Package groovy.lang

Class ListWithDefault<T>

  • All Implemented Interfaces:
    Iterable<T>, Collection<T>, List<T>
    public final class ListWithDefault<T>
extends Object
implements List<T>
    A wrapper for List which automatically grows the list when either get(int) or getAt(int) is called with an index greater than or equal to size().
    Since:
    1.8.7

    • Method Detail

      • getDelegate

        public List<T> getDelegate()

      • isLazyDefaultValues

        public boolean isLazyDefaultValues()

      • getInitClosure

        public Closure getInitClosure()

      • newInstance

        public static <T> ListWithDefault<T> newInstance​(List<T> items,
                                                 boolean lazyDefaultValues,
                                                 Closure initClosure)

      • add

        public boolean add​(T t)
        Specified by:
        add in interface Collection<T>
        Specified by:
        add in interface List<T>

      • addAll

        public boolean addAll​(int i,
                      Collection<? extends T> ts)
        Specified by:
        addAll in interface List<T>

      • getAt

        public T getAt​(int index)
        Overwrites subscript operator handling by redirecting to get(int).
        Parameters:
        index - an index (might be greater or equal to size(), or smaller than 0)
        Returns:
        the value at the given index or the default value

      • get

        public T get​(int index)
        Returns the element at the given index but grows the list if needed. If the requested index is greater than or equal to size(), the list will grow to the new size and a default value calculated using the initClosure will be used to populate the missing value and returned.

        If lazyDefaultValues is true any gaps when growing the list are filled with nulls. Subsequent attempts to retrieve items from the list from those gap index values will, upon finding null, call the initClosure to populate the list for the given list value. Hence, when in this mode, nulls cannot be stored in this list. If lazyDefaultValues is false any gaps when growing the list are filled eagerly by calling the initClosure for all gap indexes during list growth. No calls to initClosure are made except during list growth and it is ok to store null values in the list when in this mode.

        This implementation breaks the contract of List.get(int) as it a) possibly modifies the underlying list and b) does NOT throw an IndexOutOfBoundsException when index < 0 || index >= size().

        Specified by:
        get in interface List<T>
        Parameters:
        index - an index (might be greater or equal to size(), or smaller than 0)
        Returns:
        the value at the given index or the default value

      • set

        public T set​(int i,
             T t)
        Specified by:
        set in interface List<T>

      • add

        public void add​(int i,
                T t)
        Specified by:
        add in interface List<T>

      • remove

        public T remove​(int i)
        Specified by:
        remove in interface List<T>

      • subList

        public ListWithDefault<T> subList​(int fromIndex,
                                  int toIndex)
        Returns a view of a portion of this list. This method returns a list with the same lazy list settings as the original list.
        Specified by:
        subList in interface List<T>
        Parameters:
        fromIndex - low endpoint of the subList (inclusive)
        toIndex - upper endpoint of the subList (exclusive)
        Returns:
        a view of a specified range within this list, keeping all lazy list settings