first elements.

semiJoin

public static <TSource,TInner,TKey> Enumerable<TSource> semiJoin(Enumerable<TSource> outer,
                                                 Enumerable<TInner> inner,
                                                 Function1<TSource,TKey> outerKeySelector,
                                                 Function1<TInner,TKey> innerKeySelector)

Returns elements of outer for which there is a member of inner with a matching key.

semiJoin

public static <TSource,TInner,TKey> Enumerable<TSource> semiJoin(Enumerable<TSource> outer,
                                                 Enumerable<TInner> inner,
                                                 Function1<TSource,TKey> outerKeySelector,
                                                 Function1<TInner,TKey> innerKeySelector,
                                                 EqualityComparer<TKey> comparer)

Returns elements of outer for which there is a member of inner with a matching key. A specified EqualityComparer<TSource> is used to compare keys.

thetaJoin

public static <TSource,TInner,TResult> Enumerable<TResult> thetaJoin(Enumerable<TSource> outer,
                                                     Enumerable<TInner> inner,
                                                     Predicate2<TSource,TInner> predicate,
                                                     Function2<TSource,TInner,TResult> resultSelector,
                                                     boolean generateNullsOnLeft,
                                                     boolean generateNullsOnRight)

Correlates the elements of two sequences based on a predicate.

where

public static <TSource> Enumerable<TSource> where(Enumerable<TSource> source,
                                  Predicate1<TSource> predicate)

Filters a sequence of values based on a predicate.

toRow

public static Enumerable<Row> toRow(Enumerable<Object[]> enumerator)

Converts an Enumerable over object arrays into an Enumerable over Row objects.

mergeJoin

public static <TSource,TInner,TKey extends Comparable<TKey>,TResult> Enumerable<TResult> mergeJoin(Enumerable<TSource> outer,
                                                                                   Enumerable<TInner> inner,
                                                                                   Function1<TSource,TKey> outerKeySelector,
                                                                                   Function1<TInner,TKey> innerKeySelector,
                                                                                   Function2<TSource,TInner,TResult> resultSelector,
                                                                                   boolean generateNullsOnLeft,
                                                                                   boolean generateNullsOnRight)

Joins two inputs that are sorted on the key.