fj.data

Class NonEmptyList<A>

java.lang.Object

fj.data.NonEmptyList<A>

All Implemented Interfaces:

java.lang.Iterable<A>

public final class NonEmptyList<A>
extends java.lang.Object
implements java.lang.Iterable<A>

Provides an in-memory, immutable, singly linked list with total head and tail.

Field Summary

Fields

Modifier and Type	Field and Description
A	head The first element of this linked list.
List<A>	tail This list without the first element.

Method Summary

Methods

Modifier and Type	Method and Description
NonEmptyList<A>	append(NonEmptyList<A> as) Appends the given list to this list.
<B> NonEmptyList<B>	bind(F<A,NonEmptyList<B>> f) Binds the given function across each element of this list with a final join.
NonEmptyList<A>	cons(A a) Prepend the given value to this list.
static <A> Option<NonEmptyList<A>>	fromList(List<A> as) Returns a potential non-empty list from the given list.
java.util.Iterator<A>	iterator() Returns an iterator for this non-empty list.
<B> NonEmptyList<B>	map(F<A,B> f) Maps the given function across this list.
<B> NonEmptyList<B>	mapTails(F<NonEmptyList<A>,B> f) Maps the given function across the tails of this list (comonad pattern).
static <A> F<A,NonEmptyList<A>>	nel() Returns a function that puts an element into a non-empty list.
static <A> NonEmptyList<A>	nel(A head) Return a non-empty list with the given value.
static <A> NonEmptyList<A>	nel(A head, List<A> tail) Return a non-empty list with the given head and tail.
NonEmptyList<NonEmptyList<A>>	sublists() Returns a NonEmptyList of the sublists of this list.
NonEmptyList<NonEmptyList<A>>	tails() Returns a NonEmptyList of the tails of this list.
java.util.Collection<A>	toCollection() Projects an immutable collection of this non-empty list.
static <A> F<NonEmptyList<A>,List<A>>	toList_() Returns a function that takes a non-empty list to a list.
List<A>	toList() Returns a List projection of this list.

Methods inherited from class java.lang.Object

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

Field Detail

head

public final A head

The first element of this linked list.

tail

public final List<A> tail

This list without the first element.

Method Detail

iterator

public java.util.Iterator<A> iterator()

Returns an iterator for this non-empty list. This method exists to permit the use in a for-each loop.

Specified by:

iterator in interface java.lang.Iterable<A>

Returns:

A iterator for this non-empty list.

cons

public NonEmptyList<A> cons(A a)

Prepend the given value to this list.

Parameters:

a - The value to prepend.

Returns:

A non-empty list with an extra element.

append

public NonEmptyList<A> append(NonEmptyList<A> as)

Appends the given list to this list.

Parameters:

as - The list to append.

Returns:

A new list with the given list appended.

map

public <B> NonEmptyList<B> map(F<A,B> f)

Maps the given function across this list.

Parameters:

f - The function to map across this list.

Returns:

A new list after the given function has been applied to each element.

bind

public <B> NonEmptyList<B> bind(F<A,NonEmptyList<B>> f)

Binds the given function across each element of this list with a final join.

Parameters:

f - The function to apply to each element of this list.

Returns:

A new list after performing the map, then final join.

sublists

public NonEmptyList<NonEmptyList<A>> sublists()

Returns a NonEmptyList of the sublists of this list.

Returns:

a NonEmptyList of the sublists of this list.

tails

public NonEmptyList<NonEmptyList<A>> tails()

Returns a NonEmptyList of the tails of this list. A list is considered a tail of itself for the purpose of this function (Comonad pattern).

Returns:

A NonEmptyList of the tails of this list.

mapTails

public <B> NonEmptyList<B> mapTails(F<NonEmptyList<A>,B> f)

Maps the given function across the tails of this list (comonad pattern).

Parameters:

f - The function to map across the tails of this list.

Returns:

The results of applying the given function to the tails of this list, as a NonEmptyList.

toList

public List<A> toList()

Returns a List projection of this list.

Returns:

A List projection of this list.

toCollection

public java.util.Collection<A> toCollection()

Projects an immutable collection of this non-empty list.

Returns:

An immutable collection of this non-empty list.

toList_

public static <A> F<NonEmptyList<A>,List<A>> toList_()

Returns a function that takes a non-empty list to a list.

Returns:

A function that takes a non-empty list to a list.

nel

public static <A> NonEmptyList<A> nel(A head,
                      List<A> tail)

Return a non-empty list with the given head and tail.

Parameters:

head - The first element of the new list.

tail - The remaining elements of the new list.

Returns:

A non-empty list with the given head and tail.

nel

public static <A> NonEmptyList<A> nel(A head)

Return a non-empty list with the given value.

Parameters:

head - The value in the non-empty list.

Returns:

A non-empty list with the given value.

nel

public static <A> F<A,NonEmptyList<A>> nel()

Returns a function that puts an element into a non-empty list.

Returns:

A function that puts an element into a non-empty list.

fromList

public static <A> Option<NonEmptyList<A>> fromList(List<A> as)

Returns a potential non-empty list from the given list. A non-value is returned if the given list is empty.

Parameters:

as - The list to construct a potential non-empty list with.

Returns:

A potential non-empty list from the given list.