Class KillRing

java.lang.Object
org.jline.reader.impl.KillRing

public final class KillRing extends Object
The kill ring class keeps killed text in a fixed size ring. In this class we also keep record of whether or not the last command was a kill or a yank. Depending on this, the class may behave different. For instance, two consecutive kill-word commands fill the same slot such that the next yank will return the two previously killed words instead that only the last one. Likewise yank pop requires that the previous command was either a yank or a yank-pop.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private static final int
    Default size is 60, like in emacs.
    private int
     
    private boolean
     
    private boolean
     
    private final String[]
     
  • Constructor Summary

    Constructors
    Constructor
    Description
    Creates a new kill ring of the default size.
    KillRing(int size)
    Creates a new kill ring of the given size.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(String str)
    Adds the string to the kill-ring.
    void
    Adds the string to the kill-ring product of killing backwards.
    boolean
    Returns true if the last command was a yank.
    private void
    Moves the pointer to the current slot forward.
    private void
    Moves the pointer to the current slot backwards.
    void
    Resets the last-kill state.
    void
    Resets the last-yank state.
    Yanks a previously killed text.
    Moves the pointer to the current slot back and returns the text in that position.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • DEFAULT_SIZE

      private static final int DEFAULT_SIZE
      Default size is 60, like in emacs.
      See Also:
    • slots

      private final String[] slots
    • lastKill

      private boolean lastKill
    • lastYank

      private boolean lastYank
  • Constructor Details

    • KillRing

      public KillRing(int size)
      Creates a new kill ring of the given size.
      Parameters:
      size - the size of the ring
    • KillRing

      public KillRing()
      Creates a new kill ring of the default size. See DEFAULT_SIZE.
  • Method Details

    • resetLastYank

      public void resetLastYank()
      Resets the last-yank state.
    • resetLastKill

      public void resetLastKill()
      Resets the last-kill state.
    • lastYank

      public boolean lastYank()
      Returns true if the last command was a yank.
      Returns:
      true if the last command was a yank
    • add

      public void add(String str)
      Adds the string to the kill-ring. Also sets lastYank to false and lastKill to true.
      Parameters:
      str - the string to add
    • addBackwards

      public void addBackwards(String str)
      Adds the string to the kill-ring product of killing backwards. If the previous command was a kill text one then adds the text at the beginning of the previous kill to avoid that two consecutive backwards kills followed by a yank leaves things reversed.
      Parameters:
      str - the string to add
    • yank

      public String yank()
      Yanks a previously killed text. Returns null if the ring is empty.
      Returns:
      the text in the current position
    • yankPop

      public String yankPop()
      Moves the pointer to the current slot back and returns the text in that position. If the previous command was not yank returns null.
      Returns:
      the text in the previous position
    • next

      private void next()
      Moves the pointer to the current slot forward. If the end of the slots is reached then points back to the beginning.
    • prev

      private void prev()
      Moves the pointer to the current slot backwards. If the beginning of the slots is reached then traverses the slot backwards until one with not null content is found.