org.avis.util
Class Collections

java.lang.Object
  org.avis.util.Collections

public final class Collections
extends Object

General collection utilities.

Author:

Matthew Phillips

Method Summary

static <T> Set<T>	difference(Set<T> set1, Set<T> set2) Compute the difference between set1 and set2.
static void	join(StringBuilder str, Iterable<?> items, char separator) Join a collection of items with a separator and append to a string builder.
static <E> List<E>	list(E... items) Create an immutable list from a number of items.
static <E> Map<E,E>	map(E... pairs) Create an immutable map from a number of item pairs: even items are keys, their adjacent items are values.
static <E> Set<E>	set(E... items) Create an immutable set from a number of items.
static <K,V> Map<K,V>	union(Map<K,V> map1, Map<K,V> map2) Compute the union of map1 and map2.
static <T> Set<T>	union(Set<T> set1, Set<T> set2) Compute the union of set1 and set2.

Methods inherited from class java.lang.Object

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

Method Detail

set

public static <E> Set<E> set(E... items)

Create an immutable set from a number of items.

list

public static <E> List<E> list(E... items)

Create an immutable list from a number of items.

map

public static <E> Map<E,E> map(E... pairs)

Create an immutable map from a number of item pairs: even items are keys, their adjacent items are values.

join

public static void join(StringBuilder str,
                        Iterable<?> items,
                        char separator)

Join a collection of items with a separator and append to a string builder.

difference

public static <T> Set<T> difference(Set<T> set1,
                                    Set<T> set2)

Compute the difference between set1 and set2. This is not guaranteed to generate a new set instance.

union

public static <T> Set<T> union(Set<T> set1,
                               Set<T> set2)

Compute the union of set1 and set2. This is not guaranteed to generate a new set instance: it will return set1 or set2 directly if the other set is empty.

union

public static <K,V> Map<K,V> union(Map<K,V> map1,
                                   Map<K,V> map2)

Compute the union of map1 and map2. This is not guaranteed to generate a new map instance: it will return map1 or map2 directly if the other map is empty. If there is a key/value overlap, map2 wins.