Class GroovyCollections

java.lang.Object
groovy.util.GroovyCollections
public class GroovyCollections extends Object
A Collections utility class
Author:
Paul King, Jim White

  • Constructor Summary

    Constructors
    Constructor
    Description
    GroovyCollections()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static List
    combinations(Object[] collections)
    Finds all combinations of items from the given collections.
    static List
    combinations(Collection collections)
    Finds all combinations of items from the given collections.
    static <T> T
    max(Collection<T> items)
    Selects the maximum value found in a collection
    static <T> T
    max(T[] items)
    Selects the maximum value found in an array of items, so min([2, 4, 6] as Object[]) == 6.
    static <T> T
    min(Collection<T> items)
    Selects the minimum value found in a collection of items.
    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(Object[] items)
    Sums all the items from an array of items.
    static Object
    sum(Collection items)
    Sums all the items from a collection of items.
    static List
    transpose(Object[] lists)
    Transposes an array of lists.
    static List
    transpose(List lists)
    Transposes the given lists.

    Methods inherited from class Object

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

  • Constructor Details

    • GroovyCollections

      public GroovyCollections()

  • Method Details

    • 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:

    • 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

      public static List combinations(Collection collections)
      Finds all combinations of items from the given 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']].
      Parameters:
      collections - the given collections
      Returns:
      a List of the combinations found

    • 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

      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

      public static <T> T min(Collection<T> items)
      Selects the minimum value found in a collection of items.
      Parameters:
      items - a Collection
      Returns:
      the minimum value

    • max

      public static <T> T max(T[] items)
      Selects the maximum value found in an array of items, so min([2, 4, 6] as Object[]) == 6.
      Parameters:
      items - an array of items
      Returns:
      the maximum value

    • max

      public static <T> T max(Collection<T> items)
      Selects the maximum value found in a collection
      Parameters:
      items - a Collection
      Returns:
      the maximum value

    • 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

      public static Object sum(Collection items)
      Sums all the items from a collection of items.
      Parameters:
      items - a collection of items
      Returns:
      the sum of the items