org.eclipse.collections.impl.utility

Class LazyIterate

java.lang.Object

org.eclipse.collections.impl.utility.LazyIterate

public final class LazyIterate
extends Object

LazyIterate is a factory class which creates "deferred" iterables around the specified iterables. A "deferred" iterable performs some operation, such as filtering or transforming, when the result iterable is iterated over. This makes the operation very memory efficient, because you don't have to create intermediate collections during the operation.

Since:

1.0

Method Summary

Modifier and Type	Method and Description
static <T> org.eclipse.collections.api.LazyIterable<T>	adapt(Iterable<T> iterable) Creates a deferred rich iterable for the specified iterable
static <T> org.eclipse.collections.api.LazyIterable<org.eclipse.collections.api.RichIterable<T>>	chunk(Iterable<T> iterable, int size)
static <T,V> org.eclipse.collections.api.LazyIterable<V>	collect(Iterable<T> iterable, org.eclipse.collections.api.block.function.Function<? super T,? extends V> function) Creates a deferred transforming iterable for the specified iterable
static <T,V> org.eclipse.collections.api.LazyIterable<V>	collectIf(Iterable<T> iterable, org.eclipse.collections.api.block.predicate.Predicate<? super T> predicate, org.eclipse.collections.api.block.function.Function<? super T,? extends V> function) Creates a deferred filtering and transforming iterable for the specified iterable
static <T> org.eclipse.collections.api.LazyIterable<T>	concatenate(Iterable<T>... iterables) Combines iterables into a deferred composite iterable
static <T> org.eclipse.collections.api.LazyIterable<T>	distinct(Iterable<T> iterable) Creates a deferred distinct iterable for the specified iterable
static <T> org.eclipse.collections.api.LazyIterable<T>	drop(Iterable<T> iterable, int count) Creates a deferred drop iterable for the specified iterable using the specified count as the size to drop
static <T> org.eclipse.collections.api.LazyIterable<T>	empty()
static <T,V> org.eclipse.collections.api.LazyIterable<V>	flatCollect(Iterable<T> iterable, org.eclipse.collections.api.block.function.Function<? super T,? extends Iterable<V>> function) Creates a deferred flattening iterable for the specified iterable
static <T> org.eclipse.collections.api.LazyIterable<T>	reject(Iterable<T> iterable, org.eclipse.collections.api.block.predicate.Predicate<? super T> predicate) Creates a deferred negative filtering iterable for the specified iterable
static <T> org.eclipse.collections.api.LazyIterable<T>	select(Iterable<T> iterable, org.eclipse.collections.api.block.predicate.Predicate<? super T> predicate) Creates a deferred filtering iterable for the specified iterable
static <T> org.eclipse.collections.api.LazyIterable<T>	selectInstancesOf(Iterable<?> iterable, Class<T> clazz)
static <T> org.eclipse.collections.api.LazyIterable<T>	take(Iterable<T> iterable, int count) Creates a deferred take iterable for the specified iterable using the specified count as the limit
static <T> org.eclipse.collections.api.LazyIterable<T>	tap(Iterable<T> iterable, org.eclipse.collections.api.block.procedure.Procedure<? super T> procedure) Creates a deferred tap iterable for the specified iterable.
static <A,B> org.eclipse.collections.api.LazyIterable<org.eclipse.collections.api.tuple.Pair<A,B>>	zip(Iterable<A> as, Iterable<B> bs)
static <T> org.eclipse.collections.api.LazyIterable<org.eclipse.collections.api.tuple.Pair<T,Integer>>	zipWithIndex(Iterable<T> iterable)

Methods inherited from class java.lang.Object

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

Method Detail

adapt

public static <T> org.eclipse.collections.api.LazyIterable<T> adapt(Iterable<T> iterable)

Creates a deferred rich iterable for the specified iterable

select

public static <T> org.eclipse.collections.api.LazyIterable<T> select(Iterable<T> iterable,
                                                                     org.eclipse.collections.api.block.predicate.Predicate<? super T> predicate)

Creates a deferred filtering iterable for the specified iterable

reject

public static <T> org.eclipse.collections.api.LazyIterable<T> reject(Iterable<T> iterable,
                                                                     org.eclipse.collections.api.block.predicate.Predicate<? super T> predicate)

Creates a deferred negative filtering iterable for the specified iterable

selectInstancesOf

public static <T> org.eclipse.collections.api.LazyIterable<T> selectInstancesOf(Iterable<?> iterable,
                                                                                Class<T> clazz)

collect

public static <T,V> org.eclipse.collections.api.LazyIterable<V> collect(Iterable<T> iterable,
                                                                        org.eclipse.collections.api.block.function.Function<? super T,? extends V> function)

Creates a deferred transforming iterable for the specified iterable

flatCollect

public static <T,V> org.eclipse.collections.api.LazyIterable<V> flatCollect(Iterable<T> iterable,
                                                                            org.eclipse.collections.api.block.function.Function<? super T,? extends Iterable<V>> function)

Creates a deferred flattening iterable for the specified iterable

collectIf

public static <T,V> org.eclipse.collections.api.LazyIterable<V> collectIf(Iterable<T> iterable,
                                                                          org.eclipse.collections.api.block.predicate.Predicate<? super T> predicate,
                                                                          org.eclipse.collections.api.block.function.Function<? super T,? extends V> function)

Creates a deferred filtering and transforming iterable for the specified iterable

take

public static <T> org.eclipse.collections.api.LazyIterable<T> take(Iterable<T> iterable,
                                                                   int count)

Creates a deferred take iterable for the specified iterable using the specified count as the limit

drop

public static <T> org.eclipse.collections.api.LazyIterable<T> drop(Iterable<T> iterable,
                                                                   int count)

Creates a deferred drop iterable for the specified iterable using the specified count as the size to drop

distinct

public static <T> org.eclipse.collections.api.LazyIterable<T> distinct(Iterable<T> iterable)

Creates a deferred distinct iterable for the specified iterable

Since:

5.0

concatenate

public static <T> org.eclipse.collections.api.LazyIterable<T> concatenate(Iterable<T>... iterables)

Combines iterables into a deferred composite iterable

empty

public static <T> org.eclipse.collections.api.LazyIterable<T> empty()

zip

public static <A,B> org.eclipse.collections.api.LazyIterable<org.eclipse.collections.api.tuple.Pair<A,B>> zip(Iterable<A> as,
                                                                                                              Iterable<B> bs)

zipWithIndex

public static <T> org.eclipse.collections.api.LazyIterable<org.eclipse.collections.api.tuple.Pair<T,Integer>> zipWithIndex(Iterable<T> iterable)

chunk

public static <T> org.eclipse.collections.api.LazyIterable<org.eclipse.collections.api.RichIterable<T>> chunk(Iterable<T> iterable,
                                                                                                              int size)

tap

public static <T> org.eclipse.collections.api.LazyIterable<T> tap(Iterable<T> iterable,
                                                                  org.eclipse.collections.api.block.procedure.Procedure<? super T> procedure)

Creates a deferred tap iterable for the specified iterable.

Since:

6.0