Package net.cscott.jutil

Interface ListFactory<V>

All Superinterfaces:

CollectionFactory<V>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ListFactory<V>
extends CollectionFactory<V>

ListFactory is a List generator. Implementations construct specific types of Lists. It is a functional interface, so a constructor which copies a collection is a ListFactory: ArrayList::new. ListFactory also has a set of static helper methods for building List objects.

Note also that the current limitations on parametric types in Java mean that we can't easily type this class as ListFactory<L extends List<V>,V>, as ListFactory<LinkedList<V>,V> is not a subtype of ListFactory<List<V>,V>, even though LinkedList is a subtype of List.

Author:

Felix S. Klock II <pnkfelix@mit.edu>

Method Summary

Modifier and Type	Method	Description
static <E> List<E>	concatenate(List<List<E>> lists)	Creates and returns an unmodifiable List view of the list made from connecting lists together in order.
default List<V>	makeCollection()	Generates a new, mutable, empty Collection.
default List<V>	makeCollection(int initCapacity)	Generates a new, mutable, empty Collection, using initialCapacity as a hint to use for the capacity for the produced Collection.
default List<V>	makeCollection(Collection<? extends V> c)	Generates a new, mutable Collection, using the elements of c as a template for its initial contents.
default List<V>	makeList()	Generates a new, mutable, empty List.
default List<V>	makeList(int initialCapacity)	Generates a new, mutable, empty List, using initialCapacity as a hint to use for the capacity for the produced List.
List<V>	makeList(Collection<? extends V> c)	Generates a new mutable List, using the elements of c as a template for its initial contents.
static <E> List<E>	singleton(E o)	Deprecated. Use Collections.singletonList instead.

Method Details

makeCollection

default List<V> makeCollection()

Description copied from interface: CollectionFactory

Generates a new, mutable, empty Collection.

Specified by:

makeCollection in interface CollectionFactory<V>

makeCollection

default List<V> makeCollection(int initCapacity)

Description copied from interface: CollectionFactory

Generates a new, mutable, empty Collection, using initialCapacity as a hint to use for the capacity for the produced Collection.

Specified by:

makeCollection in interface CollectionFactory<V>

makeCollection

default List<V> makeCollection(Collection<? extends V> c)

Description copied from interface: CollectionFactory

Generates a new, mutable Collection, using the elements of c as a template for its initial contents. Note that the Collection returned is not a view of c, but rather a snapshot; changes to c are not reflected in the returned Collection.

Specified by:

makeCollection in interface CollectionFactory<V>

makeList

default List<V> makeList()

Generates a new, mutable, empty List.

makeList

default List<V> makeList(int initialCapacity)

Generates a new, mutable, empty List, using initialCapacity as a hint to use for the capacity for the produced List.

makeList

List<V> makeList(Collection<? extends V> c)

Generates a new mutable List, using the elements of c as a template for its initial contents.

concatenate

static <E> List<E> concatenate(List<List<E>> lists)

Creates and returns an unmodifiable List view of the list made from connecting lists together in order.
requires: lists is a List of Lists.
effects:

let l0 = (List) lists.get(0)
                 l1 = (List) lists.get(1)
                 ...
                 ln = (List) lists.get(n) where n is lists.size()-1
             returns a list view
                 [ l0.get(0) , l0.get(1), ... , l0.get(l0.size()-1), 
                   l1.get(0) , l1.get(1), ... , l1.get(l1.size()-1),
                   ...
                   ln.get(0) , ln.get(1), ... , ln.get(ln.size()-1) ]
        

Note that not only changes to the elements of lists are reflected in the returned List, but even changes to lists itself (adding or removing lists) are also reflected.

singleton

@Deprecated(since="1.3")
static <E> List<E> singleton(E o)

Deprecated.

Use Collections.singletonList instead.

Creates and returns an immutable List of one element.
effects: returns the list [ o ]