net.emaze.dysfunctional

Class Filtering

java.lang.Object

net.emaze.dysfunctional.Filtering

public abstract class Filtering
extends Object

filter, takeLast, atMostLast, takeWhile, dropWhile, take, drop, slice.

Author:

rferranti

Constructor Summary

Constructors

Constructor and Description
Filtering()

Method Summary

Modifier and Type	Method and Description
static <E> Iterator<E>	atMostLast(int howMany, E[] from) Creates an iterator yielding at most last n elements from the source array.
static <E> Iterator<E>	atMostLast(int howMany, Iterable<E> from) Creates an iterator yielding at most last n elements from the source iterable.
static <E> Iterator<E>	atMostLast(int howMany, Iterator<E> from) Creates an iterator yielding at most last n elements from the source iterator.
static <E> Iterator<E>	drop(long howMany, E... array) Creates an iterator yielding all but first n elements from the passed array.
static <E> Iterator<E>	drop(long howMany, Iterable<E> iterable) Creates an iterator yielding all but first n elements from the passed iterable.
static <E> Iterator<E>	drop(long howMany, Iterator<E> iterator) Creates an iterator yielding all but first n elements from the passed iterator.
static <E> Iterator<E>	dropWhile(E[] array, Predicate<E> predicate) Creates an iterator yielding values from the source array up until the passed predicate doesn't match.
static <E> Iterator<E>	dropWhile(Iterable<E> iterable, Predicate<E> predicate) Creates an iterator yielding values from the source iterable up until the passed predicate doesn't match.
static <E> Iterator<E>	dropWhile(Iterator<E> iterator, Predicate<E> predicate) Creates an iterator yielding values from the source iterator up until the passed predicate doesn't match.
static <E> Iterator<E>	filter(E[] array, Predicate<E> predicate) Creates an iterator yielding elements from the source array matching the given predicate.
static <E> Iterator<E>	filter(Iterable<E> iterable, Predicate<E> predicate) Creates an iterator yielding elements from the source iterable matching the given predicate.
static <E> Iterator<E>	filter(Iterator<E> iterator, Predicate<E> predicate) Creates an iterator yielding elements from the source iterator matching the given predicate.
static <E> Iterator<E>	slice(long from, long howMany, E... array) Creates an iterator yielding a slice of the source array.
static <E> Iterator<E>	slice(long from, long howMany, Iterable<E> iterable) Creates an iterator yielding a slice of the source iterable.
static <E> Iterator<E>	slice(long from, long howMany, Iterator<E> iterator) Creates an iterator yielding a slice of the source iterator.
static <E> Iterator<E>	take(long howMany, E... array) Creates an iterator yielding at most first n elements of the passed array.
static <E> Iterator<E>	take(long howMany, Iterable<E> iterable) Creates an iterator yielding at most first n elements of the passed iterable.
static <E> Iterator<E>	take(long howMany, Iterator<E> iterator) Creates an iterator yielding at most first n elements of the passed iterator.
static <E> Iterator<E>	takeLast(int howMany, E[] from) Creates an iterator yielding last n elements from the source array.
static <E> Iterator<E>	takeLast(int howMany, Iterable<E> from) Creates an iterator yielding last n elements from the source iterable.
static <E> Iterator<E>	takeLast(int howMany, Iterator<E> from) Creates an iterator yielding last n elements from the source iterator.
static <E> Iterator<E>	takeWhile(E[] array, Predicate<E> predicate) Creates an iterator yielding values from the source array up until the passed predicate matches.
static <E> Iterator<E>	takeWhile(Iterable<E> iterable, Predicate<E> predicate) Creates an iterator yielding values from the source iterable up until the passed predicate matches.
static <E> Iterator<E>	takeWhile(Iterator<E> iterator, Predicate<E> predicate) Creates an iterator yielding values from the source iterator up until the passed predicate matches.

Methods inherited from class java.lang.Object

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

Constructor Detail

Filtering

public Filtering()

Method Detail

filter

public static <E> Iterator<E> filter(Iterator<E> iterator,
                                     Predicate<E> predicate)

Creates an iterator yielding elements from the source iterator matching the given predicate. This transformation is applied lazily and the predicate is applied while consuming returned iterator. E.g: filter([1,2,3,4], isEven) -> [2,4]

Type Parameters:

E - the iterator element type

Parameters:

iterator - the iterator where elements are fetched from

predicate - the predicate applied to each element

Returns:

an iterator containing the elements for which the predicate evaluates to true

filter

public static <E> Iterator<E> filter(Iterable<E> iterable,
                                     Predicate<E> predicate)

Creates an iterator yielding elements from the source iterable matching the given predicate. This transformation is applied lazily and the predicate is applied while consuming returned iterator. E.g: filter([1,2,3,4], isEven) -> [2,4]

Type Parameters:

