Class Collections2.PermutationIterator<E>

  • All Implemented Interfaces:
    java.util.Iterator<java.util.List<E>>
    Enclosing class:
    Collections2

    private static class Collections2.PermutationIterator<E>
    extends AbstractIterator<java.util.List<E>>
    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) int[] c  
      (package private) int j  
      (package private) java.util.List<E> list  
      (package private) int[] o  
    • Constructor Summary

      Constructors 
      Constructor Description
      PermutationIterator​(java.util.List<E> list)  
    • Field Detail

      • list

        final java.util.List<E> list
      • c

        final int[] c
      • o

        final int[] o
      • j

        int j
    • Constructor Detail

      • PermutationIterator

        PermutationIterator​(java.util.List<E> list)
    • Method Detail

      • computeNext

        @CheckForNull
        protected java.util.List<E> computeNext()
        Description copied from class: AbstractIterator
        Returns the next element. Note: the implementation must call AbstractIterator.endOfData() when there are no elements left in the iteration. Failure to do so could result in an infinite loop.

        The initial invocation of AbstractIterator.hasNext() or AbstractIterator.next() calls this method, as does the first invocation of hasNext or next following each successful call to next. Once the implementation either invokes endOfData or throws an exception, computeNext is guaranteed to never be called again.

        If this method throws an exception, it will propagate outward to the hasNext or next invocation that invoked this method. Any further attempts to use the iterator will result in an IllegalStateException.

        The implementation of this method may not invoke the hasNext, next, or AbstractIterator.peek() methods on this instance; if it does, an IllegalStateException will result.

        Specified by:
        computeNext in class AbstractIterator<java.util.List<E>>
        Returns:
        the next element if there was one. If endOfData was called during execution, the return value will be ignored.
      • calculateNextPermutation

        void calculateNextPermutation()
      • switchDirection

        void switchDirection()