Package groovy.util

Class GroovyCollections

java.lang.Object

groovy.util.GroovyCollections

public class GroovyCollections
extends Object

A Collections utility class

Constructor Summary

Constructors

Constructor	Description
GroovyCollections()

Method Summary

Modifier and Type	Method	Description
static List	combinations(Iterable collections)	Finds all combinations of items from the given Iterable aggregate of collections.
static List	combinations(Object[] collections)	Finds all combinations of items from the given collections.
static List	combinations(Collection collections)	Deprecated. use combinations(Iterable)
static <T> List<List<T>>	inits(Iterable<T> collections)
static <T> T	max(Iterable<T> items)	Selects the maximum value found in an Iterable.
static <T> T	max(Collection<T> items)	Deprecated. use max(Iterable)
static <T> T	max(T[] items)	Selects the maximum value found in an array of items, so max([2, 4, 6] as Object[]) == 6.
static <T> T	min(Iterable<T> items)	Selects the minimum value found in an Iterable of items.
static <T> T	min(Collection<T> items)	Deprecated. use min(Iterable)
static <T> T	min(T[] items)	Selects the minimum value found in an array of items, so min([2, 4, 6] as Object[]) == 2.
static <T> Set<List<T>>	subsequences(List<T> items)	Finds all non-null subsequences of a list.
static Object	sum(Iterable items)	Sums all the given items.
static Object	sum(Object[] items)	Sums all the items from an array of items.
static Object	sum(Collection items)	Deprecated. use sum(Iterable)
static <T> List<List<T>>	tails(Iterable<T> collections)
static List	transpose(Object[] lists)	Transposes an array of lists.
static List	transpose(List lists)	Transposes the given lists.

Methods inherited from class java.lang.Object

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

Constructor Detail

GroovyCollections

public GroovyCollections()

Method Detail

combinations

public static List combinations(Object[] collections)

Finds all combinations of items from the given collections.

Parameters:

collections - the given collections

Returns:

a List of the combinations found

See Also:

combinations(Collection)

subsequences

public static <T> Set<List<T>> subsequences(List<T> items)

Finds all non-null subsequences of a list. E.g. subsequences([1, 2, 3]) would be: [[1, 2, 3], [1, 3], [2, 3], [1, 2], [1], [2], [3]]

Parameters:

items - the List of items

Returns:

the subsequences from items

combinations

@Deprecated
public static List combinations(Collection collections)

Deprecated.

use combinations(Iterable)

Parameters:

collections - the given collections

combinations

public static List combinations(Iterable collections)

Finds all combinations of items from the given Iterable aggregate of collections. So, combinations([[true, false], [true, false]]) is [[true, true], [false, true], [true, false], [false, false]] and combinations([['a', 'b'],[1, 2, 3]]) is [['a', 1], ['b', 1], ['a', 2], ['b', 2], ['a', 3], ['b', 3]]. If a non-collection item is given, it is treated as a singleton collection, i.e. combinations([[1, 2], 'x']) is [[1, 'x'], [2, 'x']]. If an empty collection is found within the given collections, the result will be an empty list.

Parameters:

collections - the Iterable of given collections

Returns:

a List of the combinations found

Since:

2.2.0

inits

public static <T> List<List<T>> inits(Iterable<T> collections)

tails

public static <T> List<List<T>> tails(Iterable<T> collections)

transpose

public static List transpose(Object[] lists)

Transposes an array of lists.

Parameters:

lists - the given lists

Returns:

a List of the transposed lists

See Also:

transpose(List)

transpose

public static List transpose(List lists)

Transposes the given lists. So, transpose([['a', 'b'], [1, 2]]) is [['a', 1], ['b', 2]] and transpose([['a', 'b', 'c']]) is [['a'], ['b'], ['c']].

Parameters:

lists - the given lists

Returns:

a List of the transposed lists

min

public static <T> T min(T[] items)

Selects the minimum value found in an array of items, so min([2, 4, 6] as Object[]) == 2.

Parameters:

items - an array of items

Returns:

the minimum value

min

@Deprecated
public static <T> T min(Collection<T> items)

Deprecated.

use min(Iterable)

min

public static <T> T min(Iterable<T> items)

Selects the minimum value found in an Iterable of items.

Parameters:

items - an Iterable

Returns:

the minimum value

Since:

2.2.0

max

public static <T> T max(T[] items)

Selects the maximum value found in an array of items, so max([2, 4, 6] as Object[]) == 6.

Parameters:

items - an array of items

Returns:

the maximum value

max

@Deprecated
public static <T> T max(Collection<T> items)

Deprecated.

use max(Iterable)

max

public static <T> T max(Iterable<T> items)

Selects the maximum value found in an Iterable.

Parameters:

items - a Collection

Returns:

the maximum value

Since:

2.2.0

sum

public static Object sum(Object[] items)

Sums all the items from an array of items.

Parameters:

items - an array of items

Returns:

the sum of the items

sum

@Deprecated
public static Object sum(Collection items)

Deprecated.

use sum(Iterable)

sum

public static Object sum(Iterable items)

Sums all the given items.

Parameters:

items - an Iterable of items

Returns:

the sum of the item

Since:

2.2.0