E - the iterable element type

Parameters:

iterable - the iterable where elements are fetched from

predicate - the predicate applied to each element

Returns:

an iterator containing the elements for which the predicate evaluates to true

filter

public static <E> Iterator<E> filter(E[] array,
                                     Predicate<E> predicate)

Creates an iterator yielding elements from the source array matching the given predicate. This transformation is applied lazily and the predicate is applied while consuming returned iterator. E.g: filter([1,2,3,4], isEven) -> [2,4]

Type Parameters:

E - the array element type

Parameters:

array - the array where elements are fetched from

predicate - the predicate applied to each element

Returns:

an Iterator containing the elements for which the predicate evaluates to true

takeLast

public static <E> Iterator<E> takeLast(int howMany,
                                       Iterable<E> from)

Creates an iterator yielding last n elements from the source iterable. Consuming the resulting iterator yields an IllegalArgumentException if not enough elements can be fetched. E.g: takeLast(2, [1, 2, 3]) -> [2, 3]

Type Parameters:

E - the iterable element type

Parameters:

howMany - number of elements to be yielded

from - the source iterable

Returns:

the resulting iterator

takeLast

public static <E> Iterator<E> takeLast(int howMany,
                                       Iterator<E> from)

Creates an iterator yielding last n elements from the source iterator. Consuming the resulting iterator yields an IllegalArgumentException if not enough elements can be fetched. E.g: takeLast(2, [1, 2, 3]) -> [2, 3]

Type Parameters:

E - the iterator element type

Parameters:

howMany - number of elements to be yielded

from - the source iterator

Returns:

the resulting iterator

takeLast

public static <E> Iterator<E> takeLast(int howMany,
                                       E[] from)

Creates an iterator yielding last n elements from the source array. Consuming the resulting iterator yields an IllegalArgumentException if not enough elements can be fetched. E.g: takeLast(2, [1, 2, 3]) -> [2, 3]

Type Parameters:

E - the array element type

Parameters:

howMany - number of elements to be yielded

from - the source array

Returns:

the resulting iterator

atMostLast

public static <E> Iterator<E> atMostLast(int howMany,
                                         Iterable<E> from)

Creates an iterator yielding at most last n elements from the source iterable. E.g: atMostLast(4, [1, 2, 3]) -> [1, 2, 3] atMostLast(2, [1, 2, 3]) -> [2, 3]

Type Parameters:

E - the iterable element type

Parameters:

howMany - number of elements to be yielded (at most)

from - the source iterable

Returns:

the resulting iterator

atMostLast

public static <E> Iterator<E> atMostLast(int howMany,
                                         Iterator<E> from)

Creates an iterator yielding at most last n elements from the source iterator. E.g: atMostLast(4, [1, 2, 3]) -> [1, 2, 3] atMostLast(2, [1, 2, 3]) -> [2, 3]

Type Parameters:

E - the iterator element type

Parameters:

howMany - number of elements to be yielded (at most)

from - the source iterator

Returns:

the resulting iterator

atMostLast

public static <E> Iterator<E> atMostLast(int howMany,
                                         E[] from)

Creates an iterator yielding at most last n elements from the source array. E.g: atMostLast(4, [1, 2, 3]) -> [1, 2, 3] atMostLast(2, [1, 2, 3]) -> [2, 3]

Type Parameters:

E - the array element type

Parameters:

howMany - number of elements to be yielded (at most)

from - the source array

Returns:

the resulting iterator

takeWhile

public static <E> Iterator<E> takeWhile(Iterator<E> iterator,
                                        Predicate<E> predicate)

Creates an iterator yielding values from the source iterator up until the passed predicate matches. E.g: takeWhile([2, 4, 3, 6], isEven) -> [2, 4]

Type Parameters:

E - the iterator element type

Parameters:

iterator - the source iterator

predicate - the predicate to be evaluated

Returns:

the resulting iterator

takeWhile

public static <E> Iterator<E> takeWhile(Iterable<E> iterable,
                                        Predicate<E> predicate)

Creates an iterator yielding values from the source iterable up until the passed predicate matches. E.g: takeWhile([2, 4, 3, 6], isEven) -> [2, 4]

Type Parameters:

E - the iterable element type

Parameters:

iterable - the source iterable

predicate - the predicate to be evaluated

Returns:

the resulting iterator

takeWhile

public static <E> Iterator<E> takeWhile(E[] array,
                                        Predicate<E> predicate)

Creates an iterator yielding values from the source array up until the passed predicate matches. E.g: takeWhile([2, 4, 3, 6], isEven) -> [2, 4]

Type Parameters:

E - the array element type

Parameters:

array - the source iterable

predicate - the predicate to be evaluated

Returns:

the resulting iterator

dropWhile

public static <E> Iterator<E> dropWhile(Iterator<E> iterator,
                                        Predicate<E> predicate)

