Package it.unimi.dsi.fastutil

Interface Stack<K>

All Known Subinterfaces:
BooleanStack, ByteStack, CharStack, DoubleStack, FloatStack, IntStack, LongStack, ShortStack
All Known Implementing Classes:
AbstractBooleanBigList, AbstractBooleanBigList.BooleanSubList, AbstractBooleanList, AbstractBooleanList.BooleanSubList, AbstractBooleanStack, AbstractByteBigList, AbstractByteBigList.ByteSubList, AbstractByteList, AbstractByteList.ByteSubList, AbstractByteStack, AbstractCharBigList, AbstractCharBigList.CharSubList, AbstractCharList, AbstractCharList.CharSubList, AbstractCharStack, AbstractDoubleBigList, AbstractDoubleBigList.DoubleSubList, AbstractDoubleList, AbstractDoubleList.DoubleSubList, AbstractDoubleStack, AbstractFloatBigList, AbstractFloatBigList.FloatSubList, AbstractFloatList, AbstractFloatList.FloatSubList, AbstractFloatStack, AbstractIntBigList, AbstractIntBigList.IntSubList, AbstractIntList, AbstractIntList.IntSubList, AbstractIntStack, AbstractLongBigList, AbstractLongBigList.LongSubList, AbstractLongList, AbstractLongList.LongSubList, AbstractLongStack, AbstractObjectBigList, AbstractObjectBigList.ObjectSubList, AbstractObjectList, AbstractObjectList.ObjectSubList, AbstractReferenceBigList, AbstractReferenceBigList.ReferenceSubList, AbstractReferenceList, AbstractReferenceList.ReferenceSubList, AbstractShortBigList, AbstractShortBigList.ShortSubList, AbstractShortList, AbstractShortList.ShortSubList, AbstractShortStack, AbstractStack, BooleanArrayList, BooleanBigArrayBigList, BooleanBigLists.ListBigList, BooleanBigLists.Singleton, BooleanLists.Singleton, ByteArrayFrontCodedList, ByteArrayList, ByteBigArrayBigList, ByteBigLists.ListBigList, ByteBigLists.Singleton, ByteLists.Singleton, CharArrayFrontCodedList, CharArrayList, CharBigArrayBigList, CharBigLists.ListBigList, CharBigLists.Singleton, CharLists.Singleton, DoubleArrayList, DoubleBigArrayBigList, DoubleBigLists.ListBigList, DoubleBigLists.Singleton, DoubleLists.Singleton, FloatArrayList, FloatBigArrayBigList, FloatBigLists.ListBigList, FloatBigLists.Singleton, FloatLists.Singleton, IntArrayFrontCodedList, IntArrayList, IntBigArrayBigList, IntBigLists.ListBigList, IntBigLists.Singleton, IntLists.Singleton, LongArrayFrontCodedList, LongArrayList, LongBigArrayBigList, LongBigLists.ListBigList, LongBigLists.Singleton, LongLists.Singleton, ObjectArrayList, ObjectBigArrayBigList, ObjectBigLists.ListBigList, ObjectBigLists.Singleton, ObjectLists.Singleton, ReferenceArrayList, ReferenceBigArrayBigList, ReferenceBigLists.ListBigList, ReferenceBigLists.Singleton, ReferenceLists.Singleton, ShortArrayFrontCodedList, ShortArrayList, ShortBigArrayBigList, ShortBigLists.ListBigList, ShortBigLists.Singleton, ShortLists.Singleton
public interface Stack<K>
A stack.

A stack must provide the classical push(Object) and pop() operations, but may be also peekable to some extent: it may provide just the top() function, or even a more powerful peek(int) method that provides access to all elements on the stack (indexed from the top, which has index 0).

  • Method Summary

    Modifier and Type Method Description
    boolean isEmpty()
    Checks whether the stack is empty.
    default K peek​(int i)
    Peeks at an element on the stack (optional operation).
    K pop()
    Pops the top off the stack.
    void push​(K o)
    Pushes the given object on the stack.
    default K top()
    Peeks at the top of the stack (optional operation).

  • Method Details

    • push

      void push​(K o)
      Pushes the given object on the stack.
      Parameters:
      o - the object that will become the new top of the stack.

    • pop

      K pop()
      Pops the top off the stack.
      Returns:
      the top of the stack.
      Throws:
      NoSuchElementException - if the stack is empty.

    • isEmpty

      boolean isEmpty()
      Checks whether the stack is empty.
      Returns:
      true if the stack is empty.

    • top

      default K top()
      Peeks at the top of the stack (optional operation).

      This default implementation returns peek(0).

      Returns:
      the top of the stack.
      Throws:
      NoSuchElementException - if the stack is empty.

    • peek

      default K peek​(int i)
      Peeks at an element on the stack (optional operation).

      This default implementation just throws an UnsupportedOperationException.

      Parameters:
      i - an index from the stop of the stack (0 represents the top).
      Returns:
      the i-th element on the stack.
      Throws:
      IndexOutOfBoundsException - if the designated element does not exist..