Creates an iterator yielding values from the source iterator up until the passed predicate doesn't match. E.g: dropWhile([2, 4, 3, 6], isOdd) -> [2, 4]

Type Parameters:

E - the iterator element type

Parameters:

iterator - the source iterator

predicate - the predicate to be evaluated

Returns:

the resulting iterator

dropWhile

public static <E> Iterator<E> dropWhile(Iterable<E> iterable,
                                        Predicate<E> predicate)

Creates an iterator yielding values from the source iterable up until the passed predicate doesn't match. E.g: dropWhile([2, 4, 3, 6], isOdd) -> [2, 4]

Type Parameters:

E - the iterable element type

Parameters:

iterable - the source iterable

predicate - the predicate to be evaluated

Returns:

the resulting iterator

dropWhile

public static <E> Iterator<E> dropWhile(E[] array,
                                        Predicate<E> predicate)

Creates an iterator yielding values from the source array up until the passed predicate doesn't match. E.g: dropWhile([2, 4, 3, 6], isOdd) -> [2, 4]

Type Parameters:

E - the array element type

Parameters:

array - the source array

predicate - the predicate to be evaluated

Returns:

the resulting iterator

take

public static <E> Iterator<E> take(long howMany,
                                   Iterator<E> iterator)

Creates an iterator yielding at most first n elements of the passed iterator. E.g: take(2, [1, 2, 3]) -> [1, 2] take(4, [1, 2, 3]) -> [1, 2, 3]

Type Parameters:

E - the iterator element type

Parameters:

howMany - elements to be consumed (at most)

iterator - the source iterator

Returns:

the resulting iterator

take

public static <E> Iterator<E> take(long howMany,
                                   Iterable<E> iterable)

Creates an iterator yielding at most first n elements of the passed iterable. E.g: take(2, [1, 2, 3]) -> [1, 2] take(4, [1, 2, 3]) -> [1, 2, 3]

Type Parameters:

E - the iterable element type

Parameters:

howMany - elements to be consumed (at most)

iterable - the source iterable

Returns:

the resulting iterator

take

public static <E> Iterator<E> take(long howMany,
                                   E... array)

Creates an iterator yielding at most first n elements of the passed array. E.g: take(2, [1, 2, 3]) -> [1, 2] take(4, [1, 2, 3]) -> [1, 2, 3]

Type Parameters:

E - the array element type

Parameters:

howMany - elements to be consumed (at most)

array - the source array

Returns:

the resulting iterator

drop

public static <E> Iterator<E> drop(long howMany,
                                   Iterator<E> iterator)

Creates an iterator yielding all but first n elements from the passed iterator. E.g: drop(3, [1,2,3,4]) -> [4]

Type Parameters:

E - the iterator element type

Parameters:

howMany - elements to be discarded

iterator - the source iterator

Returns:

the resulting iterator

drop

public static <E> Iterator<E> drop(long howMany,
                                   Iterable<E> iterable)

Creates an iterator yielding all but first n elements from the passed iterable. E.g: drop(3, [1,2,3,4]) -> [4]

Type Parameters:

E - the iterator element type

Parameters:

howMany - elements to be discarded

iterable - the source iterable

Returns:

the resulting iterator

drop

public static <E> Iterator<E> drop(long howMany,
                                   E... array)

Creates an iterator yielding all but first n elements from the passed array. E.g: drop(3, [1,2,3,4]) -> [4]

Type Parameters:

E - the iterator element type

Parameters:

howMany - elements to be discarded

array - the source array

Returns:

the resulting iterator

slice

public static <E> Iterator<E> slice(long from,
                                    long howMany,
                                    Iterator<E> iterator)

Creates an iterator yielding a slice of the source iterator. E.g: slice(1, 2, ["a", "b", "c", "d"]) -> ["b", "c"]

Type Parameters:

E - the iterator element type

Parameters:

from - the index at which the slice starts

howMany - the slice size (at most)

iterator - the source iterator

Returns:

the resulting iterator

slice

public static <E> Iterator<E> slice(long from,
                                    long howMany,
                                    Iterable<E> iterable)

Creates an iterator yielding a slice of the source iterable. E.g: slice(1, 2, ["a", "b", "c", "d"]) -> ["b", "c"]

Type Parameters:

E - the iterator element type

Parameters:

from - the index at which the slice starts

howMany - the slice size (at most)

iterable - the source iterable

Returns:

the resulting iterator

slice

public static <E> Iterator<E> slice(long from,
                                    long howMany,
                                    E... array)

Creates an iterator yielding a slice of the source array. E.g: slice(1, 2, ["a", "b", "c", "d"]) -> ["b", "c"]

Type Parameters:

E - the iterator element type

Parameters:

from - the index at which the slice starts

howMany - the slice size (at most)

array - the source array

Returns:

the resulting iterator